Is bluetooth open source

I think everyone's covered this already, but just to add my take:

• All the code we have written for Bangle.js is open source. If you wish you can modify and recompile as you see fit
  
• Part of the firmware on the watch (effectively the 'driver' that talks to the hardware) is closed source, but this does not affect your ability to modify Bangle.js however you see fit.
  
  

If you're being totally strict then no, not every byte of the code inside Bangle.js is open because of that driver code, but this is for practical reasons.

Even if the Bluetooth stack was open, you could probably argue that because the ARM microcontroller is closed source, there was some code in there (be it microcode or something in ROM) that was still closed source. It's where you draw the line really.

We're trying to do the best we can to provide an open, flexible experience. That means spending money and developer time on creating usable, open software rather than ensuring every last byte of code is open in the most extreme sense.

If the only thing you care about is your device being fully open then maybe Bangle.js isn't for you, but maybe PineTime isn't either. You probably need to try and find some RISC-V based device.