KS2E Relay Reference
A dual-channel SPDT (single-pole, double-throw) relay module. Each relay switches a separate high-power circuit based on its coil being energised from a low-power GPIO signal.
Pin names
| Name | Description |
|---|---|
| NO1 / NO2 | Normally Open contact — connected to COM when the coil is energised |
| NC1 / NC2 | Normally Closed contact — connected to COM when the coil is de-energised |
| P1 / P2 | Common (COM) contact for each relay |
| COIL1 | Relay 1 coil control input |
| COIL2 | Relay 2 coil control input (GND return) |
Attributes
This component has no configurable attributes.
Usage
Drive each coil pin from a GPIO through a transistor/driver (relay coils draw more current than a GPIO can source directly — most relay modules include this driver circuitry onboard). Wire the high-power load between P (COM) and either NO or NC depending on the desired default state.
const int RELAY1_PIN = 7;
void setup() {
pinMode(RELAY1_PIN, OUTPUT);
}
void loop() {
digitalWrite(RELAY1_PIN, HIGH); // energise: COM connects to NO1
delay(1000);
digitalWrite(RELAY1_PIN, LOW); // de-energise: COM connects to NC1
delay(1000);
}Relays switch mains-voltage or high-current loads that must stay electrically isolated from the Arduino's low-voltage logic — always double-check polarity and current ratings on real hardware before switching a live circuit.
Examples
| Description | Attrs |
|---|---|
| Default dual relay module | {} |
See also
- Servo Motor — another common GPIO-controlled actuator