MicroPython Forum (Archive)

In general, my opinion is that ST devices are more robust and reliable. Further, the MicroPython port is more mature than on the ESP32.

That said, I'd still consider the ESP32 range - particularly if I needed wifi and the system wasn't super-critical. I would just allow more time to fix issues if they arose.

mattyt wrote: ↑

Sun Feb 20, 2022 7:15 am

In general, my opinion is that ST devices are more robust and reliable. Further, the MicroPython port is more mature than on the ESP32.

That said, I'd still consider the ESP32 range - particularly if I needed wifi and the system wasn't super-critical. I would just allow more time to fix issues if they arose.

Thanks good to know.

I'm planning to use the ESP32-S2 chip in a remote installation (offshore) running micropython. Is this crazy, should I look at moving to ST? Don't need wifi.

hi,

the subject is very complex. I work in the electronics industry in France. The products we design have to be
CE marking (electromagnetic compatibility EMC, technical documentation ...)

Then for the security market, the devices have certifications: (hardware)
ATEX
IECEX
CSA
...

For example, in France (in the security market), it would be very difficult to sell an ESP32 development board without CE marking. Moreover the temperature range in the industrial market is -40°C +85°C
The first problem is hardware, the Second: is Micropython ready for industry?

YES but not for all markets

I notice that more and more markets require SIL certification (Safety Integrity level IEC 61508). The ZEPHYR project is preparing for this : https://www.zephyrproject.org/zephyr-pr ... ng-system/
I know that ST sells pre-certified SIL libraries.

But I don't know if Micropython can be SIL ? To be SIL it is rules of development (cycle in V) but it seems to me that the standard recommends languages and I do not know if python is part of it.

For your project, the only board (that I know) that offers industrial temperature range is the PORTENTA board but be careful it is sold as a development board so without CE mark (the CE mark is only for Europe of course)

Thank you,

Interesting thanks!

We are currently going through IECEX testing/certification with our device. It will be used in T4 so temperature up to 135C. We aren't using any development boards, we have a custom pcb with ESP32S2 chip + flash + psram.

135°C! I'm amazed you can get components qualified to above 100°C. Are they widely available?

A long time ago I worked on development of radio transmitters for rockets - the temperature range was -55°C to +100. That was hard enough

pythoncoder wrote: ↑

Mon Feb 21, 2022 9:50 am

135°C! I'm amazed you can get components qualified to above 100°C. Are they widely available?

A long time ago I worked on development of radio transmitters for rockets - the temperature range was -55°C to +100. That was hard enough

Luckily the equipment doesn't need to operate at that temperature, the 135 is the maximum allowable surface temperature under fault conditions. So for example acetaldehyde ignites at 140 so for T4 classification you need to design your device so that after an infinite numbers of faults are considered, the device will not go over 135. So if you have a 3.6V battery connected to an ESP32 and the ESP32 IC fails internally to a short circuit, 50A+ will flow through the circuit, lots of heat and boom. Lots of fuses, resistors, diodes and encapsulation in the design process. I have been working on one device since august 2021 and I reckon I'm only 1/2 way through the hoops

Your design is intrinsically safe ! Well done

good luck for the continuation and for the certifications

P@T wrote: ↑

Mon Feb 21, 2022 7:50 pm

Your design is intrinsically safe ! Well done

good luck for the continuation and for the certifications

Thanks I'll need it!

@p_j Thanks for that - interesting. Way outside of my experience

Hi

The problem in the industry is that certifications require a lot of time in documentation and it's boring.

One thing I have seen in esp32 is that its ADC is not very good :
Thank you