It works in two different modes, Normally Open (NO) and Normally Closed (NC). in our project, we will use it in Normally Open mode which means when the relay is switched off the circuit will be broken ...

Step 1 (Connect SIM900 With Arduino) Use picture as a reference for connecting SIM900 to Arduino. Step 2 (Connect Relay with Arduino) Connections are given Below : Arduino Relay Module +5V VCC GND GND ...

Relay Driver Circuit Explanation: In this 4-Channel Relay Driver Circuit we have used an optocoupler whic his triggered by active LOW signal, to trigger the NPN transistor which further drives the ...

The board pinout is compatible with Arduino MKR board and can be programmed with Arduino IDE thanks to the STM32Duino project. Alternatively, you could also use the SWD header to program the board via ...