CAN
This section introduces how to use the CAN interface function on the Raspberry Pi, laying the foundation for subsequent project development.
Enable Interface Configuration
- Enable the CAN interface (disabled by default)
- Edit the config.txt file
sudo nano /boot/firmware/config.txt
- To use CAN, add the following lines:
dtoverlay=spi1-1csdtoverlay=mcp2515,spi1-0,oscillator=16000000,interrupt=17
- After modification, reboot the Raspberry Pi to use the CAN driver normally:
sudo reboot
- After reboot, use the following command to check the relevant ports; you should see a CAN port:
ifconfig
- If the CAN port is DOWN, bring it up (here the device is identified as can0, so the command uses can0; the final 500000 parameter is the CAN bus baud rate in bit/s):
sudo ip link set can0 up type can bitrate 500000
- If the CAN port is DOWN, bring it up (here the device is identified as can0, so the command uses can0; the final 500000 parameter is the CAN bus baud rate in bit/s):
- You can also check the relevant devices in the SPI subsystem:
dmesg | grep spi
Usage
- Install tools:
sudo apt updatesudo apt-get install can-utils
- Send data using cansend (send 0x11 0x22 0x33 0x44; here the hardware is identified as can0, so the command uses can0):
cansend can0 000#11.22.33.44
- Listen for CAN data frames using candump (here the device is identified as can0, so the command uses can0):
candump can0