Gasbottle monitor
We have made a prototype weight for the gasbottles via a modified bathroom scale and an ESP32 with a small display. We can read the persentage left in the bottle on the display. The small ESP32 communicates via WiFi to the Raspberry Pi and we can monitor consumption and make some qualified guesses for how long the bottle will last and a lot of other statistics if we want.
We are going to 3D-print a rounded plastic housing for the next prototype using cheap load sensors (wheatstone bridge), a D/A converter, an ESP32 and recargable battery for the next prototype.