It is aimed to build CANBus communication between two Raspberry Pi boards. This setup is accomplished with the Microchip's stand-alone MCP2515 CAN controller.
1 RaspberryPi 3 Model B+ (Raspi1)
1 RaspberryPi 3 Model B v1.2 (Raspi2)
2 MCP2515 CAN Bus Module TJA1050 Receiver SPI (CanModule1, CanModule2)
Environmental Setup
Raspi1 --(SPIcomm)-- CanModule1 ==<CANbus H,L>== CanModule2 --(SPIComm)-- Raspi2
MCP2515 Note: Modification is required! Since TJA1050 CAN Transciver operates at 4.75V~5.25V (Typically @5V), it is necessary to add Vdd 5V input pin to the module besides Vcc 3.3V. It is explained how the MCP2515 CAN module is adjusted below along with the pictures.
1.MCP2515 CANBus Module
2.Find the Vcc trace for TJA1050
3.Cut the copper trace to replace with 5V
4.Scrape the insulator to make soldering over the trace.
5.Solder the jumper wire
6.Put some silicon to strength the connection
7.I preferably replace the 7 pin male headers with 8 pin Male PCB Mounting Right Angle connector
8.Overall board with modification
Download Updates:
sudo apt-get update
sudo apt-get upgrade
sudo reboot
Enable SPI:
Applications Menu --> Preferences --> Raspberry Pi Configuration --> Interfaces --> Select SPI Enabled
OR
sudo raspi-config
5 Interfacing Options --> P4 SPI --> Yes --> The SPI interface is enabled --> Finish
Check Kernel version:
uname -a
Linux raspberrypi 4.19.42-v7+ 1219 SMP Tue May 14 21:20:58 BST 2019 armv71 GNU/Linux
Modify config.txt:
For later kernels (4.4.x onwards)
sudo nano /boot/config.txt
Add the following setup at the end of the file:
dtparam=spi=on
dtoverlay=mcp2515-can0,oscillator=8000000,interrupt=25
dtoverlay=spi-bcm2835
dtoverlay=spi-dma
Save: CTRL + X --> Enter
sudo reboot
Install Can-utils:
sudo apt-get install autoconf autogen
sudo apt-get install libtool
git clone https://github.com/linux-can/can-utils.git
cd can-utils
./autogen.sh
./configure
make
sudo make install
sudo apt-get install can-utils
sudo reboot
can0 Availability Check
Full circuit wiring must be completed before checking the related folder. And do not miss having common ground, since there is not any additional GND pin for Can transmission lines (CAN_H, CAN_L).
sys --> bus --> spi --> devices --> spi0.0 --> net --> can0
OR
If there is not can0 folder in the specified directory, check config.txt and ensure that:ls /sys/bus/spi/devices/spi0.0/net
dtparam=spi=on
dtoverlay=mcp2515-can0,oscillator=8000000,interrupt=25
dtoverlay=spi-bcm2835
dtoverlay=spi-dma
AND check the connections in the circuit.
Test: Sending data from RasPi1 to RasPi2
RasPi1
sudo ip link set can0 up type can bitrate 500000
cansend can0 100#12FF34AA56DD66
Raspi2
sudo ip link set can0 up type can bitrate 500000
candump can0
RaspberryPi 3 Model B+
https://en.wikipedia.org/wiki/Raspberry_Pi
https://pinout.xyz/
MCP2515 Can Controller
https://www.microchip.com/wwwproducts/en/en010406
http://ww1.microchip.com/downloads/en/DeviceDoc/MCP2515-Stand-Alone-CAN-Controller-with-SPI-20001801J.pdf
https://www.nxp.com/docs/en/data-sheet/TJA1050.pdf