| Pin | Signal | Description | 
|---|---|---|
| 1,6,10,21 | GND | |
| 2,3,4,5 | Charge IN | 5V | 
| 7 | USB Client 5V IN | |
| 8 | USB Client D- | |
| 9 | USB Client D+ | |
| 11 | USB Host Power Out | +5V | 
| 12 | RXD | RS232 level - for GPS receiver (for example) | 
| 13 | TXD | RS232 level - for GPS receiver (for example) | 
| 14 | CTS | |
| 15 | RTS | |
| 16 | DTR | |
| 17 | DSR | |
| 18 | DCD | |
| 19 | Cradle 3V | |
| 20 | Audio Out Right | |
| 22 | Audio Out Left | |
| 23 | Cradle CHG_ENB | |
| 24 | Audio Out switch (active low) | should be connected to GND by button to switch Ext/Int audio | 
| 25 | USB Host D- | |
| 26 | USB Host D+ | 

