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 oscillator, ...

There was a time though when a flashing LED was something of a big deal, so much so that National Semiconductor produced a dedicated chip for the task. The LM3909 boasted the ability to flash an LED ...

This is a very simple but useful project, strobe navigation lights for rc airplanes, or you can adjust the flashing time and make it a warning light for a forklift or even a turn signal light for a ...