Municipal potable water tank monitoring: the system consists of a Raspberry B+ with UPIS power backup, a Teltonika twct22 controller, a USB<-->RS232 converter and a 3G USB stick (huawei modem firm), recorded parameter is 3G signal, refresh rate ~20sec

Propane tank level as measured by a ratiometric hall effect sensor mounted over the tank's analog dial gage. Uses an Arduino Mini Pro and an ESP8266 Wi-Fi module, powered by a 3.2V LiFePo4 battery and solar cell.