CAN Bus

IoT-Bus CAN Bus

Buy it here. 

This IoT-Bus module provides a CAN bus transceiver that takes advantage of the built-in CAN bus controller in the ESP32. You will need either an IoT-Bus Io or IoT-Bus Proteus processor board. It can also be used with any ESP32 module that makes pin 4 and 5 available.

CAN Bus Termination

The board provides the ability to terminate with a 120 ohm resistor. If you are using two boards back to back you will need to terminate. This simply requires a solder blob between the terminate pins on board. Typically speeds up to 250K will work without termination. Above that it is essential.