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Recommendation of MCU for industrial device

Posted: Fri Aug 23, 2019 7:12 pm
by urielka
Hi,

We are planning on building an industrial device(meaning 24/7 operation with temperatures between - 40 to 80C) which will use Micropython on an MCU as its "brain".

We want an MCU with ethernet and usb but we might just go with an external chip for ethernet.

We were thinking on using the MCU of the pyboard 1.1 because we assume it will be the most supported.

Is there a specific MCU which is recommended and will be supported by micropython in the long term? Are the other boards specified in the wiki feature wise similar to pyboard?

Re: Recommendation of MCU for industrial device

Posted: Fri Aug 23, 2019 11:16 pm
by hlovatt
We are using PyBoard 1.1 and a WIZnet for ethernet.

Re: Recommendation of MCU for industrial device

Posted: Sat Aug 24, 2019 2:45 am
by jimmo
The stm32 and particularly the f4 and f7 series are the best supported, mostly because that's what's in the pyboards.

The f767 (from the pyboard-d sf6) includes an ethernet mac. I am aware of people using this (with MicroPython) for commercial applications. (i.e. literally using the sf6 module via the wbus connector, just adding the magnetics and rj45 to their board).

Re: Recommendation of MCU for industrial device

Posted: Sat Aug 24, 2019 5:32 am
by pythoncoder
@urielka The temperature range is very demanding especially at the low end - I'd check component availability of all parts at the start of any proposed design. In the mechanical design consider condensation when temperature rises from a low value.

Apologies if this is familiar to you.

Re: Recommendation of MCU for industrial device

Posted: Tue Sep 03, 2019 6:27 am
by mcauser
The ST docs list the pyboard's STM32F405RGT6 temperature range as -40 to 85 deg C.
https://www.st.com/content/st_com/en/pr ... 405rg.html

The 3 new Pyboard D-series, SF2W (STM32F722IEK), SF3W (STM32F723IEK) and SF6W (STM32F767VIT) each are -40 to 105 deg C.

Re: Recommendation of MCU for industrial device

Posted: Tue Sep 03, 2019 7:18 am
by pythoncoder
Things have evidently moved on since I designed for wide temperature range when it required expensive military grade components throughout.

The issue of condensation won't have gone away, though. At -40C everything becomes covered in ice which melts as it warms up. Dealing with it requires either hermetic sealing or potting, with the latter having implications for thermal management.

Then there's testing. Recalls countless hours testing prototypes in an environmental chamber...