A sprinkler controller built from a 555
Self-initiated project
The problem
An automatic sprinkler needs a timer. The obvious answer is a microcontroller, which is more capability, more cost and more to go wrong than the job requires.
What I did
Start from the criteria rather than the part. A bistable 555 circuit, prototyped in TinkerCAD, does the job with components available from any general retailer.
The result
A robust controller with almost nothing in it to fail. Published as a walkthrough, because the method is more useful than the circuit.
- PART
- A sprinkler controller built from a 555
- MATERIAL
- NE555, discretes
- PROCESS
- Breadboard, TinkerCAD
- YEAR
- 2026