Automate Irrigation, Updated

[papa]

            Automate Irrigation, Updated

    For openHAB 2.5.x & Otherwise I'm Updating This Thread

     "Automate Irrigation Based on Soil Moisture & Weather"

Perhaps like me, you've been interested in using OpenHAB & nodes to automate irrigation. In 2017, I created a Soil Moisture & Soil Temperature End Node that I wanted to use for Irrigation Automation.

Studying this, this, & this, I saw a good start on how I might irrigate my garden beds. These versions rely on weather data & (predetermined, but adjustable) watering periods. I wanted to include the weather data. However, instead of watering by timers, I wanted to use my soil moisture end node to trigger watering when the soil was drying out & stop when adequate moisure was achieved.

The following irrigation automation assumes one has these working: OpenHAB, MQTT, & computourist-style gateway. (I believe a ESP8266 wifi node could also be used without a gateway.)   I've used various versions of openHAB from OpenHAB2 to currently OH 2.5.4

Also assumed is a Soil Moisture End Node in the garden bed & something like a DHT End Node.  The DHT End Node will toggle a electrically activated water valve via a DC to AC solid state relay. The following also assumes an irrigation system (sprinklers, drip, ??) which includes water valves that open via AC electricity supplied by a 24 VAC transformer.

Clicking the node's User Interface or physical switch will (for maybe a minute) toggle the state of the valve open or closed before the state reverts to its state before the attempted switch.

This setup was successfully tested later in a real garden (see below). Initially it was tested successfully with soil probes inserted into a plant pot. When the pot's soil dried below the moisture threshold, the node triggered the relay to turn on an AC light.  Even with DHT sensor, push button, soil moisture sensor, & soil temp sensor running, the node had enough current to trigger the relay to switch on an AC device.

Originally, I thought I might mount the irrigation node on a stake in a garden bed & for protection, cap it with a liter bottle whose bottom has been removed. Later (see starting at this post), I installed the irrigation node in a sealed project box.

[papa]

        Automating Irrigation, Intro Continues

                Updated, April 17, 2020

This irrigation system (in each garden bed) can work with a wall-powered end node that includes at a minimum: soil moisture probe, DS18 Sensor to sense soil temperature , & a solid state relay which the node triggers with a 5 volt signal sent via a transistor. Such a node may also include optional DHT Sensor to measure outdoor temperature & humidity plus a push button. With help from OpenHAB programming, this node does it all: read soil moisture (corrected by temperature) & (in the garden bed) switch on an electrically activated water valve via the relay.

This system can also work (less effectively?) with a soil moisture & temperature end node powered by battery or wall power. A wall powered DHT End Node with relay near the water source & an electrical outlet could control the water supply to all beds. This version would be most effective in watering one bed. It could water more than one bed, but all beds would receive water based on one bed's moisture reading.

Start here for building the Soil Moisture Node (#DEFINE SLEEPY for battery) & for some needed openHAB configs. See this Oct. 2015 thread, for hints on building a DHT end node that sends 5 volts (via a transistor) to the relay that controls the water valve. Again for irrigation purposes, you could eliminate the DHT sensor & the push button from that DHT end node.  See this thread on building an Easier 3.3 Volt RFM69 Node. It even pictures an Irrigation Automation Node built this way.

To use this system for lawn irrigation, I'm thinking one could put a (protected) node that controls a solid state relay near each water valve & then put a battery powered (& protected) soil moisture node in the lawn zone that is watered by that valve.

[papa]

            Irrigation Node, Schematic

      << click on the pic for a larger view

        ^^ Updated March 24, 2020: Here is a schematic for an irrigation node that combines all functions. Please note this Irrigation Node schematic uses pins D6 & D7 for the soil moisture probes, instead of D7 & D8 in the schematic for the Soil Moisture End Node.

This updated schematic recommends adjusting a 0 ohm to 10 kilo ohm potentiometer to achieve "resistor 2."

[papa]

            Irrigation Node, Software (Updated August 30, 2021)

      Go here for the latest sketch for the Irrigation Node that combines all functions. Again (in case one wants to install the push button on D8), this version of the Multi-Choice End Node sketch uses pins D6 & D7 for the soil moisture probes, instead of D7 & D8 in the Soil Moisture End Node sketch.  With this version of the sketch, when radio connection with the Gateway is lost, the irrigation control node turns off the relay so the water valve will not be stuck on flooding the garden.  When a connection to the Gateway is restored, the previous relay state resumes.  With this version of the sketch, I inverted readings of the soil moisture probes so the values increase along with the amount of soil moisture.

        Necessary customization of the Irrigation End Node ...
Fairly early in the sketch, customize by UNcommenting these #DEFINEs:

        FAHR or CELS (temperature scale)
            HT (if using that sensor)
        BUTTON (if using button AND relay)
            ACTOR (if just using the relay)
        SOILMOIST

               DS18 & DS18B.

Configurations below assume NODEID 12. (Use no NODEID lower than 05.)

    Use the same ENCRYPTKEY as for your Gateway.

     At least for testing, UNcomment #define DEBUG
        UNcomment only one line with #define FREQUENCY according to your RFM69 radio's frequency
UNcomment #define IS_RFM69HW ONLY if your RFM69 radio has an "h" in its part number.

[papa]

        OpenHAB Weather Configs for Irrigation Automation
                Removed, April 18, 2020.

As I documented in this thread, for openHAB weather data, I am fairly satisfied with OpenWeatherMap (OWM). However, it lacks some things I valued that are no longer available from other services. I found some ways to supplement OWM.  OWM stations do not seem to track recent precipitation. Although I thought I had a way, so far I am not able to have OH grab recent amounts of liquid precipitation. So I disabled using that data for automated irrigation.

For automated irrigation, I had found a way (Dark Sky via the HTTP Binding) to get the probability of rain for today & tomorrow. The first 1,000 Dark Sky API requests per day have been free. However, when I looked up how to register currently for the Dark Sky API, I found on the Dark Sky blog:

By Adam Grossman on March 31, 2020. Today we have some important and exciting news to share [?? Argggh, #$%^&^%$#]: Dark Sky has joined Apple. ... What happens to our existing products? ... Our API service for existing customers is not changing today, but we will no longer accept new signups. The API will continue to function through the end of 2021.

So it goes with free access (with limitations) to weather data, it's up & then someone buys it & locks it down. It's too bad that NOAA weather data (paid for by our taxes) is not very accessible via an API other than from one of these on again-off again services.

Already registered people like me can access Dark Sky for another 1.75 years. Since new signups are not allowed, I will remove precipitation probability from the irrigation automation & no weather data will influence it unless I find another way.

[papa]

        More OpenHAB Configs for Automating Irrigation

    Before you do this post's instructions, be sure you make the openHAB configurations found here & here.

     From here, you should have created a Node12garden Thing.

Go to PaperUI/Configuration/Things & click on Node12garden.
    To add a new channel, click on the "+" in blue disc.

        In the Add Channel Window, fill the fields:
Channel type Text Value < choose type according to the item data type we want
Channel id Node12Channel00 < derived from the MQTT topic below
Label UpTime_12 < arbitrary, but create something descriptive
MQTT State Topic: home/rfm_gw/nb/node12/dev00 < where the node sends its uptime data

    <MQTT Command Topic: home/rfm_gw/sb/node12/dev00 < where openHAB requests node uptime data

        Click SAVE at the lower right.
^^ After the above is saved, Node12Channel00 (ready to link to an Item) shows under Node12garden Thing.

[papa]

        Add More Channels to the Node12garden Thing

              (click on the "+" in the Thing's blue disc)

        In the Add Channel Window, fill the fields & SAVE:
Channel type Text Value < choose type according to the item data type we want
Channel id Node12Channel02 < derived from the MQTT topic below
Label Gardn_12_RSSI < arbitrary, but create something descriptive
MQTT State Topic: home/rfm_gw/nb/node12/dev02 < where the node sends communication signal strength

        In the Add Channel Window, fill the fields & SAVE:
Channel type On/Off Switch < choose type according to the item data type we want
Channel id Node12Channel16 < derived from the MQTT topic below
Label Valve01_12 < arbitrary, but create something descriptive
MQTT State Topic: home/rfm_gw/nb/node12/dev16 < where the node sends on/off state

    <MQTT Command Topic: home/rfm_gw/sb/node12/dev16 < where openHAB commands ON & OFF

        In the Add Channel Window, fill the fields & SAVE:
Channel type Number Value < choose type according to the item data type we want
Channel id Node12Channel50 < derived from the MQTT topic below
Label Temp_Grdn12 < arbitrary, but create something descriptive
MQTT State Topic: home/rfm_gw/nb/node12/dev50 < where the node sends soil temperature data

   You should now have five channels in the Node12garden Thing.

[papa]

        More OpenHAB Configuration for Irrigation Automation

Go to PaperUI/Add-ons/Bindings & install Expire Binding. (This will help us know if our irrigation node is offline.)

What if you don't see the Expire Binding to install it?  When we first installed openHAB, it asked what package we wanted: Simple or Standard or Expert. We need to be in either Standard or Expert to see the 1.x bindings.  To fix this I believe you can edit \conf\services\addons.cfg.  Find the line that includes "#package = "  & change it to "package = standard" or "package = expert" (no "#" to begin & disable the setting). Save the edited file & perhaps restart openHAB.

     From here, you should have a Garden.items file in openHAB's conf/items folder with this item:

Number SoilMst_12 "Soil Moisture_12 [%s]" <humidity> { channel="mqtt:embedded-mqtt-broker:topic:mything:Node12Channel67" }

        Open Garden.items for editing & add these item entries:

String Node12UpTime "Gardn_12_Up [%s mins]" <network> (Nodes) { channel="mqtt:embedded-mqtt-broker:topic:mything:Node12Channel00", expire="3m,Offline?" }

String Node12Rssi "Gardn_12_RSSI (db)[%s]" <network> (Nodes) { channel="mqtt:embedded-mqtt-broker:topic:mything:Node12Channel02" }

Switch Valve01 "Valve01_12" (Valves) { channel="mqtt:embedded-mqtt-broker:topic:mything:Node12Channel16" }

Number Temperature_Node12 "Temp_Grdn12 [%.1f °F]" <temperature> { channel="mqtt:embedded-mqtt-broker:topic:mything:Node12Channel50" }

Switch GoodWaterTime "Good Time to Water ?" <sprinkler>

Number MoistThreshold12 "MoistLow12 [%s]" <humidity>

Switch Germinate12 "Germ 12"

        Added April 21, 2020:  Go to PaperUI/Configuration/Things/Node12garden.

    Click on the blue disc beside the channel Uptime_12.  Link it to the item Node12UpTime.  Continue to link ...

Link Gardn_12_RSSI (Node12Channel02) to the item Node12Rssi

Link Valve01_12 (Node12Channel16) to the item Valve01

Link Temp_Grdn12 (Node12Channel50) to the item Temperature_Node12

[papa]

        More OpenHAB Configuration for Irrigation Automation

     

       ^^ Download sprinkler.png to your openHAB's conf\icons\classic folder.

If you have not already, download soilmoist.scale to OH's conf\transform folder & edit it to reflect your soil conditions.  See this thread for more about this.

If you have an older irrigation.rules file, it could interfere. To disable the file, stop openHAB (OH), rename the file to irrigation.ruler & restart OH.

    From here, you should have a Garden.sitemap file in openHAB's conf\sitemap folder.

        To Garden.sitemap, add these entries:

Switch item=Valve01

Switch item=Germinate12

Text item=Temperature_Node12
Text item=MoistThreshold12
Text item=SoilMst_12

If you have your Node12 Irrigation Node built & connected to OpenHAB via the RFM69 Gateway & you display the Garden.sitemap in a User Interface (BasicUI ?) on a browser, Garden data & controls should display.

      Below, Three Ways to Use Irrigation Nodes

[papa]

        How This Irrigation Automation Works

On a User Interface sitemap, Valve01 displays the ON/OFF state of the node 12's relay/valve. Clicking Valve01 will briefly change its state, but Irrigation-pub.rules will soon regain control. Temperature_Node12 displays the soil temperature (useful for planting, but also tweaks soil moisture reading). MoistThreshold12 displays the moisture target number for Node12's garden bed. The user sets the parameters of this target in Irrigation-pub.rules. SoilMst_12 displays the number that represents the moisture level in Node12's garden bed.

How the Irrigation-pub.rules work: For normal operation, Irrigation-pub.rules alternates moisture targets between what the user determines is the lowest moist range and the highest moist range. For keeping just planted seeds moist, clicking Germinate12 ON overrides normal operation & leaves the moisture target at the highest moist range. When seeds have sprouted, you can turn off the Germinate12 switch. If soil moisture read is less than the set moisture threshold AND if it's an acceptable time to water (daytime, before & after the heat of the day), then a solid state relay opens a water valve to irrigate.

        Possible Adaptations

If you are putting a water valve & an irrigation end node in more than one location, add more items (adapting from the items provided so far) for those nodes & in Irrigation-pub.rules, add/adapt a Control_Valve02 rule for a second locations, etc for more locations.

Irrigation-pub.rules has log posting lines. To help monitor & debug automated irrigation, one can see the logs by entering log:tail in openHAB's Karaf console. OR in a text editor like Notepad++, one can open openhab.log & events.log in openHAB's \userdata\logs folder.

I'm interested to hear from those that try this Irrigation Automation via OpenHAB & how it worked for them.

[papa]

        Remote Control Irrigation

As long as I'm updating this project thread, I'll add a couple other ways to use Irrigation Nodes & their openHAB configurations.

For a Remote Control Irrigation, disable ALL rules that control the irrigation nodes & their valves. OpenHAB only runs rule files that end in .rules & are located in openHAB's conf/rules folder. So to disable (& yet preserve a rules file for possible later use), I sometimes rename the .rules part of the file name to .ruler. Otherwise I created a conf/Park folder & I sometimes disable .rules or other config files by moving them to the /conf/Park folder.

Display the Garden.sitemap in a User Interface (BasicUI ?) on a browser, Garden data & controls should display. There you should be able to monitor soil moisture & temperature. With all related rules disabled, on the computer screen or in a mobile app, you can click the Valve01 switch to remotely control irrigation.

        Next, Timed Irrigation

[papa]

        Timed Irrigation

Another way to use irrigation nodes is to use a rules file to turn their valves ON & OFF at optimum times & according to how much water you want to apply to an area. That rules file must be the only one controlling the node & its valve.

I used this approach last summer when my moisture probes became erratic & capacitive moisture sensors were no help.

    Garden-timer-pub.rules (2.75 KB)   << Download this file to openHAB's conf/rules folder.   Disable ALL OTHER files that control irrigation node valves.  See the last post for how I disable openHAB config files.

This version of Garden-timer-pub.rules irrigates near 8:00am each day & is timed for my drip irrigation to apply one inch of water to a garden bed. To enhance safety & reliability, it uses redundant commands with delays between. Customize these rules to your situation: Choose when you want to water & how much. Calculate how much time your irrigation needs to apply that much water. Change the fail safe rules to make sure the valves are OFF outside of chose irrigation time.

Display the Garden.sitemap in a User Interface (BasicUI ?) on a browser & Garden data & controls should display. There you should be able to monitor soil moisture & temperature. However, when you click the Valve01 switch, it will change state only briefly. For Garden-timer-pub.rules now controls when irrigation happens.

[papa]

        Irrigation Automation

        Based on Soil Moisture

Irrigation-pub.rules (2.92 KB)     

       ^^ Download irrigation-pub.rules to OH's conf\rules folder. Early in the file, edit moistThresholdHi & moistThresholdLo values to match your node's interaction with your soil. moistThresholdHi should be a value you measured at the high end of nicely moist (below WET).  moistThresholdLo should be what you measure at the low end of nicely moist (just above DRY).

     Disable ALL OTHER rules files that control irrigation node valves so they do not interfere.  See this post for how I disable openHAB config files.

        Next, How Irrigation Automation Works & Possible Adaptations

[papa]

        How Irrigation Automation Works

On a User Interface sitemap, Valve01 displays the ON/OFF state of the node 12's relay/valve. Clicking Valve01 will briefly change its state, but Irrigation-pub.rules will soon regain control. Temperature_Node12 displays the soil temperature (useful for planting, but also tweaks soil moisture reading). MoistThreshold12 displays the moisture target number for Node12's garden bed. The user sets the parameters of this target in Irrigation-pub.rules. SoilMst_12 displays the number that represents the moisture level in Node12's garden bed.

How the Irrigation-pub.rules work: For normal operation, Irrigation-pub.rules alternates moisture targets between what the user determines is the lowest moist range and the highest moist range. For keeping just planted seeds moist, clicking Germinate12 ON overrides normal operation & leaves the moisture target at the highest moist range. When seeds have sprouted, you can turn off the Germinate12 switch. If soil moisture sensed is less than the set moisture threshold AND if it's an acceptable time to water (daytime, before & after the heat of the day), then a solid state relay opens a water valve to irrigate.

        Possible Adaptations

If you are putting a water valve & an irrigation end node in more than one location, add more items (adapting from the items provided so far) for those nodes & in Irrigation-pub.rules, add/adapt a Control_Valve02 rule for a second locations, etc for more locations.

Irrigation-pub.rules has log posting lines. To help monitor & debug automated irrigation, one can see the logs by entering log:tail in openHAB's Karaf console. OR in a text editor like Notepad++, one can open openhab.log & events.log in openHAB's \userdata\logs folder.

I'm interested to hear from those that try this Irrigation Automation via OpenHAB & how it works for them.  What tweaks have you tried?

[papa]

Mar 16, 2017 1:07:16 GMT jimkernsjr said:

I like your irrigation system you develop. I have one I developed, completely standalone, that ran on the RPI, with the "PiHat Relay Board". It's completely written in Python, PHP, and MySQL (which is why I'm somewhat Biased). I just dont know how I feel about OpenHAB controlling watervalves over a wireless network - this scares me a little. My software has been working flawlessley since about 2014, but has a small voltage drop problem I discovered. If you tax the CPU with a valve open, the PI can hang up, and you know the rest. Which is why I say be careful! My lawn got a good watering that weekend!I've since used a port expander, Darlington chip, and offloaded the relay power so it's not being powered by the PI. It also now has a watchdog system too! I've added MQTT to it and make it check in with OPENHAB every 5 minutes, or OpenHAB shuts it down.  The whole project is great, and Its still better than most I've seen featurewise.  It's just not as polished, as you can see (times in "raw" format, etc).  I just added zones 5-8 for this year because I added irrigation to my back yard.  If it's something anyone has an interest it, I'd love to share it - maybe someone has the time to take it further than I ever did.  It would be easy to integrate further to openhab, you could just have Openhab cancel the watering if your soil is already damp enough.

But anyway, honestly, I'm more scared of water than electricity...some of the biggest natural disasters were water, not fire. Be careful with it!

     

[papa]

Mar 16, 2017 1:35:15 GMT papa said:

jimkernsjr, you raise some safety, reliability issues that I've had in the back of my mind.

I will be doing low flow drip irrigation, not heavy flow sprinklers. For my irrigation controlled nodes, I probably will use Buono Uno's plus shield. Each garden bed will have a soil moisture probe reporting to the node so that will cancel irrigation when moisture reaches in the middle of a good zone for the plants. I'm also thinking of using the expire binding to cancel irrigation if the soil end node loses touch. I'll probably also have OH message me if soil moisture somehow gets above the set moisture threshold & the valve is still on (stuck?)

I'll take to heart your warning that the node's signal to the relay could get stuck on & consider a separate power supply for the relay. I'll also take to heart your concerns about wirelessly controlling the irrigation valves.

It will take me a while to build irrigation piping, etc. May be wise to start with one garden bed that matters less & experiment with it.

[papa]

Apr 3, 2017 20:43:50 GMT papa said:

I've aimed to make this Irrigation Automation as reliable as possible. jimkernsjr raised the possibility of flooding above.

With the current version of the sketch, when radio connection with the Gateway is lost, the irrigation control node turns off the relay [within a minute] so the water valve will not be stuck on flooding the garden. When a connection to the Gateway is restored, the previous relay state resumes [within a minute].In the txRadio() function, I added this line (it parallels how computourist has DEBUG output "No Connection"):

if (retx) digitalWrite(ACT1, 0);  // Turn off irrigation ACTOR if node loses connection with Gateway
To test, I simulated the conditions of lost connection & resumed connection & confirmed that the first turns off the relay & the second turns it on again (if moisture is needed).

[papa]

Apr 26, 2017 21:44:28 GMT papa said:

I continued to work on this Irrigation Automation project. Having 3 raised garden beds, I built 3 each of the following: 1. Moisture sensor  2. Drip tubing grid 3. Moisture & temperature sensor node controlling a solid state relay to activate a 24 VAC solenoid valve. I'm in the process of building the PVC piping & electrical wiring (in conduit) running to each bed.

BTW, I tested the nodes in each outside garden bed & confirmed that they communicate with my second floor gateway.

        Moisture sensor construction is updated in this post.

Note: #1 started as 2 stainless steel skewer lengths stabilized in 2 synthetic wine corks fastened together.  As noted above, the stainless steel became problematic.  Also capcItive soil sensors did not work for me. For probes, I will now use the copper center of coax cable. See this post for more details.

See this June 30, 2020 update: Moisture sensors from coax work moderately well but might be improved.

[papa]

        Protective Project Box

           For Irrigation Nodes

     

             ^^ For my outdoor garden irrigation project, I bought these pretty big (200mmx155mmx80mm) waterproof project boxes. As of April, 2020 we must wait for them to arrive from China. In the pic, you can see half of the 10 possible circular ports.  They are a rubbery plastic which one can puncture to pass in wiring from the outside.  So far they have kept inside components dry in rainy weather.  Into this box, I fit a duplex surface mount electrical outlet, an Arduino compatible with RFM69 radio, a 24 VAC power adapter, an SSR-25 DA solid state relay, a 10 kilo ohm potentiometer, & (for the Arduino compatible) a 5 volt power adapter & USB cord.

For 3 years so far (2017-2019), the project box has successfully protected the electronics.

Update, June 30, 2020: However, this year one box flooded & killed the Arduino.  See this post for my current solution.

[papa]

May 8, 2017 23:50:02 GMT papa said:

        After weather & other delays,
I finished most of the plumbing & wiring (via conduit) the electrical outlets to the 3 raised beds. (No leaks. Outlets worked.)

Trenches for pipes & conduit are mostly filled in.

        Still to do:
- Connect the electrical water valves to the drip grids.
- In the waterproof project box for each bed, install the node plus its relay, moisture sensor, & temperature sensor.
- Wire the valve power supply through the relay.
- Button up the project box.
- Tweak the Arduino & OpenHAB programming based on real world experience

The "to do's" were completed. Each fall the water valve & electronics are removed to storage & reassembled in the spring.

[papa]

Jul 22, 2017 16:19:04 GMT papa said:

                        Update on the Irrigation Automation Project

            Weeks ago, I finished the to do list:
- Connected the electrical water valves to the drip grids.
- In the waterproof project box for each bed, installed the node plus its relay, moisture sensor, & temperature sensor.
- Wired the valve power supply through the relay.
- Buttoned up the project box. (See the project box in this post.)
- Tweaked the Arduino & OpenHAB programming based on real world experience.

The "tweaks" included correlating the moisture sensor readings with what is moist for a garden plant, especially the low & high sides of the moist range. These readings are probably not exact, but are good enough to keep soil moisture in a healthy range. In the OpenHAB irrigation rules, I use cron programming which sets moisture threshold at the low end of moist for about half of a week & at the high end the other half of the week. This cycling of moisture levels is supposed to be good for plants & encourage deep roots.

Moisture sensors are still working. Their wiring & programming alternates the current powering the sensors, which so far seems to avoid electrolysis & eventual failure. [This became a problem in 2019 & for 2020, copper probes will be used.]

The node programming turns off the relay & water valve whenever the node loses contact with the gateway. I've never had a flood due to a stuck valve.  So far the project boxes protect the electronics from moisture & dirt.

With some effort, I believe before winter, I can remove & store the drip grids & electronics.

This project (my biggest to date) was a lot of work over a long period. However, I am very pleased with the results.  I love drip irrigation which is gentler & more efficient than alternatives.  I definitely use less water. The electronics & programming are working well.  It's a kick to hear the valves click on & the garden "waters itself."  The plants are healthy & productive. I can [generally] focus on picking, eating, & giving away the garden produce.    32 square feet of raised beds is providing more than my wife & I can eat so friends are also benefiting from the bounty. So far I am more pleased with the results than I anticipated.

In fact before each winter, I have removed & stored: drip grids, electronics, & electrically controlled valves. I disconnected the water from a home spigot & blew water out of the PVC lines. In the spring, I reassemble.

[papa]

Aug 19, 2017 3:21:48 GMT papa said:

A rainstorm just watered our area AND my garden.

It was cool to watch the moisture values increase in the OpenHAB app on my phone.

Now that OpenHAB will message me if the garden nodes' gateway is not connected, that is one more assurance that I can make sure the garden gets the right moisture.

Note: The thread for "OpenHAB will message me..."  has been updated.

[papa]

Oct 16, 2017 20:45:55 GMT papa said:

        Update on My Automated Garden Irrigation

After a summer plus some fall operation, I am still pleased with my automated Garden Irrigation. Generally, the circuits & code have kept the moisture in my three raised beds in plants' ideal range (alternating between low & high thresholds in that ideal range). Between that & my drip irrigation grids, I am using less water, the water is applied more gently than before plus less water & soil bounces up on the plants. As I coded, the electrically activated water valves turn off when its node loses connection with the gateway & resumes when the connection is restored. It was nice to let the system mostly handle watering the garden & I could focus on other things.

I had a couple smaller issues with getting reliable moisture readings: A) From time to time, I need to re-seat the moisture sensors: lift them from the soil & reinsert them. This usually restored the accuracy of the moisture readings.  B) For one node's moisture sensor, I had used a tarnished connecting wire.  Cleaning it with steel wool fixed this. (Soaking the bared wire end in vinegar would probably be even better.)  ...

[papa]

Oct 17, 2017 2:01:57 GMT brump said:

Oct 16, 2017 20:45:55 GMT papa said:

Again, I am pleased with how this system works.  I expected more problems.  Apparently electrolysis on the moisture sensor probes is avoided by powering one probe, turning off probe power during the node's pause between sends, then powering the other probe, pausing power, etc.

Hi Papa, for sensors, I have tried to use 316 stainless steel bars. Probably will not have problems with oxidation.

Another important point is don't leave exposed the electrical connections between the material and the conductors. Liquid insulation tape solves this problem well.

Brump

[papa]

Oct 23, 2017 1:40:32 GMT brump said:

Oct 17, 2017 17:31:49 GMT papa said:

papa: I'm not sure I understand your "don't leave exposed the electrical connections between the material and the conductors." My wires solder to the skewers above the soil and the soldered areas are covered with heat shrink insulation.  I use liquid insulation in other situations & like it.

I believe I need to re-position the moisture sensors occasionally because the dense soil shrinks away from the probes. In most cases, that restores accurate readings. One time for the one node, I had to polish the moisture sensor's wires where they connect with the node sockets.

    I say that because oxidation in the wires increases the resistance at that point. Regarding heat shrink, always prefer the model with internal glue. With no glue plus rainy days or large water accumulation, moisture ends up migrating to the wire and causes oxidation.

When liquid insulator is properly applied, the connection can be immersed in water, the wire does not risk of exposure.

papa:  Good to know.  Thanks.  So far, my oxidized wires were inside the project box and inserted into the node's sockets.

Thanks, brump, for checking in with suggestions. How is your irrigation project progressing?

    My irrigation project is in the same way. Only with timer and solenoid to open the water flow. After February I intend to replace my sprinklers with retractable models, with that I will have to open the grass and so prepare to install electrical pipes to install the humidity sensors.

You're making great progress. Congratulations!   papa: Yes, thanks, the progress has been very satisfying.

[papa]

Oct 23, 2017 16:23:20 GMT brump said:

Oct 23, 2017 1:40:32 GMT brump said:

papa: Good to know. Thanks. So far, my oxidized wires were inside the project box and inserted into the node's sockets.

You can use dow corning 4 (DC 4) on the connectors and wires inside the box.

[papa]

Oct 23, 2017 19:21:30 GMT papa said:

Thanks, brump. You are a treasure of information.  Heat shrink tubing with a glue lining looks promising for achieving a tighter seal in challenging installations like outdoors.

I had never heard of Dow Corning 4 Electrical Insulating Compound. It looks interesting, but from what I read, DC 4 might prevent the bare wire ends from electrically connecting to the node's female sockets (as I need).

I believe those bare wire ends may have been stripped of insulation & exposed long before I used those wires. Thus the oxidation could have started before I attached those wires to the moisture sensor. I have no trouble with the the nodes in the other two garden beds. I bared the ends of those two nodes' moisture sensor wires not long before I inserted them into the node's female sockets.

[papa]

            Irrigation Automation
                 A Current Update

For openHAB 2.5.x & based on 3 years of real world experience, I have now updated this Irrigation Automation project.

I just reinstalled & activated electronics in the garden project boxes so I can plant for the 2020 season.

I look forward to testing the current programming & improved moisture sensors (made of coax cable sections).

        Stay tuned.

[papa]

        Irrigation Automation, Updated

            Project Enclosure Changed

For 3 years the project box in this post worked OK.  Then this year (2020) in heavy rains, one box flooded. So I took a new approach.

      << Forum members, click on pics for larger view.

       ^^ As in this picture, I mounted project components higher on a garden bed's corner post. This should keep things above where water may collect.  I also believe my RFM69 radio communication is stronger this way.

      

       ^^ As in this pic, I cover mounted components with a 13.2 gallon plastic waste container. I put a weight on top. The containers were about $10 each at Walmart. Components fit tightly in the previous project box & were tricky to work on. It's easier to remove the waste container & work on things. I hope this approach will keep components dry & easy to work on.