The CAN32—an ESP32-Based CAN Bus Board

While the Internet of Things has its roots in the web architectures of the dot-com boom, the Industrial Internet stems back to the SCADA systems, networked industrial control systems, of the early sixties.

Unlike the Internet, which is pretty much defined by ubiquity of the TCP/IP protocol stack, SCADA systems use a number of different protocols some of which are more common than others. For vehicles the most commonly used protocol is called Controller Area Network, normally known as CAN bus.

Linking CAN bus systems to the Internet has become more and more trivial over the last couple of years, especially with cheap WiFi-connected ODB-II adaptors becoming available. But sometimes you want to talk directly to the CAN bus and that’s where something like the new CAN32 board comes in.

The CAN32 development board is based around an Espressif ESP32-Wroom module, which provides both WiFi and BLE, and uses the Silicon Labs CP2102N for USB to UART connectivity, while the CAN bus connectivity is provided by the TI SN65HVD230DR transceiver chip with four larger vias allow connection of CAN H, L, 12V, and GND. The board also has a micro SD card slot, and a 15V regulator. That means it can be powered via USB, or directly via the vehicle battery 12V (max. 15V).

Software to support the CAN bus protocol on the ESP32 is still under active development, but there are working example code available on GitHub.

The CAN32 board isn’t the first ESP32-based CAN bus board I’ve come across, there have been others, however it is the most compact that I’ve seen. If you’re interested in picking one up it’s available on Tindie for $39.00 plus shipping.