[Ovmsdev] MCP2515 driver bug?

[Craig Leres]

On 6/6/21 9:16 AM, Michael Balzer wrote:
> I've just found a spot-on post on this issue:
> 
> https://www.microchip.com/forums/tm.aspx?m=620741
> 
> Tom suggests implementing a state machine to reproduce the receive 
> order. His analysis & solution looks sound to me.

Leave it to chip designers to (a) identify issues with their 
implementations and (b) provide a features to work around the issues.

Poking around github, this rollver enabled driver might be a good reference:

     https://github.com/collin80/esp32_can/

Looks like it was added less than a year ago via this PR:

     https://github.com/collin80/esp32_can/pull/22

I'm using an (obsolete) chip for the J1850/Class B network in my 6th 
generation Corvette. I am using it with an atmega (running at 20 MHz) 
but the bus is only 10.4 kb/s and the part (HIP710) SPI master which 
precludes using SPI for anything else. I've been working on a J1850/CAN 
bridge so that ovms can access the bus; I had to step up to the 
atmega644/atmega1284 to pick up a second UART which can be used in SPI 
master mode for use with a MCP2515. But I haven't quite debugged my SPI2 
code...

		Craig