Garden Irrigation, Pt 1

Some more background to my 'home assistant powered irrigation system' -- I'll write up a couple more articles as build progresses - I'm still waiting on some critical parts to arrive, like PVC pipe fittings and an Arduino Mega.

The Grand Plan.
The 2 main garden bed areas need to be automatically watered. The small 'hexagon' area contains 6 raised beds and a small central area. The main veggie patch (still being built. slow progress...) is around 20 beds. Later automation will include more smarts (hooking in my rainfall sensor, some buried gypsum sensors and soil temperature monitoring), but for now, the priority is to save on the 30-60 mins with a hosepipe in the evenings. Oh, and we're on tank (rainwater collection) water, so wastage is bad mmmkay.

The irrigation units themselves won't be 'smart' - All they need to do is send valve (relay) status, and respond to controls. I have an internal MQTT message broker, so a basic arduino + ethernet shield + 8 channel relay board does the small bed, and an arduino mega + ethernet (or an ethermega) + 3 8 channel relay shields the main veggie patch.

Sample arduino code is available on GitHub, (functions? who needs functions...) and yeah, it's not elegant. While it follows the syntax for the home assistant MQTT switch device, some of the defaults aren't the same, so I need to explictitly set them for now in the hass config. such as

switch:
  - platform: mqtt
    name: Hexagon bed 1
    icon: mdi:water
    availability_topic: status/hexIrrigation
    command_topic: control/hexIrrigation/valve1
    payload_on: "1"
    payload_off: "0"
    state_topic: status/hexIrrigation/valve1
    state_on: "On"
    state_off: "Off"

You can see here that I use status/hexIrrigation as LWT (so I know if the controllers on/offline) as well as the the relay state. I'm only using retain on the LWT, not the valves themselves. Power cycling the unit will (should!) reset back to all solenoids off, but I don't yet check and publish this, so hass may get confused if it loses comms. "Fixed in the next release" apparently :-)

I also want to integrate a flow sensor into each unit if possible (suspect I'm running out of digital IO on the small unit) to get an overall volume of water that's gone into the garden - fed, as normal into grafana.

I'll throw in another couple of postings (with pics) as the build progresses. but today I had an audience while working on the fence... (it will be fully netted to keep out the possums, pademelons and our hens)

Measuring empy space

If you've been following my recent posts on twitter, you'll be aware that I've finally got round to hooking up the MaxBotix rangefinders into our water tanks. So far I've done the main house tank and have sketches and buried duct ready to do the ones that water the garden.

Some more technical details here than I can fit in tweets:
* The sensors themselves sit through the roof of the tank. This involves drilling a 3/4" hole in the top of the tank and inserting the sensor from below, so you won't want to put it more than an arms reach from the access hole. The sensors I purchased have NPR thereads not BSP, so you may want to pick up matching nuts at the same time depending on local availability.
* I mounted some 6-way header pins on the sensor, and soldered the female end onto the cable so that it didn't twist as I tightened it up. All mounted in a 20mm conduit box on the tank.

Inside the shed, I'm just using a clone arduino with a wiznet ethernet shield (ebay/aliexpress) and a very basic sketch using the pulse width measurement from the sensor. As normal, it's available on GitHub for anyone interested. It pushes to an on-site MQTT broker (mosquitto) that's used to gather various sensor metrics and fed into home-assistant, where it also gets archived into InfluxDB for longer term plots

status/housetanksensor online

sensors/housetanks/depthbelowsensor 419

sensors/housetanks/litres 20762

I use the status for LWT messages, and the sensors has the raw air-gap measurement (mm below sensor - range is 300 -> 5000) as well as a calculated volume (see the arduino code for constants and calculation)

Importing into hass is as simple as

  - platform: mqtt

    name: House water tanks volume

    icon: mdi:water-pump

    availability_topic: status/housetanksensor

    unit_of_measurement: l

    state_topic: sensors/housetanks/litres

into the configuration.yaml

Next up, getting the irrigation system working...

Overlaying SLURM job timings on Grafana plots

As you may have noticed, I'm quite fond of Grafana and use it at home and work. One of the dashboards I have at work is the general state of our lustre filesystems, showing IO and metadata traffic, collected by a custom python script (I'm working on converting this to a real collectd python plugin) which stores the data in an influxDB.

I've since written a small python script that talks to our SLURM accounting DB, so that given a jobID, we can get the start/end times and overlay those using the annotations API. One minor niggle in that the API expects epoch milliseconds, and seems to be tied to the TZ of the browser that generated the API key.

however...

~$ annotate_job 2924399

Found the following job:

  User: bskjerven (pawsey0001)

  Cluster: magnus, Partition: workq, QOS: normal

  Nodes: 768, CPUs: 36864

  Start: 2018-06-11 17:23:22, End: 2018-06-11 19:54:44

Got something back - Annotate? (y/n) y

200 - Annotation added




and lo - 

weewx to home-assistant

At home I have a Fine Offset (this one branded by Jaycar) weather station that publishes to weather.two-fifteen.com via weewx (this is much simpler now I don't have to have the thing solar mounted in a field using a 3G dongle - at least the NBN is useful for some things) but I'd like to be able to use some of the measurements in home-assistant.

There isn't yet a direct plugin (spare time project anyone?) that I can see, but because I'm pushing the metrics locally to influxdb (have I mentioned I like drawing graphs of things?) for grafana, it's possible to use this in home-assistant via weewx-influx

Weewx config:
[StdRESTful]
      [[Influx]]
        host = localhost
        database = weather
        unit_system = METRIC

and on the home-assistant server:
  - platform: influxdb
    host:    203.0.113.88
    queries:
    - name: Outside Temp
      database: weather
      measurement: 'record'
      field: 'outTemp_C'
      group_function: last
      where: 'time > now() - 5m'
      unit_of_measurement: °C
      value_template: '{{ value | round(1) }}'

and lo and behold, you should end up with something like this:

which when compared to our nearest BOM observation site up the road in Grove correlates nicely (Grove is in a valley, we're at the top of a hill)

Don't count your chickens...

We have a cheapo Chinese incubator for hatching eggs. According to popular Internet postings, the calibration of the 'temperature setting' on the front vs reality inside isn't terribly accurate. Since I have a stack of 'Ruuvitags' (https://ruuvi.com) from their kickstarter, I decided to put combine them with Grafana so I could start logging the data and plotting trends.

First up, by default they broadcast an Eddystone beacon, so that you can simply see the data on a phone / tablet (via the Physical Web), however with Google dropping this feature, I decided to switch them to Raw mode which has a higher accuracy. This is done by simply opening the tag and pressing the 'B' button to toggle between Raw (LED blinks red) and URL (LED blinks green) mode.

I'm using a Raspberry Pi 3 as a Bluetooth receiver. Running Rasbian 9 (stretch) means that I get a recent (v 5.43) version of bluez which understands BLE. Although there's a Java app to push to influxdb, I'd rather use Python, so pip-installed the ruuvitag_sensor package.

Initially this worked 'OK', but the logs were full of noise on the listener, so I hacked up a quick script based loosely on the examples. When done, it was much cleaner than the original and was picking up more of the broadcasts.

Once again, trivial to add to influx with some templating