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Thread: Teensy 3.5 temperature range

  1. #1

    Teensy 3.5 temperature range

    Hi,

    I would like to use the Teensy 3.5 in an industrial automation project but I am worried that the bottom end of the temperature range (I need to be able to go down to -40 C).

    I have read some threads on this forum about the 3.0/3.2 being used in low temperatures as long as the crystal is replaced:
    https://forum.pjrc.com/threads/23752...ll=1#post32053
    and:
    https://forum.pjrc.com/threads/33525-Temperature-rating


    Is the crystal the limiting factor on the 3.5 as well?

    Thanks



    edit:
    Just saw the sticky about posting in the general guidance section if no wires have been run yet, rookie mistake I suppose.

    I will repost there, apologies

  2. #2
    Senior Member brtaylor's Avatar
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    At least the processor and bootloader are rated for -40C; both the MK64FX512VMD12 and MKL02Z32 are -40C to 105C temperature rated. So you could roll your own Teensy 3.5 hardware design that is compatible with Teensy software.

  3. #3
    Thanks for the information!

    I plan on putting the eventual controller into a commercial product and am worried about making my own because I read on this forum that Teensy clones are not allowed (which I completely understand). If I use those two chips and add the other things I need in the circuit (which would include an RTC and a SD card), would I not kinda be making a clone? I guess I'm not sure how close you can get without breaking that rule.

  4. #4
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    You could simply purchase the companion chip (MKL02/04) from PJRC, preloaded with their special firmware.
    This way, you can design your own Teensy-compatibile board without issues.

  5. #5
    Senior Member brtaylor's Avatar
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    Yes, I've used the PJRC MKL02 for several projects where I needed to meet specific temperature ranges or access to pins not available on the Teensy board. It's allowed by PJRC and one of the great ways they support their products.

  6. #6
    Senior Member
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    Concur with XFer and brtaylor.

    Based on several HALT series done with Teensy 3.2s, do not recommend use in industrial control products where internal ambient is under -20C.

    As 'industrial' grade stuff is typically not limited to battery power, can use stock Teensy boards by parking a Dale (heater) resistor next to the Teensy board. This simple approach has worked for me in a controller scoped for a dairy farm environment, but there may be additional fail-safe requirements where human safety can be affected.

  7. #7
    Thanks very much again (to all) for the information.

    I feel like "rolling my own" Teensy setup is a little over my head at the moment, although this may be a good excuse to learn. From the schematic it doesn't look too difficult, but I probably don't know enough to say that it will be easy or hard. There are Arduino closes that have been redone to have a temp limit of -40, perhaps I will stick with that for the time being, and consider making a my own teensy version in the future.

    Thanks again for the answers

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