KeyeStudio EASY PLUG RJ11 Single Relay Module – Isolated Switching Output for Arduino Control Projects

The KeyeStudio EASY PLUG RJ11 Single Relay Module is a controller-friendly switching module for turning external loads on and off from a microcontroller. A relay lets a low-power GPIO signal control a separate circuit, making it useful for automation demos, smart-home prototypes, fans, lamps, pumps, and STEM control experiments.

The RJ11 EASY PLUG format is designed for tidy cabling in KeyeStudio-compatible learning systems. It can be used alongside Arduino-compatible controllers such as the ELAB Nano V3, control panels based on the UNO R3 Prototype Expansion Board, and sensing modules such as the HS-S05A Sound Microphone Sensor.

Relays can switch higher voltages than logic circuits, so wiring must be handled carefully. Keep mains wiring isolated, use proper enclosures, and test first with low-voltage loads if you are building an educational project.

Technical Specifications

Board Layout & Label Guide

• RJ11 Port – EASY PLUG connector for controller-side signal wiring.
• Relay – Mechanical switch that controls the external load circuit.
• COM – Common relay contact.
• NO – Normally open contact, closes when relay activates.
• NC – Normally closed contact, opens when relay activates.
• Indicator LED – Shows relay input or active state on many relay modules.
• Mounting Holes – Secure the module before connecting load wiring.
• Safety Gap – Keep load wiring separated from logic wiring.

Application Scenarios

1. Arduino Relay Blink

Switch the relay on and off every second for a low-voltage load test.

const int relayPin = 7;void setup() { pinMode(relayPin, OUTPUT);}void loop() { digitalWrite(relayPin, HIGH); delay(1000); digitalWrite(relayPin, LOW); delay(1000);}

2. Sensor-Controlled Fan

Turn on a relay when a sensor value exceeds a threshold.

const int sensorPin = A0;const int relayPin = 7;void setup() { pinMode(relayPin, OUTPUT);}void loop() { int value = analogRead(sensorPin); digitalWrite(relayPin, value > 600 ? HIGH : LOW); delay(200);}

3. Timed Pump Output

Run a pump relay for a short fixed duration.

const int relayPin = 7;void setup() { pinMode(relayPin, OUTPUT);}void loop() { digitalWrite(relayPin, HIGH); delay(5000); digitalWrite(relayPin, LOW); delay(60000);}

Packing List

• 1 x KeyeStudio EASY PLUG RJ11 Single Relay Module

FAQ

Q: What does this module do?
A: It lets a microcontroller switch an external load through a relay.

Q: What is RJ11 used for?
A: The RJ11 connector is for EASY PLUG controller wiring.

Q: What are NO and NC?
A: NO closes when activated; NC opens when activated.

Q: Can I switch mains voltage?
A: Only if you understand the relay rating and use proper safety practices and enclosures.

Q: Does it isolate the load?
A: Relay contacts provide electrical separation between control and load circuits.

Q: Why does the relay click?
A: That is the mechanical contact switching.

Q: Can I use PWM?
A: No, relays are for slow on/off switching, not PWM speed control.

Q: What should I test first?
A: Use a low-voltage load to confirm logic polarity and wiring.