This is an error using the Web Bluetooth Puck.js library by the look of it (no callback function supplied?) so it's not related to the hardware at all.
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.
Maybe you could post up the code you're using?
This is an error using the Web Bluetooth Puck.js library by the look of it (no callback function supplied?) so it's not related to the hardware at all.