Open sprinkler installation

[Anonym]

Open sprinkler installation, 40 stations (24 active), Gardena irrigation, garden pump, pool control, Homemetic integration, weather station, radio remote control, etc

In the past few nights I have installed the entire irrigation electronics and electrical engineering installation cleanly in the IP67 box and finally said goodbye to the flying wiring.

The irrigation project started 4 years ago (2017) with initially one OpenSprinkler Main Controller V2.3, which still does its job today. However, this now has 2 expansion boards, so a total of 40 station outputs, of which only 24 are currently used. I installed the second expansion board as a “reserve” because new irrigation zones are constantly being added.

The following are controlled via Open Sprinkler:

garden pump
10 x Gardena square pop-up sprinklers
2 x Gardena sprinklers
3 x Balcony Box Irrigation
2 x plant troughs
1 x underground lawn edge irrigation
3 x irrigation lines for a total of 48 shrub plants
3 x valve controlled water sockets
1 x pool filling
1 x pool filter pump (prepared)
1 x pool chlorine generator (prepared)
1 x outdoor lighting / outdoor socket (planned)
Hardware:

OpenSprinkler v2.3
2 x OpenSprinkler expansion board
3 x DIN rail relays 12V
9V plug-in power supply
IP67 housing 60cm x 40cm
8 x Gardena triple valve boxes, 3 of which are equipped with 7 valves each (3 box as a reserve)
8mm, 20mm, 25mm and 32mm PE lines (depending on the flow rate, main lines in 32mm)
Bechwand pool, with filter system and choir generator (salt water electrolysis)
Special features

All electronics mounted in the basement. From there, 5 cables with 7 wires each lead to the valve boxes (6 valves are controlled per cable + 1 x common, i.e. 2 Gardena 3-way valve boxes per cable).
3 the OpenSprinkler Outputs drive 12V relay coils directly (visible in photo). The 3 relays each switch 2-pole (reverse polarity protection) the following 230V devices: fountain pump, pool filter pump, pool chlorine generator.
Well pump is of course configured as “Main 1” in OS.
Filter pump is configured as “Main 2” to ensure the filter pump is always running when the chlorine generator is on. The well pump is already switched on via the relay, the filter pump and chlorine generator are not yet connected to the relay because the power cables of the devices at the pool are not yet routed through the basement wall. The idea is that the filter system including chlorine generator over OpenSprinkler times, typically 3 hours a day, when there is heavy bathing and/or high temperatures the pool needs more chlorine. Next project: waterproof cable duct for the pool equipment through the basement wall.
Integration into home automation: Home control center (Homematic) sends HTTP requests via script Opensprinkler and uses it to control the following OpenSprinkler Commands: switch individual stations on/off (signals from the remote control)
Start irrigation programs (signals from the remote control)
Rain delay (signal from weather station)
Regarding the remote control: It is simply extremely practical when you are working in the garden, need water from the water hose from time to time and then simply have the small, handy remote control in your trouser pocket with which you can activate the garden pump or individual irrigation circuits or sometimes can start entire irrigation programs. Of course you could also use the smartphone with the OS app for this, but the touchscreen is difficult to operate with soiled fingers or gardening gloves. It is a Homematic remote control, it sends to the Homematic control center in the house, where a script is started, which sends the corresponding Http request to the OpenSprinklercontroller sends.
Rain delay through weather station: The rain delay through the weather station works in a similar way to the remote control. The weather station is again a Homematic component. When it starts to rain, the station sends to the Homematic headquarters. A script is started there again, which sends a corresponding Http request OpenSprinkler sends, which activates the rain delay in OS. If it stops raining, further communication between the control centers takes place: From the end of the rain, the rain delay in OS remains active for a further 12 hours. There is also an OS API command for this. Although OpenSprinker can receive weather data from the Internet, these are not precise enough to determine whether it is actually raining on your property or whether the rain cloud is passing by. Without its own rain sensor (in my case its own weather station) it can happen that the OS waters even though it is raining. Then the neighbor is already in front of the door and points out that you have switched on the lawn sprinkler despite the pouring rain. In order to avoid this embarrassment, you need your own rain sensor on site.
Pool filling via OS and garden pump: Time control is required to completely refill the empty pool. In my case, the pump has to run for 14 hours. After that, OS shuts off the pump, preventing overflow. In addition, the pool must be refilled in the evening when there is strong sunshine (evaporation), for which the pump and valve must be activated for 10 to 20 minutes, depending on the outside temperature. The water inlet to the pool is simply a 25mm PE pipe that is connected to one of the Gardena valves and ends on the other side at the edge of the pool. It would also be desirable to have a level sensor by the pool to fill up exactly to the target level, the current solution only calculates the duration of the pool filling based on the outside temperature during the day, which can lead to deviations over several days that have to be corrected manually.
Valve-controlled hose connections: Until recently, Gardena simply connected the water sockets to the water supply lines to the valve boxes. To draw water from the cans, all you have to do is connect a garden hose to the water sockets using the Gardena coupling and switch on the garden pump. All valves should be switched off in order to have full pump pressure on the connected garden hose and not to let any sprinklers etc. run at half pressure at the same time. This was easy to configure in OpenSprinker by naming a free station as “hose” and configuring it together with “Main 1” (= garden pump). You don't even need to use a "real" station connection in the OS controller for this, but you can configure more stations in the OS configuration menu than are actually available. I call these physically non-existent stations “virtual stations”. “Hose” can be a virtual station whose function is simply to switch on “Main 1” (=garden pump) without any valve being active. The water is then drawn from the water socket between the pump and the valve box through the connected garden hose. Another “virtual station” I call “pause”. It doesn't drive a main, so the pump is off. The "Pause" station is only used to give the pump a break during long watering programs, or to build a pause into a program for any other reason, or to provide a pause in manual watering.
Back to the topic: My hose connections (water sockets) were previously connected directly to the main water pipes between the pump and the valve box. This is very practical because you don't need valves for the water sockets and you can still control a connected hose via OS. However, this cheap solution also has disadvantages: If you forget to remove the hose from the water socket (and there is no other stop device in the garden hose), the hose is also active as soon as OS starts an irrigation program. So, in the evening it's home, you retire, believing that the watering program will do its job, only to find out later that the lawn wasn't watered at all because all the water ran out through the garden hose for hours. It becomes particularly difficult when other family members connect garden hoses without realizing why the garden hose must be removed before starting the watering program. In addition, there are situations in which one would like to consciously include a garden hose in the watering program. For example, this is the case when new plants have been planted that are to be temporarily watered particularly heavily, so that a connected garden hose ends on the plant. This does not work if the connected garden hose disrupts the entire watering program because some of the water is constantly draining through it.
All of these considerations recently prompted me to control all three water sockets with their own valve. Now I no longer have to worry about whether a hose is still connected that someone in the house accidentally left there. The watering program is no longer affected. In addition, I can switch on water sockets at any time, for example to water a plant specifically with a garden hose. Another application example is the garden shower, which is permanently connected to the water socket on hot summer days and can be activated for just 3 minutes using the radio remote control (see above). Disadvantage of the valve-controlled hose connection: Costs for the additional valves, lines, cables, etc. and occupancy of one OS station per water socket. You could also connect all water sockets electrically to an OS station, or supply all water sockets together via one valve, but if so, then right: now I want to be able to control each water socket individually and via its own valve.
Next plans:

Connection of the pool equipment (filter pump and chlorine generator) to the relays in the basement, also via OpenSprinkler to be able to steer. In addition to the cables that have already been laid, the power supplies for the pool equipment must also be routed through the outer wall of the basement in such a way that no groundwater can penetrate the basement through the boreholes.
Level sensor at the pool to prevent the pool from overflowing or insufficient filling, as well as to be able to remotely monitor the filling process. Approaches to a solution: capacitive level gauge, ultrasound, float switch, electrical connection through the (salt) water in the pool. I tend to use a capacitive level gauge, possibly an additional float switch to precisely determine the final level. In contrast to the rain barrel, the problem with the pool is that you bathe in it, which creates wave movements and thus fluctuating sensor values.
Window boxes: I use Lechuza window boxes. They are expensive, but they look good and have a water reserve with an overflow below. The flower boxes are filled with water daily via thin, transparent hoses that lead from the valve box on the house wall up to the balconies and windows. 2 to 4 minutes are enough for all boxes together, which are filled together via a valve and then all overflow from the overflow. I adjust the watering duration so that even the last box overflows, so I know that they are all full. Too much water doesn't matter, that's what the boxes have the overflow for. The plants in the boxes "pull" their water, as needed, over the porous stones in the bottom of the box. So the soil in the boxes is always only moderately moist, no matter how much water is pumped into the reservoir of the boxes. When this irrigation circuit is running, water drips down from the flower boxes all over the house. I've thought about putting a return line on each box for the spilled water to keep it from dripping, but that would be tricky to put in place and heck it just drips.
More watering zones: There is always something new that needs watering: vegetable patches, flower pots, unwatered hedge bushes. To do this, I installed the second OS expansion board in the new electronics box today. No zone is occupied on the new board yet, but that will definitely come.
A stronger pump: There is so much watering that the programs run for several hours a day until the 24 stations are finished. If the pool is then filled for hours, the pump runs continuously on hot days. If that is no longer enough, a more powerful pump is needed, possibly a second well. This would fill the pool faster, run more sprinklers at the same time, etc. I'm thinking about switching from the current suction pump to a submersible pump, but I'm not sure yet. The pump always pulls a few air bubbles, but hopefully that shouldn't happen with the submersible pump. Any ideas, suggestions or recommendations on submersible pumps?
So much up to here. There are probably more details that I haven't noted yet. Maybe more later. I can post more photos if interested. But now I've earned the AD converter...

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