Hardware Selection
Supported Boards
| Board | CAN Interface | Library | Status |
|---|---|---|---|
| Adafruit Feather RP2040 CAN | MCP2515 over SPI | mcp2515.h (autowp) | Tested |
| Adafruit Feather M4 CAN Express (ATSAME51) | Native MCAN peripheral | Adafruit_CAN (CANSAME5x) | Tested |
| ESP32 with CAN transceiver (e.g. ESP32-DevKitC + SN65HVD230) | Native TWAI peripheral | ESP-IDF driver/twai.h | Tested |
| M5Stack Atomic CAN Base | CA-IS3050G over ESP32 TWAI | ESP32 TWAI | Tested |
| Adafruit ESP32 Feather V2 + CAN Bus Featherwing | MCP2515 over SPI | mcp2515.h (autowp) | Tested |
Supported Vehicle Variants
Select your vehicle hardware variant via the #define directive in sketch_config.h.
| Define | Target | Listens on CAN IDs | Notes |
|---|---|---|---|
LEGACY | HW3 Retrofit | 1006, 69 | Sets FSD enable bit and speed profile control via follow distance |
HW3 | HW3 vehicles | 1016, 1021 | Same functionality as legacy |
HW4 | HW4 vehicles | 1016, 1021 | Extended speed-profile range (5 levels) |
note
HW4 vehicles on firmware 2026.2.9.X are on FSD v14. However, versions on the 2026.8.X branch are still on FSD v13. If your vehicle is running FSD v13 (including the 2026.8.X branch or anything older than 2026.2.9), compile with HW3 even if your vehicle has HW4 hardware.
How to Determine Your Hardware Variant
- Legacy — Your vehicle has a portrait-oriented center screen and HW3. This applies to older (pre Palladium) Model S and Model X vehicles that originally came with or were retrofitted with HW3.
- HW3 — Your vehicle has a landscape-oriented center screen and HW3. You can check your hardware version under Controls > Software > Additional Vehicle Information on the vehicle's touchscreen.
- HW4 — Same as above, but the Additional Vehicle Information screen shows HW4.
Hardware Requirements
- One of the supported boards listed above
- CAN bus connection to the vehicle (500 kbit/s)
important
Cut the onboard 120 Ohm termination resistor on the Feather CAN board (jumper labeled TERM on RP2040, Trm on M4). If using an ESP32 with an external transceiver that has a termination resistor, remove or disable it as well. The vehicle's CAN bus already has its own termination, and adding a second resistor will cause communication errors.
Which Board Should I Choose?
- Feather RP2040 CAN — Most popular choice, well-documented, 3D printable case available
- Feather M4 CAN Express — Native CAN controller (no SPI overhead), slightly faster
- ESP32 + CAN transceiver — Cheapest option if you already have an ESP32, requires external transceiver module
- M5Stack Atomic CAN Base — Most compact form factor
- Feather V2 + FeatherWing — WiFi-capable ESP32 with MCP2515 CAN controller, good balance of features and cost