I'm using a RedBoard to try to activate a back-and-forth motion of 2 servo motors (SG90s) with a fingerprint scanner (GT-521F32). Everything runs fine the first 2 times I place my finger on the scanner, but after the second time the motor starts jittering. When I place my finger on the scanner a third time, the jittering stops, but the motor does not turn. As soon as I remove my finger, the jittering continues.
I checked the voltage being delivered to each component with a multimeter and everything seems fine on that front. I've tried connecting the RedBoard to the wall as well as USB. I've also tested each component individually with sample codes I've found online, and all components work perfectly fine by themselves.
Here's a pastebin of the code: FPS w/ 2 servos - Pastebin.com
Thanks in advance!