After Step 1: General Decision, it is now time for Step 2: Create an irrigation and irrigation control plan.
We have identified three areas for us here:
- Things that are given and we don’t want to / cannot change
- Things concerning the control
- Things concerning irrigation
Given things
One of the main features is the possibility to control the irrigation with openHAB. This does not have to be exclusive, but start/stop, status and some basic settings should be possible. Furthermore we already have a driven well with a pump connected to it. The pump is in the basement and should stay there.
The control
After it was clear that the controller should be compatible with openHAB, we looked around a bit. The control system includes appropriate relays/switches, control logic, etc. We didn’t necessarily want to build that ourselves. Here we got hold of OpenSprinkler. openHAB Check: Yes there is a binding for it; Control Check: Yes there is. Either as an additional RaspberryPi board or as a complete solution. In addition, the power supply runs via a 24 AC transformer, which also supplies the valves and there is also the logic to control the pump with a suitable relay. We have decided to use the Raspberry version and we will add a housing which accommodates the transformer, the Raspberry and the pump relay too.
The irrigation
This is the most complex part (my wife did it :-)). Here you will find the appropriate information from the relevant manufacturers on how to plan the irrigation circuits, etc. - Use it!
The planning has resulted in a total of 6 irrigation circuits for the sprinklers, water sockets and drip irrigation. On the basis of the planning, the number of the individual parts required is determined. At the end we count 6 valves, 13 sprinklers, 2 water sockets, countless connectors and 250m of PE pipe.
Take a look around when ordering. The PE pipe must withstand the pressure of the water. Our pump can handle 3 bar. But the pipe for 6 bar was twice as expensive as the pipe for 16 bar. The connections are also much cheaper in the agricultural sector than at the irrigation specialists.
So much for planning. Step 3 is then the construction of the valves including connection to the pump and control.
So much for today. Happy gardening
Thomas