Features

1. Operating voltage: 3.0V – 5.5V
2. Operating current: 1.5mA typical (3.3V/object detected at 85cm/scanning time = 0.5s)
3. Standby current: 14µA typical (3.3V/default at 85cm/scanning time = 0.5s)
4. Detection distance: 1 - 100cm (at 25°C, indoor, reflector is A4 paper), default 85cm
5. I/O mode: Output pin is normal high, active low (when an object is detected), configurable
6. UART mode:
   9600bps
   Send any command to module within 0.5s after power-on to enter the UART mode
   Minimum continuous reading time = 10ms
7. Factory-calibrated

Arduino Demo Code

The demo code reads the proximity sensing trigger threshold value and displays on the serial monitor. Since the BM32S2021-1 can only enter UART mode at the condition of receiving a command after powered up, please upload the code to the board first and then connect the 4 wires of the module to the Arduino board at the same time.

Wire connection:

1. Module pin 1 (VDD) connects to Arduino UNO pin 5V
2. Module pin 2 (GND) connects to Arduino UNO pin GND
3. Module pin 3 (TX) connects to Arduino UNO pin 2
4. Module pin 4 (RX) connects to Arduino UNO pin 3

The result shown on the serial monitor is

Product Information

1. Body size: 17.5 x 10.1 x 7.1 (mm)
2. Weight: 0.8 g
3. Packing List: BM32S2021-1 Proximity Sensing Module x 1

Resources

Module: Holtek BM32S2021-1, Proximity Sensing Module