MCP2515 with Arduino Uno receiving data only once in a bluemoon

Projects Networking, Protocols, and Devices
1

Hey guys, been trying to figure this out for the past few days. I'm using an MCP2515 paired with an uno and wired as follows

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When using the cory fowler library and the autowp library I've only ever managed to successfully receive data the first time on each library.

I've tried changing the CS pin, input pin, swapped the CAN HIGH and CAN LOW around to no avail, after the first run, it simply just doesn't receive anymore. I know the pins are receiving something as I've poked around with a multimeter and they're definitely getting voltage.

All I'm trying to do is listen to the data and display some information, not even trying to send data back please help :sob: :sob:

2

Assuming you are using the OBD2 port, in OBD2_PID_Request.ino change the MCP_16MHZ to MCP_8MHZ.

3

I'm actually not using the OBD2 port, I am using an Ali Express HVAC control unit that has can bus for it to display and control from an android headunit.

I am also using MCP_8MHz as the MCP2515 has a 8MHz crystal on it

4

Understood.
Is the HVAC in a car?

If so, then use the OBD2 port as piece of test equipment to prove that your adaptor & Arduino combination is working correctly. The goal is just to prove that communication is possible.

Once you have successfully completed that step you can go back to the task of trying to monitor the HVAC.

5

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