PDA connectors and cables 4 conductor diagram
4 pin 3.5mm (2.5mm) plug connector at the headset cable
|1||Left||audio channel (tip)|
|2||Right||audio channel (1st ring)|
|3||Microphone||input channel (2nd ring)|
- If 3-pin 2.5 mm standard headphone headset detected, the pinout is following: pin 1 (tip) - mic, pin 2 - earbud, pin 3 - ground.