Can't set 33.3kbps baudrate about arduino-can

[mister0wl]

As my post generated a rather moderate interest, I tried hard to do my homework. I'm very grateful as I could learn a lot. :) However, this is a bad news for all of us. Since the BTR0 register only allows 6 bits for setting up BRP, it is impossible to set up frequencies below 50kbps because the ESP32 CAN bus controller (SJA1000 compatible) clock frequency is bound to the ESP32's APB clock frequency that is 80MHz. As the biggest BRP value could be only 0x3f, this renders any baudrates below "50E3" impossible.

This is a limitation of the hardware, not the library, but there's no point for 40E3, 20E3 and 10E3, in fact this is misleading as it looks like it supports CANopen however it isn't. I propose to remove those branches in the switch baudrate section in ESP32SJA1000.cpp and mention this somewhere in the code.

Pls also see https://esp32.com/viewtopic.php?t=2142

Cheers!

[sandeepmistry]

I propose to remove those branches in the switch baudrate section in ESP32SJA1000.cpp and mention this somewhere in the code.

@mister0wl would you like to make a pull request for this suggestion?

[mister0wl]

Well... I'm still learning Github but I'll try. Thanks!

[sandeepmistry]

Closed via #17.

[ale1800]

Hi, I'm trying to do an obd reader with your same hardware (esp+sn65vh230) but I'm finding some difficulties to write right code. Im trying the examples but no one works. Could you please share yours? thanks in advance

[zalexzperez]

@mister0wl
I'm trying to use your forked version.
I also need to use the baudrate at 33.3kbps with a newer ESP32 devkitc V4

What are the modifyRegister correct values?

Thanks!