Powering two L298N motor boards with external supply I have been struggling with this as I'm a complete electronics and arduino beginner. I am trying to power two DVD-drive stepper motors using two L298N motor boards.
For some reason, I can't figure out how to power them using external source.
I can connect one like this straight from the arduino and the motor spins properly:

I know this is bad because it could damage the arduino etc, so I tried to provide a separate power supply to the motor, which in this case is an iphone wall charger which provides 5V, 1A. I also tried with a power bank that supplies 5V, 1A. I wired it up like this but then the motors don't run:

I don't know what I am doing wrong. Any help would be greatly appreciated.
If your second schematic correctly represents your actual wiring, the problem is that you are connecting the arduino 5V pin (instead of the GND pin) to the L298 GND.

I assume you have also connected the control pins of the motor controllers to Arduino pins?