ESP32 OBD-II Emulator

Open-source OBD-II emulator based on an ESP32 + CAN transceiver IC, controllable via WiFi through a simple web UI (or via API).

Supported protocols

• ISO 15765-4 CAN (11 bit, 500 Kbps)

Supported modes & PIDs

Mode	PID	Description
0x01	0x0C	RPM
0x01	0x0D	Vehicle speed
0x01	0x11	Throttle position
0x09	0x02	Vehicle Identification Number (VIN)

Usage

1. Connect to the WiFi network ESP32-OBD2 (with password 88888888)
2. Navigate to 192.168.4.1
3. Enjoy :)

Hardware

• ESP32-WROOM-32
• SN65HVD230 (or any other CAN transceiver IC)
• Serial->USB adapter
• Power supply (3.3V)

Connections

• IO 4 -> CAN RX
• IO 5 -> CAN TX

Flash / Install (via esptool)

1. Download the latest release binaries
2. Flash (app, bootloader, FAT filesystem): esptool.py write_flash --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 bootloader.bin 0x10000 obd2-emu.bin 0x8000 partitions.bin 0x110000 fatfs_image.img

Build

1. Install the Espressif IoT Development Framework
2. Clone this repo: git clone ...
3. (Optional) Configure: make menuconfig
4. Build: make all
5. Flash: make flash
6. Build & flash FAT image: make flashfatfs

Note: You might want to change some config values, for example: serial flasher, baud rate, pins, etc.

API

PATCH /api/vehicle

• Content-Type: x-www-form-urlencoded
• Data:
  • name
    • speed
    • rpm
    • throttle
    • vin
  • value
• Example (CURL): curl -XPATCH -H 'Content-Type: application/x-www-form-urlencoded' -d 'name=speed&value=50' '/api/vehicle'

Acknowledgements

• ESP32-CAN-Driver
• ESP32_makefatfs
• esp32-http-server
• Espressif IoT Development Framework
• OBDSim