Arduino CAN bus sketch

This sketch reads CAN data using a CAN bus shield (or any MCP2515 based boards) and outputs it over the serial interface.

It requires the CAN bus shield library from Seeedstudio.

You can use this Python script I wrote to display the data in a more readable format.

Configuration

Make sure the variables at the top of the sketch are correct for your usage.

• CS_PIN should be set to the chip select pin for your board (leave to 9 if you have the latest CAN Shield from Seeedstudio)
• SERIAL_SPEED is the speed of the serial interface. Make sure it matches the settings of whatever software you're using to read the data
• CAN_SPEED should be set to the speed of the CAN bus you're connected too (possible values).

Be careful, setting the wrong speed can mess with the CAN bus. I once set the wrong speed when connecting it to my car and my dashboard lights went crazy! Restarting the car solved the problem, but in any case, use at your own risk.

If you're not using Seeedstudio's shield you may have to tweak the library to make it work. I had another MCP2515 board and could not make it work with Seeedstudio's library. This was due to the oscillator's frequency. Seeedstudio's shield uses a 16Mhz oscillator, whereas some boards use 10Mhz or some other value. So you need to use Kvaser's bit timing calculator and change the CFG1, CFG2 and CFG3 variables for your bus speed near the bottom of mcp_can_dfs.h.