Grove Red LED 5mm Module

Quick Answer: The Grove Red LED 5mm Module is a single 5 mm red light-emitting diode on a Grove board, ready to plug into a digital port without breadboard wiring. The Grove red LED is usually the first output students program: they blink it, fade it and use it as a warning indicator.

The First Output Most Students Program

Blinking an LED is the ‘hello world’ of physical computing. With the Grove Red LED 5mm Module, students set a pin HIGH to light the LED, wait, set it LOW and wait again, then change the delays and watch the effect. That short loop teaches output pins, timing and the idea that a program runs continuously on the controller.

Red has a special role as an indicator colour because people read it as stop, danger or fault. Students therefore use the red module for warnings: soil that is too dry, a temperature that is too high, an intruder detected. Red LEDs also need a slightly lower forward voltage than green or blue ones, a detail that comes up when students compare modules and discuss why a series resistor is needed.

On many Grove LED boards the LED sits in a socket so it can be swapped; if so, the longer leg goes to the positive mark. Whether this board includes a brightness adjuster should be confirmed before ordering.

Applications

• Blink and pattern programs as a first coding exercise
• Warning indicators for sensor thresholds, such as dry soil or high temperature
• Traffic-light sequences combined with the Green LED module 5 mm Grove
• Fading with PWM to show how duty cycle controls apparent brightness
• Morse code output and reaction games triggered from the Grove Push Button Module

Specifications

Care & Handling

• If the red LED sits in a socket, check its polarity when refitting: the longer leg is positive.
• Remind students not to shine LEDs into each other’s eyes or stare into one at close range.
• Plug and unplug the Grove cable by its housing, not the wires.
• Keep spare LEDs of the right colour and size with the class set in case one is damaged.

Why Choose LabEquip

LED modules are bought in larger numbers than most other Grove parts because every student starts with one. LabEquip lists the red module in its Stem Kits category with matching green and RGB versions; use the contact page for class-set quantities.

Frequently Asked Questions

Why does the LED module need no extra resistor?

The Grove board already includes the current-limiting parts the LED needs, so it can be plugged straight into a Grove port. With a bare LED on a breadboard, students must add a series resistor to avoid burning it out.

How can I make the LED fade instead of blink?

Connect it to a PWM-capable pin and write values between 0 and 255 in Arduino code. The LED switches on and off very fast, and the fraction of time it is on, the duty cycle, sets how bright it looks.

What is the difference between the red and green LED modules?

Mainly colour and its meaning: red usually signals stop, fault or warning, while green signals go or OK. Red LEDs also have a slightly lower forward voltage. Both are programmed in exactly the same way.

The LED does not light. What should I check?

Check that the cable is in the digital port the code uses, that the pin is set as an output, and, if the LED is socketed, that it is fitted the right way round. Try another port to rule out a faulty cable.

Can one pin drive several LED modules?

Each Grove LED module normally uses its own port. To control several LEDs, plug them into separate digital ports, or use a multi-LED module such as an LED bar designed for a single port.

Is it bright enough for a classroom demonstration?

It is clearly visible on a desk and to a small group. For whole-class demonstrations, a larger 8 mm LED or a display module is easier to see from the back of the room.

Last Updated: September 2026