Now we do our conversions just like above. 121.779 / 5280 = .023 miles .94 / 60 / 60 = .000261 hours .023 / .000261 = 88.12 mph. So there you have it! How to calculate how fast you throw a baseball without a radar gun and only a stop watch.
IR Receiver and Remote. An IR receiver can detect bursts of infrared light sent by a common remote controller (like for a television), and then output a pattern of high/low signals to a Propeller I/O pin. This quick tutorial will first show you how to wire up the infrared receiver.
Radar, which stands for Radio Detection and Ranging, works by transmitting electromagnetic waves that bounce off of a moving object. After the wave is reflected by an object, it changes frequency, and the radar machine interprets the frequency in a calculation of speed.