| H4855 module connector | |||
| Pin | Name | Description | |
| 1 | SW2#3 | Volume control switch, pin 3 | |
| 2 | SW2#4 | Volume control switch, pin 4 | |
| 3 | SW2#5 | Volume control switch, pin 5 | |
| 4 | SW2#6 | Volume control switch, pin 6 | |
| 5 | SW1#1 | Channel switch, pin 1 | |
| 6 | SW1#2 | Channel switch, pin 2 | |
| 7 | SW1#4 | Channel switch, pin 4 | |
| 8 | SW1#8 | Channel switch, pin 8 | |
| 9 | MIC | Side connector pin 1 | |
| 10 | ? | Side connector pin 2 | |
| 11 | SPK | Side connector pin 3 | |
| 12 | +VOUT | Side connector pin 4 | |
| 13 | ? | Side connector pin 9 | |
| 14 | RXD | Side connector pin 10, CMOS UART RX | |
| 15 | TXD | Side connector pin 11, CMOS UART TX | |
| 16 | PTTSEL | Side connector pin 12, 0 = single, 1 = dual | |
| 17 | PTT | Side connector pin 6 | |
| 18 | ? | Side connector pin 7 | |
| 19 | ? | Side connector pin 8 | |
| 20 | ? | Side connector pin 8 | |
| 21 | GND | Side connector pin 5, GND | |
| 22 | GND | Side connector pin 5, GND | |
| 23 | GND | Power GND | |
| 24 | GND | Power GND | |
| 25 | GND | Power GND | |
| 26 | +VIN | Power IN | |
| 27 | +VIN | Power IN | |
| 28 | +VIN | Power IN | |
| 29 | BCD#8 | Side BCD switch, pin 8 | |
| 30 | BCD#1 | Side BCD switch, pin 1 | |
| 31 | BCD#4 | Side BCD switch, pin 4 | |
| 32 | BCD#2 | Side BCD switch, pin 2 | |
| 33 | +VIN | Power IN | |
| 34 | +VIN | Power IN | |
| 35 | +VIN | Power IN | |
| 36 | GND | Power GND | |
| 37 | GND | Power GND | |
| 38 | GND | Power GND | |
| 39 | GND | Side connector pin 5, GND | |
| 40 | GND | Side connector pin 5, GND | |
| 41 | ? | Side connector pin 8 | |
| 42 | ? | Side connector pin 8 | |
| 43 | ? | Side connector pin 7 | |
| 44 | PTT | Side connector pin 6 | |
| 45 | PTTSEL | Side connector pin 12, 0 = single, 1 = dual | |
| 46 | TXD | Side connector pin 11, CMOS UART TX | |
| 47 | RXD | Side connector pin 10, CMOS UART RX | |
| 48 | ? | Side connector pin 9 | |
| 49 | +VOUT | Side connector pin 4 | |
| 50 | SPK | Side connector pin 3 | |
| 51 | ? | Side connector pin 2 | |
| 52 | MIC | Side connector pin 1 | |
| 53 | SW1#8 | Channel switch, pin 8 | |
| 54 | SW1#4 | Channel switch, pin 4 | |
| 55 | SW1#2 | Channel switch, pin 2 | |
| 56 | SW1#1 | Channel switch, pin 1 | |
| 57 | SW2#6 | Volume control switch, pin 6 | |
| 58 | SW2#5 | Volume control switch, pin 5 | |
| 59 | SW2#8-12 | Volume control switch, pins 8 – 12 | |
| 60 | SW2#2 | Volume control switch, pin 2 | |
| H4855 side connector | |||
| Pin | Name | Description | |
| 1 | MIC | Microphone input | |
| 2 | |||
| 3 | SPK | Speaker output | |
| 4 | +VOUT | 3V output | |
| 5 | GND | Signal ground | |
| 6 | PTT | Push to talk, short with GND to transmit | |
| 7 | |||
| 8 | |||
| 9 | |||
| 10 | RXD | CMOS 3V UART RXD (input) | |
| 11 | TXD | CMOS 3V UART TXD (output) | |
| 12 | PTTSEL | Single/Dual PTT selection (0 = single, 1 = dual) | |
