If a jack is plugged in and the THING is turned on, things become interesting:

• As soon as the THING is turned on, voltage on pin 5 drops from +2.5V to 0V for about 0.5 seconds => this provides any external device plugged onto the remote port with a cold reset, as was previously identified
• After this reset phase, +2.5V is turned back on but it is only maintained if the remote device replies to a specific query within 5 secs.
• If no proper reply came from the external device within 5 secs, external voltage is turned off, until the THING itself is powered off in

Pin	Wire color	Function
1	Brown	? Shield ? (GND) - (unused by standard Remote/Headphones)
2	Blue	Digital ground (GND)
3	Orange	TXD
4	Green	Sense? (+2.5V, seems to be controlled by THING) - (unused by standard Remote/Headphones)
5	Yellow	+2.5V (0V when Plug isnt inserted) *1
6	Grey	RXD
Tip	Pink	Left audio (plus 600mv DC BIAS)
Ring	Red	Right audio
Sleeve	Black	Audio ground (GND)