The BMA36M302 is a semiconductor gas detector module composed of a breakout board and the gas detector sensor BM22S3021-1. The product reads the gas concentration and alarms via UART interface.
The BMA36M302 is mainly used to detect methane. When the gas concentration exceeds the default calibration concentration, the voltage output of the alarm pin STA (pin 1) changes from low level to high level (default).
It is easy to make a gas detector by supplying power to this sensor and monitoring the alarm output pin (STA).
BMA36M302 has been calibrated at the factory to maintain consistent characteristics. The calibrated alarm threshold is 9% LEL (Lower Explosion Limit), approximately equivalent to 4500ppm.
BMA36M302 has the same functions as the BM22S3021-1. The difference between them is that the BMA36M302 uses level shift circuit to break out the BM22S3021-1’s pins to match BMCOM connectors and can directly connect to BMduino development boards, such as BM53A367A.
You can use the product with other development boards, such as Arduino UNO, as well.
| Pin | Pin name | Function |
|---|---|---|
| 1 | STA | Alarm pin
Triggered: output high (default) Non-triggered: output low |
| 2 | RX | UART: RX |
| 3 | TX | UART: TX |
| 4 | VDD | Power supply: 4.9V~5.1V |
| 5 | GND | Ground |
| BMA36M303 | BMA36M302 | |
|---|---|---|
| Type | Catalytic Combustible | Semiconductor |
| Input voltage | 3.0V~3.6V | 4.9V~5.1V |
| Operating current | 150mA @3.3V | 160mA @5V |
| Interface | UART | UART |
| Gas concentration range | 500ppm~10000ppm | 300ppm~10000ppm |
| Alarm threshold | 4500ppm (9%LEL) | 4500ppm (9%LEL) |
| Full range linear deviation | < 3% LEL | - |
| Preheat time | 180 seconds | 180 seconds |
| Factory calibrated | V | V |
| Fault detection function | V | V |
| HS Code (reference) | 8504.50.90.00-5 |
|---|
