F103 CAN baud rate

Question

F103 CAN baud rate

Closed this issue 3 years ago · 10 comments

Steps to reproduce:
no real WBO hardware needed, blue pull and logic analyzer should be enough (?)

cd firmware
make -j12 BOARD=f1_dave

before 8603450 we had

Answer 1 · 2022-01-13T21:14:37.000Z

after 8603450 we have

Answer 2 · 2022-01-13T21:16:17.000Z

@blundar great news HW works with 250K version of FW

Answer 3 · 2022-01-13T23:29:17.000Z

mck1117 commented 3 years ago

Answer 4 · 2022-01-13T23:36:13.000Z

I cannot explain it i just report my test results sorry

Answer 5 · 2022-01-23T23:43:37.000Z

Just to confirm - is it OK to test with a blue pill with logic analyzer?

Answer 6 · 2022-01-24T00:40:58.000Z

don't you need some other devices on the bus?

Answer 7 · 2022-01-24T00:51:33.000Z

@thirstyone please consider using more words. We are trying to discuss pretty complex issues here and in my opinion short form is not effective. If you are looking to help please consider typing a bit more words to spell things out a bit more explicitly.

@thirstyone stm32 uses TTL levels on RX and TX pins right? Are you saying that without a real transceiver and without loopback I would never see CAN peripheral TTLing anything readable?

Answer 8 · 2022-01-24T01:59:29.000Z

without loopback I would never see CAN peripheral TTLing anything readable?

tie TX and RX together, with a 1k pullup to 3.3v, you don't need a CAN tranciever, but you may need a "bus" enough to fake it.

Answer 9 · 2022-01-24T02:17:38.000Z

@thirstyone thank you - with real bus I got 8MHz F103 to work! (alligator clips are wired to CANHacker with 120R)

Answer 10 · 2022-01-24T02:20:50.000Z

and F103 WBO firmware CAN works as well as is on this blue pill setup, I have no idea what was wrong with my previous experiments on real WBO board