MicroPython Forum

So I made some further tests: Using the previous version for machine.uart does not change the picture a lot. The crashes and lock-ups occur too. Only I have not seen the character doubling. So the latter seems just one variant of misbehavior caused by the underlying bug in threading. Nevertheless I ...

Esptool just copies data to the flash memory and does not care about the type of the data.

You can try to use a single thread only with sufficiently large transfer buffers. If that does not fit, I could make a firmware version with the previous version of uart.write().

It seems to depend on the code size as well. With a minimal code I see no error. If I just add some non-executed code lines, I get errors. So there seems to be something fundamentally wrong with threading and interrupts.

When enabling threading I see all kinds of errors, very rarely character doubling, more often just lock-up of the sending thread, or sending completely wrong data. So there seems to be a general issue or challenge with threads and interrupt. Maybe a stack overrun. It does not matter in which thread ...

Not good. The erorr I had seen disappeared with that change. But it also disappeared with setting timeout. About your set-up and threads: - in which thread is the UART communication placed? - can you try to run the UART test with only thread0 active? Edit: I could replicate the bug when the UART sen...

OK. Sending frequent was the trigger. If I do that, I see errors too. Not doubling, but gaps. These should not occur either.

Can you try this firmware version: https://github.com/robert-hh/Shared-Stu ... rmware.uf2

Simple logic analyzer: https://www.amazon.de/AZDelivery-%E2%AD%90%E2%AD%90%E2%AD%90%E2%AD%90%E2%AD%90-Logic-Analyzer-gratis/dp/B01MUFRHQ2/ref=sr_1_5?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=1WTMPVMIYNS55&dchild=1&keywords=logic+analyzer&qid=1618500108&sprefix=logic+%2Caps%2C180&sr=8-5 Good fo...

Do you use threading in your code?

No worries. I just wanted to be sure. And the report of the UART setting could indeed reflect the way it is set. But still I cannot replicate that, even if I send at two lines. Do you have the option to connect a logic analyzer, or just a UART/USB bridge to a PC for verification, that indeed double ...