| Pin | Name | Description | Direction |
|---|---|---|---|
| 1 | GND | Ground | |
| 2 | TxD | RS232-Txd | OUT |
| 3 | RxD | RS232-RxD | IN |
| 4 | RTS | RS232-RTS | OUT |
| 5 | Max 4.2 | Max 4.2- Boot | |
| 6 | GND | Ground | |
| 7 | GND | Ground | |
| 8 | SPK2N | Lautsprecherausgang negatives Signal | OUT |
| 9 | SPK2P | Lautsprecherausgang negatives Signal | OUT |
| 10 | SCL | inter Kommunikatoinsbus Taktsignal | IN/OUT |
| 11 | SDA | inter Kommunikatoinsbus Datensignal | IN/OUT |
| 12 | CTS | RS232-CTS | IN |
| 13 | Vcc 3V | 3V Ausgang | OUT |
| 14 | DC Volt | Einspeisung vom Ladegerat (9V) | IN |
| 15 | DC Volt | Einspeisung vom Ladegerat (9V) | IN |
| 16 | MIC2P | Mikrofoneingang positives Signal | IN |
| 17 | MIC2N | Mikrofoneingang negatives Signal | IN |
| 18 | +VBatt | Akkuspannung 3.6V | IN |

