8 Station Sprinkler Controller (NodeMCU Lua) under $60
Base Parts List
- NodeMcu Lua v3 $4.50
- 8 Channel Relay Module $8.99
- ABS Case - 200x120x55mm $7.50
- 24VAC Power Adapter $14.82
- 24VAC > 12VDC $12.99
- 12VDC > 5VDC $6.99
Total - $55.79 per controller (before shipping/tax)
Optional Parts List
Note: Prices can be significantly lower on banggood (if you want to wait a few months), and you may find dedicated stepdown electronics for cheaper than the above DC converters.
After struggling with an inferior ESP8266/relay combo LinkNode R8 build, I decided to buy separate, dedicated relay and ESP8266 modules.
Unlike the LinkNode R8 build, these controllers have been completely solid - no resets, freezing or wifi issues since installing over a month ago.
Programming / HA Integration
My work-in-progress Home Assistant control: