^  J_RS1                     ^^  J1_RS485                   ^^  J_GPIO2                 ^^  SPK1                     ^^  UART1                   ^|
| 1           | UART_RX1_232  | 1           | RS485_A1       | 1         | GPIO1         | 1        | L_SPK+          | 1         | UART1_RX_CON  |
| 2           | UART_TX1_232  | 2           | RS485_B1       | 2         | GPIO3         | 2        | L_SPK-          | 2         | UART1_TX_CON  |
| 3           | UART_RX2_232  | 3           | VCC5_485_1     | 3         | GPIO2         | 3        | R_SPK+          | 3         | VCC3_TTL      |
| 4           | UART_TX2_232  | 4           | GND            | 4         | GPIO4         | 4        | R_SPK-          | 4         | GND           |
| 5           | UART_RX3_232    ^  J2_RS485                 ^| 5         | GPIO7         ^  J_KEY1                   |^  PUSB1                   ||
| 6           | UART_TX3_232  | 1           | RS485_A2       | 6         | GPIO5         | 1        | GND             | 1         | USB_VCC5      |
| 7           | UART_RX4_232  | 2           | RS485_B2       | 7         | GPIO8         | 2        | POWER_ON_BT     | 2         | USB_D1N       |
| 8           | UART_TX4_232  | 3           | VCC5_485_2     | 8         | GPIO6         | 3        | KEY_Reset       | 3         | USB_D1P       |
| 9           | GND             ^  I2C-TP                   ^| 9         | VCC5_GPIO     | 4        | RECOVER_BUTTON  | 4         | GND           |
| 10          | GND           | 1           | GND            | 10        | VCC5_GPIO     |          |                 |           |               |
^  debug                     ^| 2           | I2C4_SDA_M2    | 11        | GND           ^  HOST1                    |^  PUSB2                   ||
| 1           | NC            | 3           | I2C4_SCL_M2    | 12        | GND           | 1        | HOST1_VCC5      | 1         | USB_VCC5      |
| 2           | UART2_TX      | 4           | TP_RST_C       |           |               | 2        | HOST1_D1N_CON   | 2         | USB_D2N       |
| 3           | UART2_RX      | 5           | TP_INT_C       |           |               | 3        | HOST1_D1P_CON   | 3         | USB_D2P       |
| 4           | GND           | 6           | TP_VCC         |           |               | 4        | GND             | 4         | GND           |