LED Traffic Light Signal Module

Specifications

• Operating Voltage: 3.3V to 5V DC (Optimized for 5V)
• LED Colors: Red, Yellow, Green (Diffused 5mm or 8mm LEDs)
• Interface Type: Digital Logic (Common Cathode)
• Integrated Components: On-board current limiting resistors for safe direct-pin connection
• Dimensions: Approx. 56mm x 21mm x 11mm
• Mounting: Standard through-holes for easy screwing/standoffs
• Pin Pitch: Standard 2.54mm (0.1") header pins

Applications

• STEM Education: The perfect introductory project for teaching 'if/else' statements and delay loops in coding classes.
• Smart City Prototypes: Add realistic traffic management to your automated robot car tracks.
• Model Railways: Excellent signal indicators for scale train layouts.
  Industrial Status Indicators: Use as a mini Andon light to display machine states (Running, Warning, Stopped) on custom control panels.

Unlock New Capabilities

• Past Projects: If you've mastered blinking a single built-in LED on your Arduino, you are ready for this.
• Feature Upgrade: This module unlocks your ability to code State Machines—a fundamental concept in computer science where a system transitions between different active states (e.g., Red -> Green -> Yellow -> Red) based on precise timing or sensor inputs.
• Effort/Requirements: Beginner Level. You only need an Arduino, 4 jumper wires, and about 10 minutes of coding.
• Virtual Technician & Wiring Guide ⚠️ Safety Warning: This is a 5V logic device. Do not supply 12V or 24V directly to the pins without a step-down converter, or the LEDs will burn out instantly.

Standard Arduino Wiring (Common Cathode):

• GND Pin: Connect to Arduino GND
• R (Red) Pin: Connect to Arduino Digital Pin 10
• Y (Yellow) Pin: Connect to Arduino Digital Pin 9
• G (Green) Pin: Connect to Arduino Digital Pin 8

Package Includes:

• 1 X LED Traffic Light Signal Module 

Frequently Asked Questions (Technical FAQs)

• Does this module require external resistors?
  No, it has built-in surface-mount resistors, allowing you to connect it directly to your microcontroller's GPIO pins safely.
• Can I use this with a 3.3V board like the ESP32 or Raspberry Pi Pico?
  Yes, it works at 3.3V, though the LEDs will be slightly dimmer than when powered by a 5V logic source.
• Is this a Common Anode or Common Cathode configuration?
  This module uses a Common Cathode design. You provide a shared Ground (GND) and apply a HIGH signal to the color pins to turn them on.
• What is the maximum current draw per LED?
  Each LED draws approximately 15-20mA at 5V, which is perfectly safe for standard Arduino GPIO pins.
• Can I use PWM to dim the LEDs?
  Yes, if you connect the R, Y, or G pins to PWM-capable pins on your microcontroller, you can use analogWrite() to adjust their brightness.
• Can I turn on multiple LEDs at the same time?
  Absolutely. You can drive any combination of the Red, Yellow, and Green pins HIGH simultaneously.
• Is this module breadboard compatible?
  Yes, the 2.54mm pitch headers plug directly into a standard breadboard or female jumper wires.
• Will this work with MicroPython?
  Yes, it is purely hardware. You can control it using standard machine.Pin toggles in MicroPython.
• Is the module waterproof for outdoor use?
  No, the PCB and components are exposed. For outdoor use, it must be housed in an IP-rated enclosure.
• What is the viewing angle of the LEDs?
  They are standard diffused LEDs, providing a wide viewing angle of roughly 60-120 degrees, making them highly visible from the sides.
• Why is my Yellow LED slightly dimmer than the Red or Green?
  Yellow LEDs naturally have a different forward voltage drop and luminous intensity. Even with matched resistors, slight visual variations in brightness are normal due to the human eye's sensitivity.
• How do I code a realistic traffic sequence?
  A standard sequence uses delays: Green (High) -> Delay -> Green (Low), Yellow (High) -> Delay -> Yellow (Low), Red (High) -> Delay -> Repeat.
• Can it run directly off a 9V battery?
  No. Providing 9V directly to the signal pins will bypass the voltage tolerance of the onboard resistors and destroy the LEDs.