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Thread: Automotive grade Teensy

  1. #1

    Automotive grade Teensy

    I was wondering if an Automotive Grade Teensy will ever be released for more demanding environments.

    We are thinking about using a Teensy for a small satellite and we need a greater temperature range than offered by the standard part.

  2. #2
    Senior Member+ Theremingenieur's Avatar
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    Basically, and since the schematics and BOM of the Teensy are open source, you are free to re-create it with the automotive grade variants of the components if these are available from the manufacturers.

  3. #3
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    I'm using a Teensy 3.5 for automotive use. I suggest you don't use buck converters and just go straight to a voltage stabilizer that survives cranking while maintaining steady voltage, the one I use works between 8-40 V input, and 5v 30A is output.

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    From prior posts on potential Teensy cubsesats the main component limiting temperature is the crystal operating out of spec. If your code can handle slight delta in clock rate you can probably use the a base teensy out to the temperature range of the MCU.

    Otherwise you are potentially using a custom PCB and work out a crystal/clock solution that can perform across your temperature range to your spec, which potentially you want to do for weight reasons in any case given you will not be using the USB bootloading hardware post launch.

    Anecdotally Teensy seem to handle vacuum fine, and have survived high altitude ballooning.

  5. #5
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    yup, and we get -20 temps here in winter, still running with t3.5 , and boiling temps in summer

  6. #6
    First, remember that temperature rating means that the manufacturer guarantees operation within that range, but the part may very well operate just fine outside that range. There are components with relatively low hard limits (aluminium caps, batteries, etc.) while other components can operate just fine over a much wider range. So I'd say get a temperature chamber and test your product in there.

    And if you want to operate your Teensy at a very low temperature, you could just use some a heater. It will use some electricity (might be an issue on a satellite) but it works.

    You could also insulate it, but then you may also need to provide a cooler (i.e. Peltier) for high temperature operation. Solid state thermoelectric devices are nice because they can do both cooling and heating.

  7. #7
    Quote Originally Posted by Theremingenieur View Post
    Basically, and since the schematics and BOM of the Teensy are open source, you are free to re-create it with the automotive grade variants of the components if these are available from the manufacturers.
    But the firmware (bootloader) isn't, AFAIK.

  8. #8
    Senior Member+ Theremingenieur's Avatar
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    Yes, but the firmware is neither temperature nor humidity dependent...

  9. #9
    Senior Member+ defragster's Avatar
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    Also - the Bootloader doesn't really come into play except when the button is pressed or during programming - those are not active under operational conditions.

    The resident firmware will run according to design specs - and is created by the programmer using the above noted open/available source code. Where the programmer has access to that and all hardware features such as watchdog or other needed device features to conform to the process requirements.

  10. #10
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    Also keep in mind that, if you create a custom teensy PCB, you can move the bootloader chip to an external (non-automotive) programmer PCB. Maybe not a nice move towards Paul, but as far as I remember, he repeatedly clarified that he doesn't have a problem with that. That might have changed, though - I don't know.

  11. #11
    Senior Member PaulStoffregen's Avatar
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    Quote Originally Posted by bigpilot View Post
    But the firmware (bootloader) isn't, AFAIK.
    Maybe you should double check NXP's documentation. The bootloader chip (MKL02Z32VFG4) is indeed rated for -40 to +105 C temperature.

    https://www.nxp.com/docs/en/data-she...2P32M48SF0.pdf

  12. #12
    Senior Member PaulStoffregen's Avatar
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    Also notice the footnote on page 17, saying up to 125 C temperature is allowed if power dissipation is low. The bootloader does indeed remain in a very low power state, except when uploading new code, and typically uploads are done within a few seconds. How close you could push to 125 C is a good question, but at least this footnote in NXP's datasheet and the very low power modes used by the bootloader should give some extra temperature range above 105 C. Well, at least as far as the boot loader chip is concerned. The rest of your custom PCB is up to you!

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