Here is the basic circuit diagram of the UV Sensor Module, drawn & checked by me (thanks to my USB microscope and LCR meter).In the circuit PD1 is the GUVA-S12SD, and U1 is the SGM8521. The only one ...

Here is a motor speed sensor module, the major goal is to check the rate of an electric motor. The module can be used in association with a microcontroller for motor speed detection, pulse count, ...