433 MHz radio signals are all around us ... To help in those efforts, [Joonas Pihlajamaa] has written a three-part tutorial on decoding these signals. A soundcard makes for a very cheap oscilloscope.

Presented below is a simple and cheap 433-Mz RF Sniffer ideal for testing/reverse-engineering most 433-MHz wireless devices. As you can see, the setup is on the Arduino ground with a 433-MHz receiver ...