BM22S3021-1 is a gas detector digital sensor, mainly used to detect methane (CH4). When the gas concentration exceeds the preset calibration concentration, the voltage output of the alarm pin (pin 5) changes from low level to high level. It is easy to make a gas detector by supplying power to this sensor and monitoring the alarm output pin.
Each BM22S3021-1 is calibrated before leaving the factory to maintain consistent characteristics. The calibrated alarm threshold is 9% LEL (Lower Explosion Limit), which is about 4500ppm.
BM22S3021-1 can automatically transmit its internal status through the UART interface about once every second. The external host controller can receive the status of BM22S3021-1 in real-time without sending a command. In addition, BM22S3021-1 provides up to 26 commands. You can modify the alarm point and do various tests with the commands. The "restore factory settings" command is used to let the BM22S3021-1 return to the factory settings.