Do you mean updating the JS code on the devices, or updating the Espruino firmware itself?
If it's the JS code then you can absolutely push firmware updates on connection - but it'd be up to your app to do it.
There is an app for Bangle.js devices where you can supply some code and it will automatically connect to any Espruino device in range and program it: https://banglejs.com/apps/?id=espruinoprog
But I'd recommend that you only use that when preparing for production - normally you'd have added some code to your device that would either disable the bluetooth UART functionality or would password protect it so someone else couldn't write to it.
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.
Do you mean updating the JS code on the devices, or updating the Espruino firmware itself?
If it's the JS code then you can absolutely push firmware updates on connection - but it'd be up to your app to do it.
There is an app for Bangle.js devices where you can supply some code and it will automatically connect to any Espruino device in range and program it: https://banglejs.com/apps/?id=espruinoprog
But I'd recommend that you only use that when preparing for production - normally you'd have added some code to your device that would either disable the bluetooth UART functionality or would password protect it so someone else couldn't write to it.