Replacing the speaker with an LED results in pulses of light rather than sound. These light pulses are just like Morse code pulses and can be received using the same receiver circuit as the Morse code ...

I found that we could get the radio to reach the length of a 60ft bowling alley, but it worked best with one long range version as the receiver, and a standard module for transmitting.

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… ...

Arduino open source long-range RC transmitter. 12:14 pm January 31, ... but it worked best with one long range version as the receiver, and a standard module for transmitting.