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asez73

Member since Oct 2014 • Last active Jun 2017
  • 4 conversations
  • 115 comments

I have an Espruino board 1v4 and a Kickstarter Pico board...

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  • in Electronics
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    Well, they wrote it. I can't say about electrodragon, but some suppliers don't provide the certificates that goes with CE, FCC and more unusual ROHS.
    So far there is the :
    +Acorn V1 (They wrote it on the metallic radio shield but I 'd like to get the certificates)
    +WT8266-S1 which is available from aliexpress supplier's shop and has it's certificates
    ? AI-thinkers pretends it, but I have not read it.

    All the others have just copied the esp8266 chip statements (and the chips have their certificates) but never have anything written about their modules.
    The thing is that PCB's material and soldering joints should also be ROHS: that's never written actually. To be CE, in theory, you have to retest some part of the radio functionalities / power once it's in the final box...

    Olimex is clear about not beeing CE for instance. Although they are ROHS. It's probably because of the costs and the metallic shield required for radio.

    So, it's a quick summary.

  • in Electronics
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    Hi @Gordon,
    Very few esp modules do have a ce and rohs certifications.
    That's a problem as soon as you want to juild anything commercialy sellable in Europe.

  • in Electronics
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    @Gordon,
    Thank for your answer.
    About power saving, I suggest to use an ultra low quiescent current power regulator. I mean nA not ten's of nA.
    I am biaised toward 1 year autonomy on a pair of AA batteries and now considering Stm32l476 mcu. I would suggest to have a look at it's integrated capability to charge a super capacitor. Just to go on dreaming, power it from a cheap 1,5v solar panel such as those found in solar powered garden lights.
    May be that could be an optionnal shield, part of a new Kickstarter campain and, somewhere retrofit the Pico with it too...

  • in Electronics
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    Well, I found that power management is critical in iot...
    So, since the esp is not as power saving as it should be to use it on its own. I would suggest to carefully integrate the opportunity to switch completely off the esp from it's mcu fellow. And more or less let this mcu handle all of the io and realtime stuff before waking up the esp.
    That's just an opinion.

  • in News
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    Hi @Gordon, about this new board, would you open a separate thread? I think quite a number of suggestions could ne made.

  • in General
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    Hi @user6546,
    So, the port of Espruino to the Nucleo F401RE doesn't need the USB functionality mainly because it has an equivallent USB connection through the ST-Link v2 integrated one. This makes it an mbed compatible board.
    As a result, the USB port is under control of the ST-link and seen from Espruino's side as a serial port...

    The various difficulties, mentionned above, are just about flashing Espruino on a Nucleo board. They do not impact the functionnalities under Espruino.

    That said, it could be interesting to have the usb available on this board as it is OTG on the STM32F4.
    I think getting USB to work would need to break apart the ST-link board thus freeing the serial port used, design some accessory board providing the correct STM32F4 pins as well as a steady 5V power supply and the proper USB connector. Just to add, some HSI or LSI are provided by the ST-link part to the Nucleo, this is to consider too, specially for USB.
    On the Espruino interpreter side, you will have to reconfigure the serial link used with the ST-link part and let it behave as a USB port. The Pico is doing so but that's to be carefully studied as there is no bootloader in the Nucleo board port of Espruino.

    Quite a lot of work actually, specially compared to the Pico beeing readily available.

  • in Porting to new Devices
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    Just a link to start this port...

  • in Porting to new Devices
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    Hi, just a few arguments to this discussion:
    a- the global bill amounts to 25 - 30 euros! (box+sd+power supply+wifi dongle)
    b- running a rpi for month or years imply a bit of hardening on the linux side or you'll get sd wear: i have done than since 2 years now and finally openssl bugs imply reboots every 2 or 3 months
    c- power consumption is definitly not iot friendly: stm32L4 seems very interesting from this side (nA somewhere)
    d- no adc or dac on pi0
    e- single uart
    f- android tablets are getting as low as 30 euros

  • in General
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    Hi all,
    Just to mention that, on Ubuntu also, the Espruino interpreter for Nucleo needs the same modification to flash it from it's original binary file.
    The Nucleo's firmware has been updated to 2VJ25M13 and there is no improvement on this point so far.
    That is just set the 8th byte to 0x08 in Espruino's binary file.
    Then drag and drop it to your Nucleo device folder to flash.

  • in General
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    Hi, @Gordon!
    You are right!!!!
    I think most persons do not have a correct understanding of what is going under the curtain!
    I mean, doing really real time I/O in such a high level language as Espruino / JavaScript are, as simply as it is now, is quite a challenge very few of them would have tried, say using Arduino C++ approach!
    Furthermore we all try to do this on very small platforms, happily forgetting any realistic constraints of memory sizes or computation time/responsiveness.
    Espruino definitely allows to make it, reducing the source code to a minimal size.
    I think, just as every one else, I hit the available ram size wall.
    So, to make it concrete, I would state that any ram saving technique is good to use but, expecting a massive ram requirement reduction, is just an illusion. You have to choose an appropriate platform to your application!
    So, you are right when you consider that Espruino is targeted at small, very energy saving, platforms...
    Now it is clear that tomorrow will be brighter than yesterday... Maybe...
    It's a time/effort/cost alternative consideration.
    Should this community finds a clearly simple, universal, solution let's do it.
    I doubt...
    Go on!
    You know what you are doing as a software / hardware designer or architect. It's more than obvious looking at the Espruino's projects.

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