As I moved into a new apartment, I started to think about gardening again – hopefully this will be my new hobby again.
So as a good gardener I quickly realised maybe the most important thing for a green garden is the WATER.
okay, but I don’t really want to spend too much for that however I need to water my lawn/my flowers properly.
I used RPI based Opensprinkler setup few times in the past – and I was pretty amazed by the result, however it’s need the custom built PCB from rays hobby shop + a dedicated RPI, so overkill, right ? 🙂
However, Opensprinkler has a nicely built SW straightforward GUI + lot’s of integration possibilities and app for both Android/IOS.
I inspired by this setup as well – however I hate to build dependencies – so the showstopper was the HomeAssistanat in this case, I wanted to build something which is capable to work without external dependency.
+ I don’t really wan’t to spend’s a lot to build something which is temporary – so I continued to search for a more feasible alternative.
I ended up with this:
- Wemos D1 ESP8266 based board / any other NodeMCU will do it
- luckily Ray released his version of OSBee code for the community, so we will use this
- some modifications still required because ray used latching type Valves and I would like to use regular 24V AC Valves
- here is used sketch: https://github.com/akomakom/OpenSprinkler-Firmware-CustomLatch
- all credits goes to RAY and AKOMAKOM I just fine-tuned couple of things for my setup:
- Here is my code version:TBD
Purpose
This fork contains modifications to the original firmware to support a non-standard, oversimplified hardware configuration. It is meant to drive regular AC without an I2C expander, via relays, directly with GPIO pins, with minimal investment. A small number of valves is supported (number of available GPIO pins minus 1).
Some fancy integration would be nice – HomeBridge in this case, I can control my sprinklers via SIRI, how cool is that right? 🙂
Hardware
- ESP8266: Wemos D1 Mini or similar
- Relays: An optocoupler 2 relay board (2 SPDT relays are used as an H-Bridge)
- 5V Power: To power the ESP (I’m using an old PSU )
- 24V AC: valve-appropriate voltage. (My whole system works fine from a 24V AC-AC transformation 10VA)
Obviously some wires, connectors and enclosure would be helpful.
Limitations
- No display, no buttons, no expander, no booster, no RTC.
- Only WiFi access
- Up to 6 valves (I’m using only 2 now).
Logic
The logic is slightly different from the standard Opensprinkler „Latch” type:
The prototyping:
The final assembly:
The power supply box: 24V AC adapter + the tiny 5V Dc PSU for the ESP
This is the native Opensprinkler WEB GUI – running on a TOP of ESP8266, awesome, right ?
In addition to the native HTTP GUI – or you could use the native Android/IOS app –
I did a HomeKit integration to be able to control the Valves through any Apple ecosystem.
I used a Homebridge and the open sprinkler plugin and the Homebridge exposes the Valves to the IOS HomeKIT.
pretty neat, right ?
System is running:
Valve2 running 
Valve1 running HomeKIT integration