3 weeks ago I started new project as a gift for my father who live in the countryside. There he has well with electrical pump and elevated water tank for housekeeping needs.
He is a good hand (despite a bit old-schooled), and pumping is more or less automated using few scrap yard relays. But we had as low as –27 °C this winter so pipes were frozen few times. My idea was to create device that will keep both water level and temperature at desired level and be more safe, more reliable comparing to existing device he uses.
Due to workload in the office I was unable to create my “pumping station controller” fast and now I’m definitely late with heater (+5 °C behind the window). But for now the device is almost complete and I can write about its features:
- LM75A I2C Digital temperature sensor and thermal watchdog
- 2x A3212 Ultrasensitive Hall-Effect Switches for water level sensing using foam float with magnets
- 2x Atmel ATTiny13 MCU: one to watch sensors and control pump and heater, second for setting up LM75 during start-up
- 2x powerful Omron relays (230V/20A) to control load
I have a hope I’ll have a time to describe device in detail in next posts. For now you can take a look at visualized PCBs for the device I had designed before: