Electronic Cats' Flipper Add-On Sniffs, Sends, and Logs CAN Bus Packets
Attach this MCP2515-based add-on to a Flipper, install the app, and start analyzing (or sending) CAN bus traffic from the palm of your hand.
The Flipper Zero is a versatile electronics hardware multi-tool, best known for its wireless capabilities due to its built-in Sub-GHZ radio. In addition, it has an expansion port for add-ons. Electronic Cats took advantage of this feature by introducing the first Flipper CAN bus add-on board. Using this inexpensive adapter, you can sniff, send, and log CAN packets with a tool in the palm of your hand.
The add-on board has header pins that plug into the Flipper's expansion port. The other hardware is a screw terminal to connect wires to a bus and an IC. The Microchip MCP2515 is a standalone CAN controller with an SPI interface — which is how it communicates with the Flipper. This chip supports CAN version 2.0B but does not support the faster CAN FD (Flexible Data Rate.) However, CAN FD devices are generally backward compatible with 2.0-, 2.0A-, and 2.0B-based devices.
Adding the hardware alone is insufficient to do something useful with the Flipper Zero. That's why Electronic Cats developed an open source MCP2515 CAN bus app to support the add-on. It enables the Flipper to send or sniff packets on the CAN bus. It can also log packets to Flipper's microSD card and from an address for a specific device on the bus.
Electronic Cats published a step-by-step tutorial on installing and using the MCP2515 CAN bus app. To run this app, you will need the Unleashed firmware. Unleashed is a fork of the official firmware that unlocks much more functionality than a stock Flipper. Switching to Unleashed is straightforward when using its associated web-based installer tool. That same tool lets you go back to stock at any time.
The add-on and app are open source. You can download the design files from this GitHub repository. You can also help Electronic Cats develop other devices by purchasing an assembled CAN bus Flipper add-on from their online store. The board is regularly priced at $15 but is currently on sale for $10.