P4 Motor control: motor shield starts buzzing
First off, I am beginner and working my way through the Crow-projects of the Starter Kit De Luxe.
I followed the instructions of the "Motor Control' project (Project 4) correctly: Motor 1 on OUT 1 and 2, and Motor 2 on OUT 3 and 4. Additionally, I connected a 9V battery using the green power sockets (VIN, GND).
However the shield starts to buzz and flashing a red LED at IN1 and a blue LED at EA and EB. I guess something is wrong, but I don't understand why this is happening and how to solve this.
Thanks a million ;)