The sensors are from AZDelivery, these ones. They are connected to an arduino nano which reads the capacitance values and sends them over to a raspberry pi 5. The raspberry pi 5 is connected to a few other sensors (CO2, particle counter, air humidity and temperature all from Sensirion), and there is a 7-inch raspberry pi display that the pi writes images to. I was making a home air quality station but I decided to place everything around the pumpkin instead for now, to see if I could get something interesting out of that. But, so far most of them have not been practically useful.