Is that possible with Javascript?
Yes, check setRotation and https://banglejs.com/apps/#tool and search for Custom Boot Code app as a first approach.
@MaBe 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.
Yes, check setRotation and https://banglejs.com/apps/#tool and search for Custom Boot Code app as a first approach.