Old infrared remote controls can be a great way to interface with your projects. One of [AnalysIR’s] latest blog posts goes over the simplest way to create an Arduino based IR receiver, makin… ...

The transmitter and receiver. For the transmitter, he turned an Arduino Pro Micro into a USB sound card which he could plug into his laptop.

We use LEDs to generate (very high frequency) radio waves and photo-resistors to take the place of radio antennas. These ideas are identical to concepts used in cell phones and Wi-Fi. Initially we ...