Tipping Bucket Rain Gauge for HT DN 110 pipe

thingiverse

This is a rain gauge based on the tipping bucket design. Rainfall is collected in the funnel, then fills up one half of the seesaw until the weight causes it to turn over, emptying the full half and putting the other half under the funnel. This variation tips each time approximately 2.5 cubic centimeters of water have collected in the top bucket. To save on material and printing time, instead of printing a full enclosure it's designed to be seated on top of a HT DN110 pipe (those are cheap, robust installation parts mostly used for sewage or rainwater). Measurement is done by detecting the proximity of the magnet inside the small side cavity of the seesaw that moves in front of a hall sensor glued to the small post. I've achieved stable detection with a 5x5x2 mm neodymium magnet and the low-cost A3144 hall switch. Instead of detecting the moment of the flip (sensor mounted in the middle), it's designed to deliver a steady signal while the seesaw is in position A, and no signal if the seesaw is in position B. Reading the input can be done periodically (or interrupt-driven) by a microcontroller. Insect-proofing may be beneficial, possibly by placing some gauze over the top and bottom of the finished unit.