The red LED in the circuit indicates the presence of the input supply ... Luca Dentella has written a great tutorial on how to interface ACS712 current sensor with an Arduino. For more details and ...

The hardware is consists of an Arduino microcontroller (here an Arduino Uno R3) and a pre-wired soil moisture sensor module ... be linked to the little circuit shown below, and use an external 5VDC ...

An Arduino is a microcontroller ... You'll need the sensor module R305 to read your fingerprint and a list of other ...