To listen in on the sensors, [Jeff] employed a Nooelec NESDR—a software defined radio that could pick up the 319.5 MHz signals. The NESDR runs a tool called RTL_433, which can decode the sensor ...

Tuning in with an RTL-SDR (Nooelec NESDR Nano 2) had the Beepy gulping down between 770 and 800 mAh, which would be enough to drain the battery in under two and a half hours. I’d estimate that ...