You don't have any firmware uploaded (= bank0 invalid) just retry sending firmware zip, you may also try nrfConnect or nrfToolbox from android phone if iphone does not work.
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.
You don't have any firmware uploaded (= bank0 invalid) just retry sending firmware zip, you may also try nrfConnect or nrfToolbox from android phone if iphone does not work.