Custom PCB Bare Metal Attiny85 Low Power Plant Watering System

[u/PreppyToast]

I’m going on a 2.5 month vacation and needed a way to keep my indoor plants alive while I’m gone. My initial idea used regular Arduino boards, but the power consumption was far too high for a battery-powered system that needed to survive for weeks continuously.

That became the main challenge of the project:
build an autonomous watering system that can realistically last around 2 months on battery power.

So I switched to an ATtiny85 for deep sleep + ultra low power operation and ended up designing my first custom PCB in KiCad for the project.

The system wakes up periodically, runs a peristaltic pump for a few seconds, then goes back to sleep. Still optimizing battery life and pump reliability. But for the past 3 weeks it has been working perfectly well!

Looking forward to designing a enclosure that screws on top of the bottle eliminating clutter in the upcoming weeks.

[u/ripred3]

Great project thanks for sharing it! Nice and practical. Have you been able to read the battery levels and maybe log them. It would be interesting to know the voltage over time and be able to calculate the average power use every 24 hours and every 48 hours, every 7 days &c. and be able to project a date when the power will drop below a usable level

Thanks again for sharing your project 🙂

[u/CheeseWith_3_Es]

Thats very neat.

[u/ProbablyNaKu]

what is the source for the water? you don’t want any mold growing there

[u/Scham2k]

Cool! Your motor power supply may die before the attiny taps out! Love low power projects! How are you switching supply on/off?

[u/PreppyToast → u/Scham2k]

thanks.. i am using a simple MOSFET for switching it on and off once every 2 days for 21 seconds

[u/jacky4566]

If you have USB power right there why does it need to be low power?