Adding RTR ID

[paulmac00]

The library is working great, however I am struggling with adding an RTR tag to the CAN ID.

Is anyone able to provide a quick pointer? I've been searching the interwebs for the past 3 hours or so

Thank you!

[jxltom]

I have a demo here for different kind of message https://github.com/jxltom/micropython-mcp2515/blob/master/demo.py, though it is written in python

[paulmac00]

Hey JX,

Thanks for the quick response! Any help is very much appreciated.

I found where you added the RTX tag:
rtr_frame = CANFrame(can_id=0x7FF | CAN_RTR_FLAG)

I'm working on an arduino so I've written:
frame.can_id = 0x4a | MCP2515::CAN_RTR_BITMASK;

I also look into MCP2515_Const.h where it is defined as
static uint32_t constexpr CAN_RTR_BITMASK = 0x40000000;

However it doesn't seem to be working properly. I'll play around with it tomorrow and see if I can make some more progress.

[jxltom]

Can you receive the standard frames? If so, please check the configuration of your RXB. You need to enable it to receive extended frames by RXBnCTRL_RXM_STDEXT or just disabled the filters/masks.

[paulmac00]

Hey JX,

Can you receive the standard frames?
Yes, I can receive and send standard frames. I will look into the RXB config today.

I've taken a look at it and I think my problem is I can't work out how to add to the CAN_ID frame. Any tips for arudino?

[fkaraokur]

I'm having trouble here too. Can you explain what he said?