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How to make an LED flash with a 555 Timer.

555 Timers are a great intro to electronics, so I thought I'd throw together a quick guide on how to set up a simple flashing LED, as a sort of "hello world" project.

What you'll need

  1. 555 Timer x1
  2. 470K Resistor x1
  3. 1K Resistor x2
  4. Single Colour LED x1
  5. 1uF Capacitor x1
  6. 9V DC source x1

Circuit Diagram and 555 Timer pinout

555 Timer pinout:

Circuit Diagram:

Construct the above circuit, plug it in, and watch your LED flashing! To adjust the frequency, you can vary the potential divider, in this configuration, it's about 2Hz. It works by using the IC as an astable multivibrator, and just sticking an LED on the output to show it. There's a pretty good explanation of how it works here.