The interface board uses an independent MCU (STM32G0B0RET6) to manage external IO, power, and peripheral control. It communicates with the core processing board via UART0.
Interface Overviewβ
External Interfaces β Exposed on the device enclosure for user access:
| # | Function | Description | Category |
|---|
| 1 | Alarm I/O | Alarm input/output | Product |
| 2 | RS-485 | Serial communication bus | Product |
On-Board Resources β Implemented features:
| # | Function | Chip/Module | Description | Category |
|---|
| 3 | IR-CUT Driver | IR-CUT device | Day/night filter switching | Internal |
| 4 | Light Sensor Detection | Photoresistor | ADC ambient light sampling | Internal |
| 5 | IR Light Board Driver | External light board | Near/Far-IR LED PWM | Internal |
| 6 | LENS Driver | AN41908A-VBA | SPI lens driver | Internal |
| 7 | System LED | β | Blue status LED | Internal |
| 8 | Temperature Sensor | LMT87DCK | ADC temperature sampling | Internal |
| 9 | Bidirectional Reset | SN74LVC1G14DCK + PD8 | SoC resets MCU (chip) / MCU resets Processor Board (PD8) | Internal |
| 10 | RTC | Supercapacitor | VBAT power-fail retention | Internal |
Internal Reserved Resources β Reserved features, not yet enabled:
| # | Function | Chip/Module | Description | Category |
|---|
| 11 | Radar Power Enable | β | PB0 power control | Internal (Reserved) |
| 12 | Dual-Light Board Driver | External light board | White/Red LED PWM | Internal (Reserved) |
| 13 | Fan Driver | β | 12V fan enable | Internal (Reserved) |
| 14 | Heater | β | 12V heater enable | Internal (Reserved) |
Debug Interfaces β For development and debugging:
| # | Function | Description | Category |
|---|
| 15 | ST-LINK | SWD debug port | Debug |
| 16 | Debug UART1 | USART1 | Debug |
External Interfacesβ
Alarm I/Oβ
Alarm input/output on the device enclosure.
| Pin | Function | Note |
|---|
| PB13 | Alarm_IN0 | External alarm input 0 |
| PB14 | Alarm_IN1 | External alarm input 1 |
| PA8 | Alarm_OUT0 | Alarm output 0 (level output) |
| PA9 | Alarm_OUT1 | Alarm output 1 (multiplexed with USART1_TX) |
Note: The MCU exposes 2 Alarm IN pins (PB13/PB14), but the product enclosure connector only routes out 1 Alarm IN.
RS-485 serial communication on the device enclosure.
| Pin | Function |
|---|
| PC4 | RS485_TXD3 (Transmit) |
| PC5 | RS485_RXD3 (Receive) |
| PB1 | RS485_EN (Transceive enable) |
On-Board Resourcesβ
IR-CUT day/night filter driver.
| Pin | Function | Note |
|---|
| PB8 | IR_CUT_EN (IR-CUT driver enable) | Supports auto / day / night three-mode switching |
Light Sensor Detectionβ
Photoresistor ADC sampling for ambient light threshold detection, driving automatic day/night mode switching.
| Pin | Function | Note |
|---|
| PA1 | PD_ADC (ADC1_IN1, photoresistor sampling) | Ambient light threshold detection |
Light Board Driversβ
The interface board controls external light boards via PWM (independent physical modules connected via connectors).
IR Light Board (Near-IR/Far-IR):
| Pin | Function |
|---|
| PC9 | PWM_Far (Far-IR PWM) |
| PC8 | PWM_Near (Near-IR PWM) |
LENS Driver (AN41908A-VBA)β
The MCU SPI1 interface controls the AF auto-zoom and autofocus lens module. The SoC-side SPI CS1 is also connected to the same chip (default control path), while the MCU side handles lens homing and limit protection.
| Pin | Function |
|---|
| PA5 | SPI1_CLK (SPI clock) |
| PA6 | SPI1_MISO (SPI master in slave out) |
| PA7 | SPI1_MOSI (SPI master out slave in) |
| PA4 | SPI1_CS (SPI chip select) |
| PB3 | LENSPOWER_EN (Lens power enable) |
| PD6 | F_RST (Focus reset) |
| PD5 | Z_RST (Zoom reset) |
| PD4 | RSTB (Master reset) |
| PD3 | PLS2 (Step control 2) |
| PD2 | PLS1 (Step control 1) |
| PD1 | VD_FZ (Vertical drive Focus/Zoom) |
| PD0 | LS_FZ (Limit switch Focus/Zoom) |
System LEDβ
| Pin | Function | Note |
|---|
| PD9 | SYS-LED (System status LED) | Blue, MCU direct control |
Temperature Sensor (LMT87DCK)β
| Pin | Function |
|---|
| PB2 | Temp_ADC (Temperature ADC sampling) |
Main Board Resetβ
MCU controls core processing board reset via PD8. Conversely, the SoC can also reset the MCU via H_GPIO_18 (SN74LVC1G14DCK) (see Core Board).
| Pin | Function |
|---|
| PD8 | POWER_RST (Core processing board reset control) |
MCU VBAT powered by external supercapacitor to maintain RTC operation, synchronized with core processing board system time.
| Function | Description |
|---|
| RTC Power | VBAT with external supercapacitor |
| Time Sync | MCU RTC synchronized with core processing board |
| Power-Fail Retention | Supercapacitor maintains RTC operation |
Internal Reserved Resourcesβ
Radar Power Enableβ
MCU controls the radar module power switch.
| Pin | Function |
|---|
| PB0 | Radar_EN (Radar power enable) |
Dual-Light Board Driverβ
| Pin | Function |
|---|
| PB4 | PWM_R (Red light PWM) |
| PB5 | PWM_W (White light PWM) |
| PB6 | R_CTL (Red light switch control) |
| PB7 | W_CTL (White light switch control) |
Fan Driverβ
| Pin | Function | Note |
|---|
| PB9 | FAN_EN (Fan enable) | 12V |
| Pin | Function | Note |
|---|
| PA15 | HEAT_EN (Heater enable) | 12V |
Debug Interfacesβ
ST-LINKβ
MCU SWD debug port for firmware flashing and online debugging.
| Pin | Function |
|---|
| PA14 | SWDCLK / BOOT0 |
| PA13 | SWDIO |
UART1 (Debug Serial Port)β
| Pin | Function |
|---|
| PA10 | USART1_RX (Receive) |
| PA9 | USART1_TX (Transmit) |