Wait, do you have the black wire of your batteries also connected to the black wire of the servos (as well as to GND)?
@Kim started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Wait, do you have the black wire of your batteries also connected to the black wire of the servos (as well as to GND)?