I spent a couple months in a house with a really humid basement which is not at all good for PLA filament. So I bought a dehumidifier. The dehumidifier had to be emptied twice a day. Ung, that’s robot work! I could buy a sump pump (technically a condensate pump) for around $50 whereas a small water pump, float switch, and power supply costs about $25.

The first prototype used a float operated reed switch to switch a motor on to pump the water up into a sink. Two major problems with that, the switch would shut off before the water in the vessel and tubing purged completely (causing it to backflow and create an endless loop) and the current to power the motor eventually fused the delicate switch. Whoops!

Let’s make it smarter!

So I added a relay to run the motor and I kind of knew I wanted to use some kind of micro controller to run the motor for a set amount of time so that I could track the volume of water pumped. I had a spare ESP8266 laying around and decided why not go the extra distance and have a webpage to check on the amount of water purged.

Arduino Source