Using pins D9 & D10 on the MDBT42Q

Nice - ok, I've just added some code in for that. I didn't merge your code exactly as it was because actually there are some potentially bad side-effects of trying to execute JS in a IRQ (which can happen if you do NRF.restart() and then disconnect from BLE).

So @consolenaut you can now flash a cutting-edge build, then just run the following:

NRF.disconnect();setTimeout(function() { NRF.restart(function(){ LED.set();
poke32(0x4001e504,1);while(!peek32(0x400­1e400)); // enable flash writing
poke32(0x1000120c,0xfffffffe);while(!pee­k32(0x4001e400)); // NFC pins as GPIO
poke32(0x4001e504, 0);while(!peek32(0x4001e400)); // disable flash writing
});}, 1000);

Afterwards you should see peek32(0x1000120c).toString(16) == "fffffffe" and once you reboot the device you'll have the NFC pins available.