(GND) pin of Relay Connect to-ve pin (GND) of NodeMCU.

To switch on the output load we need to trigger the relay to High Status.

NO (Normally Open): The normally open contact terminal is used when you want to switch on the load based on your need.

As soon relay is ON the load will turn OFF by switching relay to NO contact. Means load is in always high or ON condition until we switch on the relays.

NC (Normally Closed): The normally close contact terminal is used when you want the relay to be closed by default.

COM (Common): This terminal features the user to connect what voltage you want to draw to run the load.

common (COM), Normally Closed (NC), and Normally Open (NO).

Any relay basically having three terminal contact to connect output load i.e.

If the relay is no configuration, the load will connect when the coil is activate when the switching action is from NO-NC.

The relay consists of a coil that is activate by 5 V, when the coil has energetic switching action, which is based on the no-NC configuration.

The relay has two configurations not (usually open) and NC (usually closed).

The relay basically performs a switch function between the electrical load and the nodeMCU.

How does the relay module work with node MCU?

After the test was found to trigger or enhance the stability of end to interference, regardless of this module is the electromagnetic interference environment, or instantly through power module, the relay will not malfunction. Many manufacturers have added optocoupler isolation, but with the trigger signal to the module and not isolation, would not achieve the interference effect. signal terminal block is design with a pull and a filter circuit, anti-jamming capability, suitable for industrial control. The module can be controlled: 10A 250VAC (AC), 10A 30VDC (direct current) following loads. If you need more time, more replaceable capacitor (C2) or potentiometer. The time can be adjusted via a potentiometer, default 0-24 seconds.

Originating outside the contact (TRIG) to a low pulse signal, or touch trigger button and instantly, the relay and, working lights, this time, the status of the relay output: normally open (NO) and the common terminal (COM) is turned on, Normally Closed (NC) and the common terminal (COM) is disconnec after 0-24 seconds (this time can be adjusted according to your needs) relay opens after the bell, then relay back to the state before the trigger.Operating mode: feed the module power, output of the module state: normally open (NO) and the common terminal (COM) disconnect, normally close (NC) and the common terminal (COM) is turn on. Working voltage: Wide voltage any voltage between 5-30V, Micro USB power connector and two solder terminals.

Relay module library for proteus 8