User Guide: Troubleshooting - d-ronin/dRonin GitHub Wiki

Panic Codes

If a board fails to boot, it will often flash a panic code on the error LED. The meaning of these is given below. Unfortunately OpenPilot boards (e.g. Revolution) do not have an error LED.

LED Flashes	Error
2	IMU initialization error
3	Magnetometer initialization error
4	Barometer initialization error
5	Flash initialization error
6	Filesystem initialization error
7	Internal I2C bus initialization error
8	External I2C bus initialization error
9	SPI bus initialization error
10	CAN bus initialization error
11	ADC initialization error

Note: This table is only valid for Tanto release and later