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.
Description
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.
Nice! I have a similar switchboard (with direct Ethernet) in operation with a custom scheduler for >24month now.
As things happen I have a two level control mechanismn:
8 station sprinkler with scheduling based on temperature + rainfall
time scheduled ‘main valve’ that will in front of all 8 valves
In case a script goes notes the second circuit (triggered by a different protocol from a different machine) ensure that watering is only running between 9pm and 11pm.
/Edit/
Ah - and a cheap “hall sensor” flow meter will log the amount of water per circuit.
I built mine with an esp8266 and kept everything modular so I could swap out stuff if anything broke over time. I built it around using opensprinkler and it has been in operation since 2020. I highly recommend it!
After installing it I noticed an annoying bug… it was like a memory leak or something. After about a week of being powered on, it would become unresponsive. I posted about it to the opensprinkler forums and the developer made a modification that works to resolve the issue! Other than that single problem during the first two seasons it has worked well for three seasons and does watering adjustments based on the weather!
In Home Assistant there’s a HACS Integration for opensprinkler that works very well and I just discovered a HACS Frontend opensprinkler-card that allows very concise control of your controller via HA, here’s what mine looks like:
