Building a Raspberry Pi LED Flasher

In this simple electronics project, you get to build a simple breadboard circuit that connects an LED to a Raspberry Pi via the GPIO port on pin 3 of the header. The figure shows the completed project.

In this project, you connect an external LED to a Raspberry Pi, and then use a simple sketch to turn the LED on and off at 0.5-second intervals.

Parts needed to build an LED flasher

• One Raspberry Pi 2 or 3 with Raspbian installed, connected to a monitor, keyboard, and power
• One small solderless breadboard (RadioShack 2760003)
• One 5mm red LED (RadioShack 2760209)
• One resistor (orange-orange-brown)
• Two jumper wires (M/F)

Steps for building an LED flasher

1. Insert resistor R1.

   R1 – 330 Ω: A3 to ground bus

2. Insert LED1.
   Cathode (short lead): D5 Anode (long lead): D3
3. Connect the ground bus to the Raspberry Pi header pin 2. Use a jumper to connect any hole in the ground bus on the breadboard.
4. Connect pin 3 on the Raspberry Pi A5 on the breadboard.
5. Open the Python 2 IDLE Editor with root privileges.
6. Create and save the sketch shown here, using the filename LedBlink. import RPi.GPIO as GPIO import timeGPIO.setmode(GPIO.BOARD) GPIO.setup(3, GPIO.OUT) while True: GPIO.output(3, GPIO.HIGH) time.sleep(0.5) GPIO.output(3, GPIO.LOW) time.sleep(0.5)
7. Run the LedBlink program by choosing Run →  Run Module (or press F5). The LED on the breadboard will flash on and off at half-second intervals.