The store will not work correctly in the case when cookies are disabled.
Best Modules will be closed from Apr. 3nd to Apr. 6th in observance of Tomb Sweeping Day. Please be informed that any orders placed after 15:00 PM Apr. 1st (Taiwan time, UTC+8) will be processed on Apr. 7th.
We use cookies for optimal website use.We recommend you to allow cookies for a better user experience. Please read our privacy policy. Learn more.
The BM22S2021-1 is a smoke detector sensor with two channels (LED transmitters) to detect white smoke and black smoke. Each sensor has been calibrated at the factory. When the concentration of smoke exceeds the default calibration, the voltage output of the alarm pin (pin 5) 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.