This is a very simple arduino project where a led is turned on by setting the pin 13 as output, then write it with a high value, in our case that means that pin 13 will deliver 5 volts. Advertisement ...

Here is a simple, yet useful circuit of an Arduino 4-digit 7-segment LED display unit. The module used here is a self-contained, compact common-cathode module containing four 7-segment LED numeric ...

It is a pretty common first project to use an Arduino (or similar) to blink an LED. Which, of course, brings taunts of: you could have used a 555! You can, of course, also use any sort of oscillato… ...