Pololu Simple - Manual (Page 22)

3.5. LED Feedback
The Simple Motor Controllers have three indicator LEDs that provide feedback about the current state of the
controller. The LEDs can tell you whether an error is occurring, whether the USB connection is active, what direction
the motor is driving, and much more.
Simple Motor Controller 18v7 LEDs.
Simple High-Power Motor Controller 18v15 or 24v12
LEDs.
Simple High-Power Motor Controller 18v25 or 24v23
LEDs.
The Simple Motor Controllers have three indicator LEDs:
Pololu Simple Motor Controller User's Guide © 2001–2014 Pololu Corporation
3. Getting Started Page 22 of 101