• Re: E-ink calendar and ToDo list

    From Giangi72@3:770/3 to All on Thu Dec 16 15:03:24 2021
    Il 16/12/2021 15:00, Giangi72 ha scritto:

    1) It have to be without power adapter so I need a "battery", which is
    the cheapest way to feed the raspberry? I googled for it but I see
    battery hats for 3-4 € and UPS hats for 30-40 € but I don't undestand
    the differences between them.
    2) I would like to use Visual Studio Code to develop the software side.
    For the power consumes is it better to install a full OS (Raspberry Pi
    OS with desktop) or a limited one (Raspberry Pi OS Lite) and develop in different ways?

    3) Is there any way to suspend the raspberry after refresh and restart
    it again before next refresh to save power?

    thanks again
    Giangi

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  • From Giangi72@3:770/3 to All on Thu Dec 16 15:00:36 2021
    Hello everyone,
    I'm a new user in this newsgroup.
    I would like to create a personal google calendar and ToDo list using a,
    e-ink display without power adapter: a frame with display in it on the wall. The display has a power consume of 48mW during refresh and I would like
    to refresh it once at hour (maybe 30 minutes), obviously it will be
    connected by wi-fi.
    Once a week/month/year I can take it from the wall, charge it an the put
    it again on the wall.

    I have some questions to people more expert than me:
    1) It have to be without power adapter so I need a "battery", which is
    the cheapest way to feed the raspberry? I googled for it but I see
    battery hats for 3-4 € and UPS hats for 30-40 € but I don't undestand
    the differences between them.
    2) I would like to use Visual Studio Code to develop the software side.
    For the power consumes is it better to install a full OS (Raspberry Pi
    OS with desktop) or a limited one (Raspberry Pi OS Lite) and develop in different ways?

    These are the first dubts I have.
    If you have more informations or dubts please don't be shy :-)
    Many thanks in advance
    Giangi

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  • From Dennis Lee Bieber@3:770/3 to All on Thu Dec 16 11:21:42 2021
    On Thu, 16 Dec 2021 15:00:37 +0100, Giangi72 <invalid@invalid.net>
    declaimed the following:

    The display has a power consume of 48mW during refresh and I would like
    to refresh it once at hour (maybe 30 minutes), obviously it will be
    connected by wi-fi.

    What voltage/amperage? That may have a limitation on what type of power source you can use.

    Once a week/month/year I can take it from the wall, charge it an the put
    it again on the wall.

    I have some questions to people more expert than me:
    1) It have to be without power adapter so I need a "battery", which is
    the cheapest way to feed the raspberry? I googled for it but I see
    battery hats for 3-4 € and UPS hats for 30-40 € but I don't undestand
    the differences between them.

    UPS is "Uninterruptible Power Supply" -- a system that uses wall power most of the time, but can switch to battery backup when the wall power
    fails -- and can do this in a way that the attached device does not notice
    a power glitch. If it is a good one, when the wall power comes back up, it
    will recharge the battery. It may also (via monitoring software and GPIO or such) signal to the R-Pi if both wall power has been lost, AND the battery
    is running down -- so the R-Pi can perform a clean shutdown.

    Obviously needs a power adapter for normal operation.

    In contrast, a plain battery is just that... a battery that can run down. Linux systems do NOT like having the power pulled -- it can lose unwritten data (at best) requiring a journal rebuild of the file system on
    next start-up, up to corrupting the file system beyond recovery.

    2) I would like to use Visual Studio Code to develop the software side.
    For the power consumes is it better to install a full OS (Raspberry Pi
    OS with desktop) or a limited one (Raspberry Pi OS Lite) and develop in >different ways?

    I'm tempted to suggest you develop on one device using a full desktop if you require any graphical editor/development environment, and then
    install the application on a device without a desktop system. Your
    application sounds like it could run using the smallest WiFi enabled R-Pi,
    but for development (especially if using C/C++ or other compiled language) might be better on a larger/more powerful R-Pi model.

    Does a library already exist for the display, or do you have to create that too?

    Actually, have you even done a search to see if this has been done already? The first page of a search on Google found two implementations
    (the first having way too many reviews/references on the page <G>)

    https://www.tomshardware.com/news/raspberry-pi-e-ink-google-candar https://github.com/speedyg0nz/MagInkCal

    https://hackaday.com/2019/02/11/get-organized-with-this-raspberry-pi-e-ink-calendar/


    --
    Wulfraed Dennis Lee Bieber AF6VN
    wlfraed@ix.netcom.com http://wlfraed.microdiversity.freeddns.org/

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  • From Giangi72@3:770/3 to All on Thu Dec 16 17:58:30 2021
    Il 16/12/2021 17:21, Dennis Lee Bieber ha scritto:
    On Thu, 16 Dec 2021 15:00:37 +0100, Giangi72 <invalid@invalid.net>
    declaimed the following:

    The display has a power consume of 48mW during refresh and I would like
    to refresh it once at hour (maybe 30 minutes), obviously it will be
    connected by wi-fi.

    What voltage/amperage? That may have a limitation on what type of power source you can use.

    It SHOULD be powered by raspberry, the power consume of display during
    NOT refresh should be 0 (it is an e-ink, the consume should be only
    during refresh).
    During refresh, I read on datasheet
    Typical operating current 6.6 mA

    Once a week/month/year I can take it from the wall, charge it an the put
    it again on the wall.

    I have some questions to people more expert than me:
    1) It have to be without power adapter so I need a "battery", which is
    the cheapest way to feed the raspberry? I googled for it but I see
    battery hats for 3-4 € and UPS hats for 30-40 € but I don't undestand
    the differences between them.

    UPS is "Uninterruptible Power Supply" -- a system that uses wall power most of the time, but can switch to battery backup when the wall power
    fails -- and can do this in a way that the attached device does not notice
    a power glitch. If it is a good one, when the wall power comes back up, it will recharge the battery. It may also (via monitoring software and GPIO or such) signal to the R-Pi if both wall power has been lost, AND the battery
    is running down -- so the R-Pi can perform a clean shutdown.

    Obviously needs a power adapter for normal operation.

    In contrast, a plain battery is just that... a battery that can run down. Linux systems do NOT like having the power pulled -- it can lose unwritten data (at best) requiring a journal rebuild of the file system on next start-up, up to corrupting the file system beyond recovery.

    Perfect, but are there any battery hats (cheaper) that can tell to
    raspberry how many remaning charge they have?
    e.g.
    https://thepihut.com/products/li-ion-battery-hat-for-raspberry-pi
    but I found the same, in the past, a 3-4€

    If I'm able to understand how many charge remains I can send a visible
    warning: mail, notification, ...

    2) I would like to use Visual Studio Code to develop the software side.
    For the power consumes is it better to install a full OS (Raspberry Pi
    OS with desktop) or a limited one (Raspberry Pi OS Lite) and develop in
    different ways?

    I'm tempted to suggest you develop on one device using a full desktop if you require any graphical editor/development environment, and then
    install the application on a device without a desktop system. Your application sounds like it could run using the smallest WiFi enabled R-Pi, but for development (especially if using C/C++ or other compiled language) might be better on a larger/more powerful R-Pi model.

    This could be a good idea, or develop on a full OS sd card and the swap
    to a liter SD card.
    But in terms of power consume: what happens if I use a full desktop OS
    and the switch off the desktop environvent?

    Does a library already exist for the display, or do you have to create that too?

    No, no everything already exists https://www.waveshare.com/wiki/7.5inch_e-Paper_HAT_(B)

    Actually, have you even done a search to see if this has been done already? The first page of a search on Google found two implementations
    (the first having way too many reviews/references on the page <G>)

    https://www.tomshardware.com/news/raspberry-pi-e-ink-google-candar https://github.com/speedyg0nz/MagInkCal

    I know this project, but it is in pyton, some informations are very
    useful but not the whole project

    https://hackaday.com/2019/02/11/get-organized-with-this-raspberry-pi-e-ink-calendar/

    This is new to me. Also this is interesting, I think I'll steal the
    button to refresh idea but ...pyton again.

    My problem is now mainly on power and power duration: which cheap hat
    use to power the raspberry.
    And then my later question to reduce the power consume

    3) Is there any way to suspend the raspberry after refresh and restart
    it again before next refresh to save power?

    Many thanks
    Giangi

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  • From Dennis Lee Bieber@3:770/3 to All on Thu Dec 16 16:51:28 2021
    On Thu, 16 Dec 2021 17:58:30 +0100, Giangi72 <invalid@invalid.net>
    declaimed the following:

    During refresh, I read on datasheet
    Typical operating current 6.6 mA


    Taking your previous statement of 48mW and this 6.6mA, that yields a 7.3V power source (W = V * A). Raspberry-Pi's provide 5V and 3.3V (and
    GPIOs can be killed if fed more than 3.3V; the 5V is from the input power supply and primarily provided to USB ports)

    Perfect, but are there any battery hats (cheaper) that can tell to
    raspberry how many remaning charge they have?
    e.g.
    https://thepihut.com/products/li-ion-battery-hat-for-raspberry-pi
    but I found the same, in the past, a 3-4€


    Did you look at the documentation for that unit?

    """
    7. Discharge time is based on current capacity of battery. 800mA could
    power Raspberry Pi 3B+ (The consumption of Pi 3B+ is larger than Pi 3B) for about 50min, power Pi Zero W for about 2~3h. (no-load state)
    """

    An R-Pi Zero with NO LOAD, can manage less than three hours!

    Most 14500 LiIon batteries run around 800mAH at 3.6V, and are sized like a AA battery.

    Contrast with https://www.amazon.com/Pisugar2-Portable-Platform-Raspberry-Accessories/dp/B08D8PPCKN/ref=sr_1_2?keywords=raspberry+pi+battery+pack&qid=1639688505&sr=8-2
    """
    It can also shut down safely when the power is too low to avoid data loss
    and damage caused by sudden power failure.
    """
    Onboard RTC: The onboard RTC makes it possible to obtain real time in any network condition. Timing boot function is also provided.
    """

    Even this only states "Battery Life 7 Hours" for 3B 3B+ 4B sized units -- that's a 5000mAH battery, 6 times the capacity of a 14500.




    This could be a good idea, or develop on a full OS sd card and the swap
    to a liter SD card.
    But in terms of power consume: what happens if I use a full desktop OS
    and the switch off the desktop environvent?

    It may not be that easy (especially with that nasty systemd start-up logic, in place of easily understood initd -- with initd you'd have to
    change the run level to a straight shell/console only mode [I'm not sure exactly how you specify the boot run-level -- my experience shows systems booting in operator console only, then shifting to a multiple console mode where function keys toggle between consoles, and finally shifting to
    X-window mode]).

    X-window systems are client server, originally the concept was that a mainframe (or mini computer) ran user applications as "clients" and the
    remote graphical terminal ran the display server. The desktop is a client
    (that runs other graphical clients) sending display instructions to the
    server -- which in many computers these days is also running on the same system. You'd have to shut down both the server software, AND the client (desktop) system.

    https://www.waveshare.com/wiki/7.5inch_e-Paper_HAT_(B)



    I know this project, but it is in pyton, some informations are very
    useful but not the whole project


    So what is wrong with Python -- it IS the language the R-PI foundation targeted for users <G>

    For an hourly/half-hourly (or whatever rate you want to refresh) you don't need the speed from using a compiled language. And the easiest way to
    set up that timing would be to have the application merely do one refresh
    and exit -- and invoke it using a crontab entry specifying how often to
    run.


    My problem is now mainly on power and power duration: which cheap hat
    use to power the raspberry.
    And then my later question to reduce the power consume

    3) Is there any way to suspend the raspberry after refresh and restart
    it again before next refresh to save power?

    Not easily -- Some of the R-Pi is always powered (notice that if you do a "shutdown" the red power LED still is lit, and there is no button/input
    to trigger a clean shutdown (Beaglebone Black has a momentary contact power button which does a clean shutdown, and initiates a boot from the Off state
    -- the only circuit drawing power when "off" might be the voltage/power regulator chip; it gets a signal from the power button to start the
    power-up sequence [this is implicit if one is plugging in a power supply].
    I don't know if there is a way to tap into the power button to allow an external circuit to start boot-up.).

    While you can easily program a shutdown (especially on an R-Pi where using "sudo" doesn't trigger a prompt for login password; Beaglebones are configured by default to need the password when invoking "sudo"); you'd
    need an external circuitry to drop the power to the R-Pi, and then reapply power to start a boot up.

    You'd also have the problem of making sure the application isn't run until the WiFi link is active (to get calendar updates), and that the time-of-day is valid (without a battery-backed RTC for time-of-day, R-Pi
    and BBB both make use of a fake clock; that is, they periodically write the current time-of-day to a file, and initialize the software time-of-day
    clock on boot by reading the last saved time-of-day).

    WiFi is likely the biggest power drain you have on an R-Pi.


    --
    Wulfraed Dennis Lee Bieber AF6VN
    wlfraed@ix.netcom.com http://wlfraed.microdiversity.freeddns.org/

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  • From Giangi72@3:770/3 to All on Fri Dec 17 11:44:28 2021
    Il 16/12/2021 20:05, Andy Burns ha scritto:
    Giangi72 wrote:

    My problem is now mainly on power and power duration: which cheap hat
    use to power the raspberry.
    And then my later question to reduce the power consume

    3) Is there any way to suspend the raspberry after refresh and restart
    it again before next refresh to save power?

    Maybe use an ESP32 instead of an RPi?

    I don't know ESP32, what I see is that it is an arduino-like board.
    From what I saw I'm not sure it is able to support complex software as
    google calendar as mentioned in another message, but I'm not an expert
    Some addtional informations here https://stackoverflow.com/questions/19766912/how-do-i-authorise-an-app-web-or-installed-without-user-intervention/19766913#19766913

    What are the main advantages to use ESP32 instead of Raspberry pi?
    Thanks
    Giangi

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  • From Theo@3:770/3 to invalid@invalid.net on Fri Dec 17 11:25:14 2021
    Giangi72 <invalid@invalid.net> wrote:
    I don't know ESP32, what I see is that it is an arduino-like board.
    From what I saw I'm not sure it is able to support complex software as google calendar as mentioned in another message, but I'm not an expert
    Some addtional informations here https://stackoverflow.com/questions/19766912/how-do-i-authorise-an-app-web-or-installed-without-user-intervention/19766913#19766913

    What are the main advantages to use ESP32 instead of Raspberry pi?

    ESP32 is a wifi microcontroller. Being a microcontroller, low power
    is part of its DNA. Microcontrollers can enter a low power state until something happens - for example your device sleeping until the next update
    is required. You can be sure that the device is actually going to idle for that time.

    An application class processor can't really do that, because there's too
    much other stuff going on. Maybe you could if you ran bare-metal, but not
    with a full Linux OS. Smartphones are a good example - you might get a week
    of idle, but once you have wifi and notifications and and... the battery
    life starts to drop.

    If you're going to run an e-ink screen to save power, it would be
    unfortunate if the CPU wasted most of it.

    On the other hand, e-readers are good examples of basic application-class
    cores (often comparable with the original Pi Zero) with e-ink, micro SD and wifi, but which aggressively turn those things off when not needed. An e-reader might be an interesting starting point for such a project - eg I
    have a Nook Simple Touch that runs Android (2.1 I think - despite being released in the Android 4 era, later Androids got more resource hungry so
    they went with an older version).

    Theo

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  • From Giangi72@3:770/3 to All on Fri Dec 17 12:34:20 2021
    Il 16/12/2021 22:51, Dennis Lee Bieber ha scritto:
    On Thu, 16 Dec 2021 17:58:30 +0100, Giangi72 <invalid@invalid.net>
    declaimed the following:

    During refresh, I read on datasheet
    Typical operating current 6.6 mA


    Taking your previous statement of 48mW and this 6.6mA, that yields a 7.3V power source (W = V * A). Raspberry-Pi's provide 5V and 3.3V (and
    GPIOs can be killed if fed more than 3.3V; the 5V is from the input power supply and primarily provided to USB ports)

    The display is directly connected to raspberry's GPIOs and use 3.3 V.
    But you are right, I checked the datasheet and I found different values
    than 48mW written on amazon.

    There are 2 datasheets: V2 and V3 and I don't know the differences

    V2 page 12: https://www.waveshare.com/w/upload/4/44/7.5inch_e-Paper_B_V2_Specification.pdf Image update current typical 8, max 12 mA
    Power panel (update) typical 26.4, max 45 mW
    =
    typical 3.3, max 3.75 V

    V3 page 9: https://www.waveshare.com/w/upload/8/8c/7.5inch-e-paper-b-v3-specification.pdf Typical power 21.78 mW
    Typical operating current 6.6 mA
    =
    3.3V

    Perfect, but are there any battery hats (cheaper) that can tell to
    raspberry how many remaning charge they have?
    e.g.
    https://thepihut.com/products/li-ion-battery-hat-for-raspberry-pi
    but I found the same, in the past, a 3-4€


    Did you look at the documentation for that unit?

    Sigh, no, just now.
    It was under "View More" then "wiki ...", then manual

    [CUT]
    This means there is no way to power raspberry by battery and let it last
    for at least a week?

    I know this project, but it is in pyton, some informations are very
    useful but not the whole project


    So what is wrong with Python -- it IS the language the R-PI foundation targeted for users <G>

    :-) you are absolutely right, simply it is not the language I usually use.
    I have a very low knowledge in pyton and I don't want to loose time
    learning it well.
    Additionally I would like to also implement a sort of ToDo list so I
    need to change the application.

    For an hourly/half-hourly (or whatever rate you want to refresh) you don't need the speed from using a compiled language. And the easiest way to set up that timing would be to have the application merely do one refresh
    and exit -- and invoke it using a crontab entry specifying how often to
    run.

    This is absolutely correct and wonderful suggestion.


    3) Is there any way to suspend the raspberry after refresh and restart
    it again before next refresh to save power?

    [CUT]
    WiFi is likely the biggest power drain you have on an R-Pi.

    Thanks for your detailed explanations, I surrender: no battery.
    If I connect it to a power source all my problems are washed away.
    Many thanks
    Giangi

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  • From Giangi72@3:770/3 to All on Fri Dec 17 12:59:58 2021
    Il 17/12/2021 00:25, Theo ha scritto:
    Andy Burns <usenet@andyburns.uk> wrote:
    Giangi72 wrote:

    My problem is now mainly on power and power duration: which cheap hat use to
    power the raspberry.
    And then my later question to reduce the power consume

    3) Is there any way to suspend the raspberry after refresh and restart it again
    before next refresh to save power?

    Maybe use an ESP32 instead of an RPi?

    That was my first thought. Although it depends how complicated the Google Calendar API is, and whether it's something the ESP software can handle. If it's basic JSON or something it'll probably be fine, but if it needs lots of stateful stuff (OAuth etc) that could be harder. Something like CalDav
    looks quite complicated.

    But maybe you could run that part on a server/a RPi and have the ESP
    poll it with simpler requests?

    This is a good idea, I can create a mini service on my web site and the application should only read the result

    Just to let you hate me better :-): what about power consumes?
    Is it possible to power it by battery and let it last for one week or more?

    I quite like the M5Stacks as neatly packaged ESP32 boards, with batteries
    and displays: https://shop.m5stack.com/products/m5paper-esp32-development-kit-960x540-4-7-eink-display-235-ppi?variant=37595977908396
    https://shop.m5stack.com/products/m5stack-esp32-core-ink-development-kit1-54-elnk-display?variant=37404426174636

    Thanks for your suggestions but the display is too small and I would
    like to put it in a beautiful frame.
    Thanks
    Giangi

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  • From Andy Burns@3:770/3 to All on Fri Dec 17 13:12:52 2021
    Giangi72 wrote:

    What are the main advantages to use ESP32 instead of Raspberry pi?

    putting it to deep sleep between updates, and boards with available LiPo battery
    management.

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  • From John Aldridge@3:770/3 to All on Fri Dec 17 13:41:14 2021
    In article <j23attFm984U1@mid.individual.net>, invalid@invalid.net
    says...

    This means there is no way to power raspberry by battery and let it last
    for at least a week?

    I think your options are...

    1. Use a Very Big battery. AFAIR, a PiZeroW draws around 250 mA on
    average, when idling, so something around 40 Ah at 5V. Say 20 Ah at 12V,
    after you've included the 12V->5V voltage converter. It'll be something
    like a car battery in size, and correspondingly expensive.

    2. Add some extra circuitry to completely power off the RPi between
    refreshes (making sure you wait until the RPi has shut down cleanly
    before cutting the power). I think you'd have to home-brew this
    circuitry.

    3. Use a different processor, e.g. Arduino, ESP32, RP2040. I don't have
    any personal experience, but I think these all support a low power deep-
    sleep mode from which you can wake on a timer.

    --
    John

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  • From Martin Gregorie@3:770/3 to John Aldridge on Fri Dec 17 14:16:26 2021
    On Fri, 17 Dec 2021 13:41:14 -0000, John Aldridge wrote:

    In article <j23attFm984U1@mid.individual.net>, invalid@invalid.net
    says...

    This means there is no way to power raspberry by battery and let it
    last for at least a week?

    I think your options are...

    1. Use a Very Big battery. AFAIR, a PiZeroW draws around 250 mA on
    average, when idling, so something around 40 Ah at 5V. Say 20 Ah at 12V, after you've included the 12V->5V voltage converter. It'll be something
    like a car battery in size, and correspondingly expensive.

    2. Add some extra circuitry to completely power off the RPi between
    refreshes (making sure you wait until the RPi has shut down cleanly
    before cutting the power). I think you'd have to home-brew this
    circuitry.

    3. Use a different processor, e.g. Arduino, ESP32, RP2040. I don't have
    any personal experience, but I think these all support a low power deep- sleep mode from which you can wake on a timer.

    The RP2040, aka PICO, may be what the OP wants. Its cheap, low power, can
    be made to sleep for a user-definable time, and is intended to be
    programmed in C/C++ or PICO-assembler. It has no OS - just a set of
    support code, including a C standard library. You link your application
    code with C library etc and the hardware-specific support libraries to
    get a binary blob. Load that into the PICO, connect power and it runs.
    All the documentation is on the PICO section of the RaspberryPi
    Foundation website so, if this sounds interesting, go and read the docs.

    The process of developing code for it looks similar to the way you'd
    program a Parallax STAMP or a PICAXE chip except that both of those are programmed using their own flavours of compiled integer BASIC while the
    PICO can be programmed in C/C++.

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  • From Giangi72@3:770/3 to All on Fri Dec 17 14:29:02 2021
    Il 17/12/2021 14:12, Andy Burns ha scritto:
    Giangi72 wrote:

    What are the main advantages to use ESP32 instead of Raspberry pi?

    putting it to deep sleep between updates, and boards with available LiPo battery management.

    Could you please give me more informations about the battery management.
    Only links is enough
    Thanks
    Giangi

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  • From Andy Burns@3:770/3 to All on Fri Dec 17 13:40:48 2021
    Giangi72 wrote:

    Andy Burns ha scritto:

    Giangi72 wrote:

    What are the main advantages to use ESP32 instead of Raspberry pi?

    putting it to deep sleep between updates, and boards with available LiPo
    battery management.

    Could you please give me more informations about the battery management.
    Only links is enough

    e.g. <https://unexpectedmaker.com/tinys2>

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  • From Theo@3:770/3 to Martin Gregorie on Fri Dec 17 15:04:32 2021
    Martin Gregorie <martin@mydomain.invalid> wrote:
    The RP2040, aka PICO, may be what the OP wants. Its cheap, low power, can
    be made to sleep for a user-definable time, and is intended to be
    programmed in C/C++ or PICO-assembler. It has no OS - just a set of
    support code, including a C standard library. You link your application
    code with C library etc and the hardware-specific support libraries to
    get a binary blob. Load that into the PICO, connect power and it runs.
    All the documentation is on the PICO section of the RaspberryPi
    Foundation website so, if this sounds interesting, go and read the docs.

    The process of developing code for it looks similar to the way you'd
    program a Parallax STAMP or a PICAXE chip except that both of those are programmed using their own flavours of compiled integer BASIC while the
    PICO can be programmed in C/C++.

    The RP2040 and the RPi Pico don't have networking. You can connect it via a wire to a USB port, but that's not what the OP wants.

    It seems the Arduino people have an 'Nano RP2040 Connect' which has a u-blox NINA WiFi module on it... that has an ESP32 inside.

    So you might as well just use an ESP32 to begin with.

    Theo

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  • From Giangi72@3:770/3 to All on Fri Dec 17 17:08:02 2021
    Il 17/12/2021 14:40, Andy Burns ha scritto:

    What are the main advantages to use ESP32 instead of Raspberry pi?

    putting it to deep sleep between updates, and boards with available
    LiPo battery management.

    Could you please give me more informations about the battery management.
    Only links is enough

    e.g. <https://unexpectedmaker.com/tinys2>

    Thanks
    Giangi

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  • From Andy Burns@3:770/3 to All on Fri Dec 17 17:04:36 2021
    Giangi72 wrote:

    500mA Max charging current."

    1) What does it means? If I have a 700mA or 1000mA battery? Sorry for this newbie question.

    I presume you mean 700mAh or 1000mAh capacity, rather than 500mA charging current, just mean it'll take between 90 minutes and 2 hours to charge

    2) I don't understand how to charge the battery once  it is connected to the board. Using usb port or detaching it and charging it externally?

    whenever USB power is supplied, the board will charge the battery.

    --- SoupGate-Win32 v1.05
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  • From Giangi72@3:770/3 to All on Fri Dec 17 17:32:18 2021
    Il 17/12/2021 16:04, Theo ha scritto:

    The RP2040 and the RPi Pico don't have networking. You can connect it via a wire to a USB port, but that's not what the OP wants.

    It seems the Arduino people have an 'Nano RP2040 Connect' which has a u-blox NINA WiFi module on it... that has an ESP32 inside.

    So you might as well just use an ESP32 to begin with.

    Thanks to everyone.
    I think the ESP32 + web service is the best solution.
    I have found this board with integrated battery management and socket https://www.aliexpress.com/item/1005003416635072.html?spm=a2g0o.cart.0.0.31be3c00pggd6r&mp=1
    and https://www.aliexpress.com/item/1005002412550877.html?spm=a2g0o.cart.0.0.31be3c00pggd6r&mp=1
    and I read
    "Lithium battery interface(battery not include), 500mA Max charging
    current."

    1) What does it means? If I have a 700mA or 1000mA battery? Sorry for
    this newbie question.
    2) I don't understand how to charge the battery once it is connected to
    the board. Using usb port or detaching it and charging it externally?

    Many thanks
    Giangi

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  • From Giangi72@3:770/3 to All on Fri Dec 17 18:22:40 2021
    Il 17/12/2021 18:04, Andy Burns ha scritto:
    Giangi72 wrote:

    500mA Max charging current."

    1) What does it means? If I have a 700mA or 1000mA battery? Sorry for
    this newbie question.

    I presume you mean 700mAh or 1000mAh capacity, rather than 500mA
    charging current, just mean it'll take between 90 minutes and 2 hours to charge

    Sorry, obviously my fault it was mAh, I read 500mA and wrote 700mA.
    My newbie question is:
    I read "500mA Max charging current", if I have a 700mAh battery will it
    work? Obviously with longer charging times.

    2) I don't understand how to charge the battery once  it is connected
    to the board. Using usb port or detaching it and charging it externally?

    whenever USB power is supplied, the board will charge the battery.

    Perfect, thanks.
    Giangi

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  • From Dennis Lee Bieber@3:770/3 to All on Fri Dec 17 12:52:00 2021
    On Fri, 17 Dec 2021 11:44:28 +0100, Giangi72 <invalid@invalid.net>
    declaimed the following:


    What are the main advantages to use ESP32 instead of Raspberry pi?

    It is an embedded microCONTROLLER -- no OS (unless one ports FreeRTOS to it; FreeRTOS is /not/ an OS as you may think, but rather a real-time
    kernel that allows for priority-based threads within the application. I
    don't think your application needs threads/processes -- unless WiFi/network stack needs one). The installed application runs out of flash memory, it doesn't get loaded into RAM before it can run -- so basically, the
    application runs as soon as the processor initializes. That would simplify
    a power cycle mode (you'd still have to figure out how to time a start-up sequence -- though some may have a sleep mode using a separate clock chip
    to wake up).

    The R-Pi is a full COMPUTER with high-level OS. It is not considered "real time". It has user accounts/privileges/etc., separation between application and kernel operations.

    While the basic Arduino is an 8-bit AVR, the old Arduino Due (and some newer models) use 16/32-bit ARM chips and have more RAM (RAM is basically
    only used for variable storage -- basically a large register bank).
    AdaFruit Metro M4 is also an ARM based board with Arduino Uno pin-out.
    Native mode is that a (Circuit)Python interpreter runs as the main
    application, with user program loaded into a separate flash area. The Grand Central board has the layout of an Arduino Mega. You can replace the circuitPython interpreter with an Arduino type boot-loader, and use Arduino
    IDE for programming.

    Biggest drawback is that many do not have native networking/WiFi -- so one needs an add-on board for network connections, and applications need to include the suitable libraries to manage the network traffic; it is not
    part of some amorphous OS. (TIVA TM4C1294 launchpads do have Ethernet, but
    one still needs to use a library linked into one's code).

    And all of these would benefit from an add-on battery-backed up RTC (microcontrollers don't even attempt to keep "wall clock" time; they just
    count clock ticks from last boot up).



    --
    Wulfraed Dennis Lee Bieber AF6VN
    wlfraed@ix.netcom.com http://wlfraed.microdiversity.freeddns.org/

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  • From Dennis Lee Bieber@3:770/3 to All on Fri Dec 17 13:40:18 2021
    On Fri, 17 Dec 2021 13:41:14 -0000, John Aldridge <jpsa@cantab.net>
    declaimed the following:


    1. Use a Very Big battery. AFAIR, a PiZeroW draws around 250 mA on
    average, when idling, so something around 40 Ah at 5V. Say 20 Ah at 12V, >after you've included the 12V->5V voltage converter. It'll be something
    like a car battery in size, and correspondingly expensive.

    Probably closer to a motorcycle battery <G> for the 10-20Ah 12V. Motorcycle batteries can be picked up in one hand.

    Might want a deep discharge model (trolling motor style), but those will be full (car) battery size. Regular (starter motor) batteries are
    designed for high current draw over a short period of time -- 100+ Amps for 5-15 seconds. They aren't designed for long term drains, even dropping
    below around 9.5V will damage one. You'd have to keep a float charger on
    the battery -- and maybe air vents as they may give off noxious fumes.

    https://www.outoftheww.com/projects/what-does-amp-hour-mean
    Two 3.6V 2000mAH cells would provide 7.2V 2AH on a barrel connector (most
    of these embedded boards are designed for 6-9 (or 6-12) volt via connector
    and have an on board regulator to produce 5V and 3.3V.

    Charging Li-Ion batteries is not simple, advanced charging circuits include temperature sensors to detect when the charge has peaked and avoid overheating the battery.



    3. Use a different processor, e.g. Arduino, ESP32, RP2040. I don't have
    any personal experience, but I think these all support a low power deep- >sleep mode from which you can wake on a timer.

    https://www.arduino.cc/en/Reference/LowPowerDeepSleep https://www.arduino.cc/en/Reference/LowPowerIdle

    With a time in milliseconds, the longest sleep time may still be just a few seconds -- on a board with 16-bit integers/registers, 32768mSec -> 32 Seconds between timed wakes.

    Calling without a sleep time means it only wakes on an external event https://www.arduino.cc/en/Reference/LowPowerAttachInterruptWakeup

    NOTE: the above are only available on some of the ARM core Arduino
    boards. cf: https://www.arduino.cc/en/Reference/ArduinoLowPower

    If you can find one, https://store-usa.arduino.cc/products/arduino-mkr1000-wifi?selectedStore=us supports the low power sleep, and has WiFi on-board.

    https://store-usa.arduino.cc/products/arduino-uno-wifi-rev2?selectedStore=us On-board WiFi and TCP stack, but doesn't support low power sleep.


    --
    Wulfraed Dennis Lee Bieber AF6VN
    wlfraed@ix.netcom.com http://wlfraed.microdiversity.freeddns.org/

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  • From The Natural Philosopher@3:770/3 to Dennis Lee Bieber on Fri Dec 17 19:10:16 2021
    On 17/12/2021 18:40, Dennis Lee Bieber wrote:
    Charging Li-Ion batteries is not simple, advanced charging circuits
    include temperature sensors to detect when the charge has peaked and avoid overheating the battery.

    In cars perhaps. Not at lower capacities. Temperature sensors do not
    detect 'when the battery has charged' on Li-Ion. Voltage detects that.
    The temperature sensors on big vehicle packs are there for safety, in
    case a cell goes bad and overheats.


    The very simple 'charge each cell at less than the hourly rate to 4.2v
    and no more' algorithm dominates hobby chargers.

    The R/C model community has all the bits and pieces to charge packs and
    the requisite circuitry to drop the voltage to 5V for avionics - or Pi -
    usage.
    e.g.

    https://hobbyking.com/en_us/zippy-compact-8000mah-2s1p-30c.html
    = 8 Ah 7.4v battery.

    https://hobbyking.com/en_us/turnigy-5a-8-26v-sbec-for-lipo.html
    = Switched mode 5V output regulator

    https://hobbyking.com/en_us/turnigy-e3-compact-2s-3s-lipo-charger-100-240v-eu-plug.html
    = 3 x 800mAh balancing charger.

    Put that lot together and you have a system that will deliver ~5V/1A
    average for as long as the mains is on, and for about 10 hours if the
    mains goes out.


    --
    "Socialist governments traditionally do make a financial mess. They
    always run out of other people's money. It's quite a characteristic of them"

    Margaret Thatcher

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  • From scott@alfter.diespammersdie.us@3:770/3 to invalid@invalid.net on Mon Dec 20 23:05:36 2021
    Giangi72 <invalid@invalid.net> wrote:
    [CUT]
    This means there is no way to power raspberry by battery and let it last
    for at least a week?

    It's possible...it's just a matter of figuring out how big a battery pack
    would do that. Someone else theorized that a pack built of 14500 Li-ion
    cells (two in series, presumably, through a buck converter to get 5V) might
    run a Raspberry Pi 3B+ for five hours. 18650s are more common and larger;
    for sake of argument, let's say you get 3x the runtime (2400 mAh) from an
    18650 as you'd get from a 14500. If two 18650s would run the aforementioned RPi 3B+ for 15 hours, 24 18650s in a 2S12P configuration would provide 7.5
    days of runtime.

    Whether a pack made of two dozen 18650s would be too large for your
    application is a question only you can answer. :)

    --
    _/_
    / v \ Scott Alfter (remove the obvious to send mail)
    (IIGS( https://alfter.us/ Top-posting!
    \_^_/ >What's the most annoying thing on Usenet?

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  • From Folderol@3:770/3 to scott@alfter.diespammersdie.us on Tue Dec 21 16:46:08 2021
    On Mon, 20 Dec 2021 23:05:36 GMT
    scott@alfter.diespammersdie.us wrote:

    Giangi72 <invalid@invalid.net> wrote:
    [CUT]
    This means there is no way to power raspberry by battery and let it last
    for at least a week?

    It's possible...it's just a matter of figuring out how big a battery pack >would do that. Someone else theorized that a pack built of 14500 Li-ion >cells (two in series, presumably, through a buck converter to get 5V) might >run a Raspberry Pi 3B+ for five hours. 18650s are more common and larger; >for sake of argument, let's say you get 3x the runtime (2400 mAh) from an >18650 as you'd get from a 14500. If two 18650s would run the aforementioned >RPi 3B+ for 15 hours, 24 18650s in a 2S12P configuration would provide 7.5 >days of runtime.

    Whether a pack made of two dozen 18650s would be too large for your >application is a question only you can answer. :)


    I wouldn't advise it! Once you start stacking up large numbers of batteries all sorts of load balancing issues become apparent - both for charge and discharge.

    --
    Basic
    --- SoupGate-Win32 v1.05
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  • From Martin Gregorie@3:770/3 to Folderol on Tue Dec 21 19:21:06 2021
    On Tue, 21 Dec 2021 16:46:09 +0000, Folderol wrote:


    I wouldn't advise it! Once you start stacking up large numbers of
    batteries all sorts of load balancing issues become apparent - both for charge and discharge.

    Quite, Unless you've got some cutting-edge chippery that can run for
    months of a 2032 coin cell, there are only about two sensible ways to go:

    1) use some sort of UPS with sufficient battery capacity to run your
    calendar for 2-3 hours until the power comes back AND has the ability to
    tell your system to do an orderly shutdown if the power hasn't come back
    and its battery is nearly flat. If you choose a Pi, as least some of the
    UPS HATs made for fitting to a Pi can't do that.

    2) Forget about using Internet time and use either a GPS receiver or one
    of the VLF frequency time broadcasts as your master time source. That
    might use:

    - the DCF77 German sime signal with Conrad part number 641138-92
    as receiver

    - http://www.buzzard.me.uk/jonathan/radioclock.html using the Rugbk (UK)
    time signal - it can be interfaced to the standard Linux time system
    using this software:
    http://www.buzzard.me.uk/jonathan/downloads/radioclk-1.0.tar.gz

    - one of the US time sources, WWVB or WWVH

    I've used Jonathon Buzzard's receiver and Rugby in the past: its 'just
    worked'

    I've also used GPS time - older Puck-style receivers can be picked up in FleaBay. They normally use an RS-232 serial connection as output, and
    good, inexpensive RS-232->USB adapters are easy to find.

    The benefit of of these time sources is that it doesn't matter if your
    calendar does get killed by a storm or power cut: when power comes back
    the system can re-boot and re-establish an accurate time in a few minutes
    at most. also, it will still work if the power cut took out your section
    of the internet.
    --- SoupGate-Win32 v1.05
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  • From Theo@3:770/3 to Martin Gregorie on Tue Dec 21 22:46:26 2021
    Martin Gregorie <martin@mydomain.invalid> wrote:
    The benefit of of these time sources is that it doesn't matter if your calendar does get killed by a storm or power cut: when power comes back
    the system can re-boot and re-establish an accurate time in a few minutes
    at most. also, it will still work if the power cut took out your section
    of the internet.

    The OP wants to display their Google Calendar and todo list in a frame on
    their wall. That requires an internet connection. You can't display the appointments in their calendar without fetching it from the internet - you could only have a generic day/date calendar which is not what they're asking for. I suppose you could cache the calendar in case the network goes down,
    and a third party time source would help with bring that back up, but that's
    a fairly niche use case, and no help if the calendar is later changed.

    And so the problem is that the OP needs an internet connection but the power consumption is too high to run a Pi full time unless the battery is
    implausibly large to mount on the wall. The key is thus turning things off
    - either running a Pi on some kind of timeswitch, or using something that is better at entering a low power sleep mode.

    Finding out the time is not the problem, getting the calendar updates is.
    The dilemma is that something that can handle the complexity of talking to
    the Google servers is probably not low power enough to run from a battery in
    a wall frame for a week/month/year. Which is what makes me think a two-box solution is the way forward.

    Theo
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  • From Martin Gregorie@3:770/3 to Theo on Tue Dec 21 23:32:50 2021
    On 21 Dec 2021 22:46:27 +0000 (GMT), Theo wrote:

    Finding out the time is not the problem, getting the calendar updates
    is. The dilemma is that something that can handle the complexity of
    talking to the Google servers is probably not low power enough to run
    from a battery in a wall frame for a week/month/year. Which is what
    makes me think a two-box solution is the way forward.

    Yes, that or using a UPS with a smaller 1-2 hour battery, which probably
    would keep it up indefinitely with mains power thats as reliable as here
    or in most of the EU.
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  • From Axel Berger@3:770/3 to Theo on Wed Dec 22 09:16:18 2021
    Theo wrote:
    That requires an internet connection. You can't display the
    appointments in their calendar without fetching it from the internet - you could only have a generic day/date calendar which is not what they're asking for.

    That's not true. All my calendars are local to my phone and not synced
    to anything not fully under my control. I regularly save backups over my
    LAN at home and could import that to any other local calendar.

    In the present case you do have a point though, unless the OP is
    satisfied with having his appointments on the wall at home and nowhere
    else. But that too does not need the internet. Syncing between the
    (presumably) phone and the wall box over the LAN when at home would
    suffice.


    --
    /\ No | Dipl.-Ing. F. Axel Berger Tel: +49/ 221/ 7771 8067
    \ / HTML | Roald-Amundsen-Strae 2a Fax: +49/ 221/ 7771 8069
    X in | D-50829 Kln-Ossendorf http://berger-odenthal.de
    / \ Mail | -- No unannounced, large, binary attachments, please! --

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  • From Ahem A Rivet's Shot@3:770/3 to Axel Berger on Wed Dec 22 08:50:32 2021
    On Wed, 22 Dec 2021 09:16:19 +0100
    Axel Berger <Spam@Berger-Odenthal.De> wrote:

    Theo wrote:
    That requires an internet connection. You can't display the
    appointments in their calendar without fetching it from the internet -
    you could only have a generic day/date calendar which is not what
    they're asking for.

    That's not true. All my calendars are local to my phone and not synced

    The OP did specify *Google* calendar - which I rather think does require a public internet connection.

    There are of course other solutions that do not but from the perspective of a battery powered, wireless device on the wall it makes no difference whether the data is on a local server, at Google or elsewhere it
    has to be accessed using IP - in other words over an internet connection
    and it makes no difference whether the scope of that connection is global
    or local.

    --
    Steve O'Hara-Smith
    Odds and Ends at http://www.sohara.org/

    --- SoupGate-Win32 v1.05
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  • From Theo@3:770/3 to Axel Berger on Wed Dec 22 09:29:58 2021
    Axel Berger <Spam@berger-odenthal.de> wrote:
    Theo wrote:
    That requires an internet connection. You can't display the
    appointments in their calendar without fetching it from the internet - you could only have a generic day/date calendar which is not what they're asking
    for.

    That's not true. All my calendars are local to my phone and not synced
    to anything not fully under my control. I regularly save backups over my
    LAN at home and could import that to any other local calendar.

    In the present case you do have a point though, unless the OP is
    satisfied with having his appointments on the wall at home and nowhere
    else. But that too does not need the internet. Syncing between the (presumably) phone and the wall box over the LAN when at home would
    suffice.

    Like I said, the OP's calendar lives on Google Calendar. You can't fetch
    that without internet, because that calendar lives in the cloud. You can
    sync to something locally (a server/phone/another Pi), and then the wall
    frame fetches from there, which is the two-box solution I suggested. If you want a one-box solution you need internet on your one box, there's no
    getting around that.

    You can of course have a wall frame without an internet connection, to which you enter calendar entries on a touch screen or SD card or whatever. But
    that is an entirely different problem from the one the OP asked for, which
    was something to show live updates from their Google Calendar. As is
    worrying about getting the time from GPS, which is also a problem the OP doesn't have.

    Theo

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  • From Ahem A Rivet's Shot@3:770/3 to Theo on Wed Dec 22 10:22:32 2021
    On 22 Dec 2021 09:29:59 +0000 (GMT)
    Theo <theom+news@chiark.greenend.org.uk> wrote:

    Like I said, the OP's calendar lives on Google Calendar. You can't fetch that without internet, because that calendar lives in the cloud. You can sync to something locally (a server/phone/another Pi), and then the wall frame fetches from there, which is the two-box solution I suggested. If
    you want a one-box solution you need internet on your one box, there's no getting around that.

    Quite so, and the easiest (but expensive) way to achieve a one box solution would be to use an off the shelf e-ink tablet such as a Likebook,
    but given that they have a display in hand to use and want to DIY the ESP32 option being explored elsethread seems to fit the requirements.

    --
    Steve O'Hara-Smith
    Odds and Ends at http://www.sohara.org/

    --- SoupGate-Win32 v1.05
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  • From The Natural Philosopher@3:770/3 to Folderol on Wed Dec 22 11:56:00 2021
    On 21/12/2021 16:46, Folderol wrote:
    On Mon, 20 Dec 2021 23:05:36 GMT
    scott@alfter.diespammersdie.us wrote:

    Giangi72 <invalid@invalid.net> wrote:
    [CUT]
    This means there is no way to power raspberry by battery and let it last >>> for at least a week?

    It's possible...it's just a matter of figuring out how big a battery pack
    would do that. Someone else theorized that a pack built of 14500 Li-ion
    cells (two in series, presumably, through a buck converter to get 5V) might >> run a Raspberry Pi 3B+ for five hours. 18650s are more common and larger; >> for sake of argument, let's say you get 3x the runtime (2400 mAh) from an
    18650 as you'd get from a 14500. If two 18650s would run the aforementioned >> RPi 3B+ for 15 hours, 24 18650s in a 2S12P configuration would provide 7.5 >> days of runtime.

    Whether a pack made of two dozen 18650s would be too large for your
    application is a question only you can answer. :)


    I wouldn't advise it! Once you start stacking up large numbers of batteries all
    sorts of load balancing issues become apparent - both for charge and discharge.

    Not really. not for parelleling.

    The charge/voltage curves for cells are all similar, what differs is
    their capacity , so you might think it a problem as some cells charge up
    sooner than others, but that doesn't matter except at very high charge
    rates, because the same voltage represents the same state of charge for
    all the paralleled cells.


    But lithium batteries up to 10AH or even more are available. And at 14v
    nominal that's 140 Watt hours, and a Pi is about what - 5 watts or so?

    Or a car battery at 12v/70Ah nets you 160 hours

    Forget voltages and architectures - that's all soluble, just pick a
    battery that has the capacity you need and is happy to be trickle
    charged at slightly more than the Pis power draw.

    Pi draw is roughly 5W.
    a week is 7x24 = 168 hours

    168 hours times 5 W = 840 watt hours

    At 12v nominal that is 70 A/h which is spot on for a car or caravan battery.

    Looking at lithium cells I cant find a pack at less than £100 that comes close.

    440Wh at £156 and 22v is closest.

    So at least you know what you will be dealing with. A car or caravan
    battery.

    And then the problem resolves into how to step the voltage down for api
    - but that trivial - the amount of car to USB power converters is
    enormous, and likewise mains to trickle charge a caravan battery is off
    the self.


    --
    "Corbyn talks about equality, justice, opportunity, health care, peace,
    community, compassion, investment, security, housing...."
    "What kind of person is not interested in those things?"

    "Jeremy Corbyn?"

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  • From Andy Burns@3:770/3 to The Natural Philosopher on Wed Dec 22 12:13:16 2021
    The Natural Philosopher wrote:

    just pick a battery that has the capacity you need and is happy to be trickle charged at slightly more than the Pis  power draw.

    Once you reach the point where the battery is too large to fit within the frame on the wall, you either have to re-think whether a dangling power cable is acceptable, or use something other than a Pi ...

    --- SoupGate-Win32 v1.05
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  • From Martin Gregorie@3:770/3 to The Natural Philosopher on Wed Dec 22 12:56:50 2021
    On Wed, 22 Dec 2021 12:21:39 +0000, The Natural Philosopher wrote:

    Hasn't stopped renewable energy though, but then they never bothered to analyse it, they just built it for profit. irrespective of whether it
    worked or not.

    The only really crazy item on the table right now is so-called "Blue
    Hydrogen": the energetics of making it mean that burning coal is less environmentally damaging than making and using the 'Blue hydrogen'.

    --- SoupGate-Win32 v1.05
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  • From The Natural Philosopher@3:770/3 to Andy Burns on Wed Dec 22 12:21:38 2021
    On 22/12/2021 12:13, Andy Burns wrote:
    The Natural Philosopher wrote:

    just pick a battery that has the capacity you need and is happy to be
    trickle charged at slightly more than the Pis  power draw.

    Once you reach the point where the battery is too large to fit within
    the frame on the wall, you either  have to re-think whether a dangling
    power cable is acceptable, or use something other than a Pi ...

    Well exactly. peole seem to think that engineering is how to make stuff work

    Mostly the theoretic side of engineering is there to show you what stiff
    can never work, so its crazy to build it.

    Hasn't stopped renewable energy though, but then they never bothered to
    analyse it, they just built it for profit. irrespective of whether it
    worked or not.



    --
    I would rather have questions that cannot be answered...
    ...than to have answers that cannot be questioned

    Richard Feynman

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  • From Axel Berger@3:770/3 to Theo on Wed Dec 22 13:42:46 2021
    Theo wrote:
    Like I said, the OP's calendar lives on Google Calendar.

    Perhaps I misunderstood, or at least understood differently. For you a
    Google calendar is a calendar maintained for you by Google in their
    cloud. For me it's the calendar app in my phone and provided by Google.


    --
    /\ No | Dipl.-Ing. F. Axel Berger Tel: +49/ 221/ 7771 8067
    \ / HTML | Roald-Amundsen-Strae 2a Fax: +49/ 221/ 7771 8069
    X in | D-50829 Kln-Ossendorf http://berger-odenthal.de
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  • From The Natural Philosopher@3:770/3 to Martin Gregorie on Wed Dec 22 13:18:14 2021
    On 22/12/2021 12:56, Martin Gregorie wrote:
    On Wed, 22 Dec 2021 12:21:39 +0000, The Natural Philosopher wrote:

    Hasn't stopped renewable energy though, but then they never bothered to
    analyse it, they just built it for profit. irrespective of whether it
    worked or not.

    The only really crazy item on the table right now is so-called "Blue Hydrogen": the energetics of making it mean that burning coal is less environmentally damaging than making and using the 'Blue hydrogen'.

    I beg to differ. Everything on the table right now is crazy.
    I've spent many years analysing it, and the only thing that will
    actually work, other than a 97% drop in population and a return to the
    sort oft technology the Greens would understand. Presumably horses whose methane emanations would be forgotten in their sheer organicity... is
    nuclear power of some sort.

    Its abundant, uranium is ubiquitous, cheap and easily stockpiled, and
    comes already stored. The reactors are well understood known technology,
    and it transpires that radiation isn't nearly as dangerous as we had
    been led to believe, and we could easily achieve adequate safety at much
    lower cost.

    But nuclear isn't on the table. Every other permutation of artStudent™ thinking in terms of wacky schemes that were discarded generations ago
    by sane engineers, are the substance of dinner party chatterati.
    Hydrogen, carbon capture, Geothermal, tidal, wave, run of river,
    spinning flywheels, grid scale batteries molten salt tanks (that one
    might almost work with a nuke to drive it) heat pumps, electric cars.
    All of this to avoid the basic solution that nuclear power means, at a
    stroke, you don't need ANY of that crap.

    At current electricity wholesale prices, a nuclear fed simple restive
    heater would be one third the cost of a renewable fed heat pump in terms
    of electricity, and one tenth the installation cost. Not very efficient,
    but who cares? uranium is cheap as chips and there's tonnes and tonnes
    of it around and you don't need very much. E=mC^2 etc etc

    In short there is no shortage of cheap energy. Of all the problems
    society has, lack of cheap energy is not one of them. Only our refusal
    to embrace it is the problem

    That doesn't sort out the use of fossil fuels as chemical feedstocks of
    course, and as the only appropriate energy density energy source to fly transatlantic airliners, but we will all be locked down anyway, wont we.?





    --
    You can get much farther with a kind word and a gun than you can with a
    kind word alone.

    Al Capone

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Martin Gregorie@3:770/3 to The Natural Philosopher on Wed Dec 22 14:01:14 2021
    On Wed, 22 Dec 2021 13:18:14 +0000, The Natural Philosopher wrote:

    I beg to differ. Everything on the table right now is crazy.
    I've spent many years analysing it, and the only thing that will
    actually work, other than a 97% drop in population and a return to the
    sort oft technology the Greens would understand. Presumably horses whose methane emanations would be forgotten in their sheer organicity... is
    nuclear power of some sort.

    You're certainly right about population. That seems to be such a bad
    thing to say that its not even whispered about by anybody. Yet, any
    attempt to prevent global warming is doomed to failure without reductions
    in both the humam population and in individual (net) resource consumption.

    Its abundant, uranium is ubiquitous, cheap and easily stockpiled, and
    comes already stored. The reactors are well understood known technology,
    and it transpires that radiation isn't nearly as dangerous as we had
    been led to believe, and we could easily achieve adequate safety at much lower cost.

    Maybe it can be used, presumably in small factory-produced, reactors
    similar to those used in submarines, but studies I've seen point out that
    in terms of global warming, nukes still produce around 30% of the CO2
    from conventional thermal generation once mining and refining the stuff
    is taken into account:
    Storm van Leeuwen & Smith - http://www.stormsmith.nl/

    This also fails to ignore the problem of dealing with fanatics who think
    nuking someone or something would Be A Good Idea.

    I'n not against nuclear, PROVIDED THAT the problems of disposing of the radioactive waste from fuel preparation and the radioactive debris from decommissioning old plant can be sorted out. To date the solutions have
    mostly been to pile the junk in a corner and hope nobody notices it.

    That doesn't sort out the use of fossil fuels as chemical feedstocks of course, and as the only appropriate energy density energy source to fly transatlantic airliners,

    True enough, do we really need so many transatlantic airliners? Also, I'm seeing talk of running ships on Ammonia rather then heavy oil:

    NH3 + O2 => N2 + H2O + energy

    Is ammonia's energy content high enough to run an airliner? Gaseous
    hydrogen's isn't and nor is liquid hydrogen's once to take density/volume/ container mass into account.

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From The Natural Philosopher@3:770/3 to Martin Gregorie on Wed Dec 22 15:25:12 2021
    On 22/12/2021 14:01, Martin Gregorie wrote:
    On Wed, 22 Dec 2021 13:18:14 +0000, The Natural Philosopher wrote:

    I beg to differ. Everything on the table right now is crazy.
    I've spent many years analysing it, and the only thing that will
    actually work, other than a 97% drop in population and a return to the
    sort oft technology the Greens would understand. Presumably horses whose
    methane emanations would be forgotten in their sheer organicity... is
    nuclear power of some sort.

    You're certainly right about population. That seems to be such a bad
    thing to say that its not even whispered about by anybody. Yet, any
    attempt to prevent global warming is doomed to failure without reductions
    in both the humam population and in individual (net) resource consumption.


    Oh purlease. What 'global warming'?

    That stopped 20 years ago before they started 'adjusting' historical
    records to bring it back.

    The winter I am looking out at with frost on the ground is as bleak as
    it was 50 years ago.

    High levels of population are a proble'm but not because of lack of
    abundant cheap energy, or because of 'global warming

    Water is a far more urgent problem.



    Its abundant, uranium is ubiquitous, cheap and easily stockpiled, and
    comes already stored. The reactors are well understood known technology,
    and it transpires that radiation isn't nearly as dangerous as we had
    been led to believe, and we could easily achieve adequate safety at much
    lower cost.

    Maybe it can be used, presumably in small factory-produced, reactors
    similar to those used in submarines, but studies I've seen point out that
    in terms of global warming, nukes still produce around 30% of the CO2
    from conventional thermal generation once mining and refining the stuff
    is taken into account:
    Storm van Leeuwen & Smith - http://www.stormsmith.nl/


    Well its definitely in te renewable lobbies interst to pay for a study
    like that.

    It is of course nonsense. You need far more concretre per lifetime MWh generated in a windmill than a nuke


    This also fails to ignore the problem of dealing with fanatics who think nuking someone or something would Be A Good Idea.

    Anyone that stupid cannot build a bomb. They cant even build a bomb
    properly out of fertiliser which the IRA were much better at. If - say -
    Iran were to manange to deliver a nuke into Israel and set it off, can
    you imagine what would happen to Iran?


    I'n not against nuclear, PROVIDED THAT the problems of disposing of the radioactive waste from fuel preparation and the radioactive debris from decommissioning old plant can be sorted out. To date the solutions have mostly been to pile the junk in a corner and hope nobody notices it.

    No, all of the solutions that work perfectly well have been opposed by
    greens.

    The simplest and most obvious and cheapest solution would be to take it
    all out to the Marianas and throw it overboard in concrete cans. To join
    the 4 BILLION tonnes of uranium in et seas already

    uber low level waste is merely landfilled in steel cases that will do te
    100 years plus needed.

    uber high level is tomorrows nuclear fuel anyway.

    Intermediate - the sort of thousand year slightly radioactive and
    biological active shit - ceasium and the like - simply needs putting out
    of reach for 1000 years.
    How old are the pyramids? Stonehenge? I maen really galssifying it and stuffing it at the bottom of a disused coal mine in a sealed box is fine.

    If you want to REALLY scare yourself go and take a geiger counter to
    some disused radium/uranium mine in cornwall or dartmoor and exmoor.

    hundreds of times worse than a block of internediate waste.


    That doesn't sort out the use of fossil fuels as chemical feedstocks of
    course, and as the only appropriate energy density energy source to fly
    transatlantic airliners,

    True enough, do we really need so many transatlantic airliners? Also, I'm seeing talk of running ships on Ammonia rather then heavy oil:

    NH3 + O2 => N2 + H2O + energy

    Well ships of course will be nuclear powered - the weight of the
    shielding is not an issue - but ammonia is an interesting one. It would certainly be a way to replace natural gas to make fertiliser anyway,
    which is one of the big non-energy uses of it.

    Hydrogen my well be useful as a reducing agent for smelting metals,

    But its hard to see anything to beat long chain hydrocarbons for
    portable energy use, and its possible that dirt cheap nuclear poweer
    would allow reasonable yiled in stynethsis to make it viwable ..


    Is ammonia's energy content high enough to run an airliner? Gaseous hydrogen's isn't and nor is liquid hydrogen's once to take density/volume/ container mass into account.

    The volume gets you with hydrogen, plus safety and containment.

    "The energy density of ammonia is 22.5 MJ/kg at HHV, which is about half
    of that for typical hydrocarbon fuels but higher than metal hydrides (Zamfirescu and Dincer, 2008; Züttel et al., 2010). The raw energy
    density of liquid ammonia is 11.5 MJ/L, which is higher than the 8.491
    MJ/L for liquid hydrogen and the 4.5 MJ/L for compressed H2 at 690 bar
    and 15°C1 . Ammonia is a good energy vector for on-board hydrogen
    storage (Green, 1982; Klerke et al., 2008; Lan et al., 2012). However,
    safety is regarded as the major drawback of using ammonia as the fuel.
    Ammonia is toxic but it is detectable by humans in concentrations of
    just 1 ppm (Reich et al., 2001). Anhydrous ammonia is lighter than air
    then tends to disperse in the atmosphere. NH3 would be as safe as the
    use of gasoline as a transportation fuel (Olson and Holbrook, 2007). The ammonia released from an ammonia tank during a car accident may cause
    potential safety problem but this can be solved through the application
    of metal amines with low ammonia partial pressure (Klerke et al., 2008).

    Compared to hydrogen, ammonia is easier to be transported. It is much
    more energy efficient and much lower cost to produce, store, and deliver hydrogen as NH3 than as compressed and/or cryogenic hydrogen (Figure 1)
    (Olson and Holbrook, 2007). The infrastructure for ammonia already
    exists while for hydrogen, new fueling stations have to be built, which
    is a big investment (Lan et al., 2012)."

    https://www.frontiersin.org/articles/10.3389/fenrg.2014.00035/full

    The problem is that nitrogen don't oxidise and release energy, it
    oxidises and releases nastyShit.™

    You really want to reduce CO2 and water and make synthetic hydrocarbon.
    Trouble is there is bugger all CO2 in the atmosphere.

    So whereas it might be OK in a fuel cell in a car to go with ammonia, it
    isnt really going to make a nice pollution free plane ride.

    But what may in fact be the answer is bloody damned fast nuclear ships

    The larger the ship the less drag at a given speed per unit weight, and
    ships - containers and tankers - are conventionally operated to find a
    local minimum to the cost equation. Too fast and you burn more fuel per
    tonne mile, too slow and your cost of capital per tonne mile increases.

    If your fuel cost is peanuts but your cost of capital is high, and
    that's the case for a nukey ship, your accountant will tell you to push
    it to the maximum speed it can handle, and your engineers will start
    talking about lifting it out of the water on hydrofoils, or building an ekranoplane as well.

    If one wants to say, do southampton to new york in a day, before taking
    a high speed electric train, that's probably 120-150mph Well within ekranoplane range, but not sure about hydrofoils. its above the world
    record for a hovercraft, but not by much.

    A displacement nuclear ship should do it in 2-3 days nuclear subs have
    broken 50mph as well

    Anyway,. my point is that climate change and renewable energy are all
    red herrings, there is no shortage of nuclear fuel and all the problems
    in using it for land and sea based installations are eminently soluble.
    What there is is a r9ising shortage of affordable fossil fuels.

    All the problems with nuclear arise with portable power off grid. And
    basic chemical feedstocks. I think the feedstock chemistry is soluble,
    but portable off grid power is a real bugger.

    You really want carbon based fuels, but without fossil sources, carbon
    is in very short supply, and the only means of getting it out of the air
    is really using biofuel of some sort - algae and the like. Possible
    nuclear illuminated photosynthesis tanks to remove it from the air
    might work, but we are already right on the lower limits of CO2 in the
    air which allows plants to work efficiently - we really would need CO2
    up around 800ppm to get that to be efficient.








    --
    The theory of Communism may be summed up in one sentence: Abolish all
    private property.

    Karl Marx
    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Dennis Lee Bieber@3:770/3 to All on Wed Dec 22 12:18:28 2021
    On Wed, 22 Dec 2021 13:42:46 +0100, Axel Berger <Spam@Berger-Odenthal.De> declaimed the following:

    Theo wrote:
    Like I said, the OP's calendar lives on Google Calendar.

    Perhaps I misunderstood, or at least understood differently. For you a
    Google calendar is a calendar maintained for you by Google in their
    cloud. For me it's the calendar app in my phone and provided by Google.

    And that phone app typically duplicates appointments in Google's "cloud" to make them available to other devices that also have Google's calendar app (actually, some such apps incorporate multiple calendar
    provider APIs, allowing syncing across multiple "cloud" calendars).


    --
    Wulfraed Dennis Lee Bieber AF6VN
    wlfraed@ix.netcom.com http://wlfraed.microdiversity.freeddns.org/ --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Axel Berger@3:770/3 to Dennis Lee Bieber on Wed Dec 22 18:25:46 2021
    Dennis Lee Bieber wrote:
    And that phone app typically duplicates appointments in Google's
    "cloud" to make them available to other devices

    Typically yes. As with everything it's up to you to set it up right.


    --
    /\ No | Dipl.-Ing. F. Axel Berger Tel: +49/ 221/ 7771 8067
    \ / HTML | Roald-Amundsen-Strae 2a Fax: +49/ 221/ 7771 8069
    X in | D-50829 Kln-Ossendorf http://berger-odenthal.de
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    --- SoupGate-Win32 v1.05
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  • From David Higton@3:770/3 to Martin Gregorie on Wed Dec 22 17:27:26 2021
    In message <spt9f2$9na$1@dont-email.me>
    Martin Gregorie <martin@mydomain.invalid> wrote:

    using the Rugbk (UK) time signal

    I've used Jonathon Buzzard's receiver and Rugby in the past

    Just a reminder to everyone that the transmitter in question left
    Rugby many years ago and is nowadays in Anthorn, Cumbria. Rather
    more central to the British Isles.

    Still the same time signal.

    David

    --- SoupGate-Win32 v1.05
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  • From Ahem A Rivet's Shot@3:770/3 to Axel Berger on Wed Dec 22 17:49:56 2021
    On Wed, 22 Dec 2021 13:42:46 +0100
    Axel Berger <Spam@Berger-Odenthal.De> wrote:

    Theo wrote:
    Like I said, the OP's calendar lives on Google Calendar.

    Perhaps I misunderstood, or at least understood differently. For you a
    Google calendar is a calendar maintained for you by Google in their
    cloud. For me it's the calendar app in my phone and provided by Google.

    It is of course both of these - in the context of displaying it on
    a wall mounted device the cloud service seems to be the appropriate interpretation - running the app may however be part of an implementation.

    --
    Steve O'Hara-Smith
    Odds and Ends at http://www.sohara.org/

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Martin Gregorie@3:770/3 to The Natural Philosopher on Wed Dec 22 20:27:32 2021
    On Wed, 22 Dec 2021 15:25:12 +0000, The Natural Philosopher wrote:

    "The energy density of ammonia is 22.5 MJ/kg at HHV, which is about half
    of that for typical hydrocarbon fuels but higher than metal hydrides (Zamfirescu and Dincer, 2008; Züttel et al., 2010). The raw energy
    density of liquid ammonia is 11.5 MJ/L, which is higher than the 8.491
    MJ/L for liquid hydrogen and the 4.5 MJ/L for compressed H2 at 690 bar
    and 15°C1 . Ammonia is a good energy vector for on-board hydrogen
    storage (Green, 1982; Klerke et al., 2008; Lan et al., 2012). However,
    safety is regarded as the major drawback of using ammonia as the fuel. Ammonia is toxic but it is detectable by humans in concentrations of
    just 1 ppm (Reich et al., 2001). Anhydrous ammonia is lighter than air
    then tends to disperse in the atmosphere. NH3 would be as safe as the
    use of gasoline as a transportation fuel (Olson and Holbrook, 2007). The ammonia released from an ammonia tank during a car accident may cause potential safety problem but this can be solved through the application
    of metal amines with low ammonia partial pressure (Klerke et al., 2008).

    Compared to hydrogen, ammonia is easier to be transported. It is much
    more energy efficient and much lower cost to produce, store, and deliver hydrogen as NH3 than as compressed and/or cryogenic hydrogen (Figure 1) (Olson and Holbrook, 2007). The infrastructure for ammonia already
    exists while for hydrogen, new fueling stations have to be built, which
    is a big investment (Lan et al., 2012)."

    https://www.frontiersin.org/articles/10.3389/fenrg.2014.00035/full

    The problem is that nitrogen don't oxidise and release energy, it
    oxidises and releases nastyShit.™

    You really want to reduce CO2 and water and make synthetic hydrocarbon. Trouble is there is bugger all CO2 in the atmosphere.

    So whereas it might be OK in a fuel cell in a car to go with ammonia, it
    isnt really going to make a nice pollution free plane ride.

    But what may in fact be the answer is bloody damned fast nuclear ships

    The larger the ship the less drag at a given speed per unit weight, and
    ships - containers and tankers - are conventionally operated to find a
    local minimum to the cost equation. Too fast and you burn more fuel per
    tonne mile, too slow and your cost of capital per tonne mile increases.

    If your fuel cost is peanuts but your cost of capital is high, and
    that's the case for a nukey ship, your accountant will tell you to push
    it to the maximum speed it can handle, and your engineers will start
    talking about lifting it out of the water on hydrofoils, or building an ekranoplane as well.

    If one wants to say, do southampton to new york in a day, before taking
    a high speed electric train, that's probably 120-150mph Well within ekranoplane range, but not sure about hydrofoils. its above the world
    record for a hovercraft, but not by much.

    A displacement nuclear ship should do it in 2-3 days nuclear subs have
    broken 50mph as well

    Anyway,. my point is that climate change and renewable energy are all
    red herrings, there is no shortage of nuclear fuel and all the problems
    in using it for land and sea based installations are eminently soluble.
    What there is is a r9ising shortage of affordable fossil fuels.

    All the problems with nuclear arise with portable power off grid. And
    basic chemical feedstocks. I think the feedstock chemistry is soluble,
    but portable off grid power is a real bugger.

    You really want carbon based fuels, but without fossil sources, carbon
    is in very short supply, and the only means of getting it out of the air
    is really using biofuel of some sort - algae and the like. Possible
    nuclear illuminated photosynthesis tanks to remove it from the air
    might work, but we are already right on the lower limits of CO2 in the
    air which allows plants to work efficiently - we really would need CO2
    up around 800ppm to get that to be efficient.

    Thanks for the preceeding analysis of ammonia as a general purpose
    transport fuel.

    I'd not previously heard anything about it, pro or con, until a piece on
    Radio 4 mentioned it as a likely minimally polluting fuel for container ships, so it seemed logical to consider if ot would also work for aircraft: the
    answer seems to be 'yes'.

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From The Natural Philosopher@3:770/3 to Martin Gregorie on Thu Dec 23 09:49:46 2021
    On 22/12/2021 20:27, Martin Gregorie wrote:
    On Wed, 22 Dec 2021 15:25:12 +0000, The Natural Philosopher wrote:

    "The energy density of ammonia is 22.5 MJ/kg at HHV, which is about half
    of that for typical hydrocarbon fuels but higher than metal hydrides
    (Zamfirescu and Dincer, 2008; Züttel et al., 2010). The raw energy
    density of liquid ammonia is 11.5 MJ/L, which is higher than the 8.491
    MJ/L for liquid hydrogen and the 4.5 MJ/L for compressed H2 at 690 bar
    and 15°C1 . Ammonia is a good energy vector for on-board hydrogen
    storage (Green, 1982; Klerke et al., 2008; Lan et al., 2012). However,
    safety is regarded as the major drawback of using ammonia as the fuel.
    Ammonia is toxic but it is detectable by humans in concentrations of
    just 1 ppm (Reich et al., 2001). Anhydrous ammonia is lighter than air
    then tends to disperse in the atmosphere. NH3 would be as safe as the
    use of gasoline as a transportation fuel (Olson and Holbrook, 2007). The
    ammonia released from an ammonia tank during a car accident may cause
    potential safety problem but this can be solved through the application
    of metal amines with low ammonia partial pressure (Klerke et al., 2008).

    Compared to hydrogen, ammonia is easier to be transported. It is much
    more energy efficient and much lower cost to produce, store, and deliver
    hydrogen as NH3 than as compressed and/or cryogenic hydrogen (Figure 1)
    (Olson and Holbrook, 2007). The infrastructure for ammonia already
    exists while for hydrogen, new fueling stations have to be built, which
    is a big investment (Lan et al., 2012)."

    https://www.frontiersin.org/articles/10.3389/fenrg.2014.00035/full

    The problem is that nitrogen don't oxidise and release energy, it
    oxidises and releases nastyShit.™

    You really want to reduce CO2 and water and make synthetic hydrocarbon.
    Trouble is there is bugger all CO2 in the atmosphere.

    So whereas it might be OK in a fuel cell in a car to go with ammonia, it
    isnt really going to make a nice pollution free plane ride.

    But what may in fact be the answer is bloody damned fast nuclear ships

    The larger the ship the less drag at a given speed per unit weight, and
    ships - containers and tankers - are conventionally operated to find a
    local minimum to the cost equation. Too fast and you burn more fuel per
    tonne mile, too slow and your cost of capital per tonne mile increases.

    If your fuel cost is peanuts but your cost of capital is high, and
    that's the case for a nukey ship, your accountant will tell you to push
    it to the maximum speed it can handle, and your engineers will start
    talking about lifting it out of the water on hydrofoils, or building an
    ekranoplane as well.

    If one wants to say, do southampton to new york in a day, before taking
    a high speed electric train, that's probably 120-150mph Well within
    ekranoplane range, but not sure about hydrofoils. its above the world
    record for a hovercraft, but not by much.

    A displacement nuclear ship should do it in 2-3 days nuclear subs have
    broken 50mph as well

    Anyway,. my point is that climate change and renewable energy are all
    red herrings, there is no shortage of nuclear fuel and all the problems
    in using it for land and sea based installations are eminently soluble.
    What there is is a r9ising shortage of affordable fossil fuels.

    All the problems with nuclear arise with portable power off grid. And
    basic chemical feedstocks. I think the feedstock chemistry is soluble,
    but portable off grid power is a real bugger.

    You really want carbon based fuels, but without fossil sources, carbon
    is in very short supply, and the only means of getting it out of the air
    is really using biofuel of some sort - algae and the like. Possible
    nuclear illuminated photosynthesis tanks to remove it from the air
    might work, but we are already right on the lower limits of CO2 in the
    air which allows plants to work efficiently - we really would need CO2
    up around 800ppm to get that to be efficient.

    Thanks for the preceeding analysis of ammonia as a general purpose
    transport fuel.

    I'd not previously heard anything about it, pro or con, until a piece on Radio 4 mentioned it as a likely minimally polluting fuel for container ships,
    so it seemed logical to consider if ot would also work for aircraft: the answer seems to be 'yes'.

    Well, i did consider that, but then looked again

    Energy density is OK, but what sort of engine will run it?

    Now they were talking about fuel cells, and fuel
    cells=>electricity=>electric motors=> ducted fans or propellors is not massively efficient at higher powers and its all a bit heavy.

    And that s as I see it the issue with ammonia. Its got the energy
    density and its easy to synthesise and it doesn't need scarce carbon
    dioxide to make it and it can use atmospheric oxygen to create power so
    that doesn't need to be carried by the plane.

    BUT if you run it in a fuel cell its gonna be heavy and inefficient, and
    if you throw it in to burn in a gas turbine, well the chances of NOx
    production are fairly high.

    Its already a concern in jet engines, and with nitrogen in the fuel
    itself you are going to have to smack a lot more nitrogen through the
    engine for a given power level

    There are no easy answers or we would already be using them.

    As I said, for ships - large ones - the obvious answer is small lifetime fuelled sealed nuclear reactors.

    For aircraft? Ive not been able to construct a realistic scenario for >
    1 hour duration other than hydrocarbon fuel. Just possibly lithium air batteries.

    As far as Radio 4 goes, well I grew up with the home service but I don't
    listen any more.

    The world they seem to live in is like a distant roseate childhood
    dream. It has no relation to the reality of my life in the real world of technology.






    --
    “I know that most men, including those at ease with problems of the greatest complexity, can seldom accept even the simplest and most
    obvious truth if it be such as would oblige them to admit the falsity of conclusions which they have delighted in explaining to colleagues, which
    they have proudly taught to others, and which they have woven, thread by thread, into the fabric of their lives.”

    ― Leo Tolstoy
    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)