For about the same cost as of case of PBR, you can buy a cheap software defined radio called the RTL-SDR. With this simple USB dongle, you can turn your PC into a wideband radio scanner and use it to sniff out RF signals anywhere from 25 MHz to 1700 MHz. In case you’re not familiar, an SDR receiver works a lot like a traditional radio transceiver, except that most, if not all, of the signal processing that would normally happen in hardware, is done with software instead. Essentially, an SDR receiver captures the raw radio signals (using a tuner), Continue Reading
sensors
A wireless water level sensor for the Internet of Tannenbaums
I rigged up a crude little water level sensor to monitor my Christmas tree and send me alerts when it gets thirsty. With the help of two strips of aluminum stuffed in a FoodSaver bag, an Adafruit HUZZAH32 – ESP32 Feather Board, and a little Arduino code, our humble tree has become part of the IoT revolution! Physics lab flashback The sensing probe that goes in the water is basically just a parallel plate capacitor straight out of undergrad physics. The water flows between the plates and works as a dielectric. The relative permittivity (aka dielectric constant) of water is Continue Reading