Archive for the node-red Category

It’s getting REAL!

Posted in ESP8266, Lua, MQTT, node-red, OpenSprinklette, Wifi on July 12, 2016 by asteriondaedalus


So the four-4-US$12 flow sensors have turned up.  The minimum measurable flow rate appears to be 1 litre a minute.  To put this in perspective Bob Hawke (ex Australian Prime Minister) sculled a yard glass (1.4 litre) of beer in a record (for the time) 12 seconds.

In comparison irrigation “emitters” tend to be in the ranges of:

  • 2,0 liters/hour – 1/2 gallon per hour
  • 4,0 liters/hour – 1 gallon per hour
  • 8,0 liters/hour – 2 gallons per hour

Now this will be per emitter so you will need around 8 times 8,0 liters/hour “emitter” in a line to get a 1 liter/minute flow by napkin scribbles.  A whopping 30! 2,0 liters/hour “emitter” will be needed to get a 1 litre/minute flow in a line.  Note, there may well be more than enough “emitter” to turn the paddle but that will depend upon the individual installations.

Not really a problem as the intention was to use this as a leak detector as the rate will be driven up but the leak, especially if your dog has dug up and chewed through a hidden hose, as evidenced by …


… mind you that one didn’t need a leak detector to find.

These sensors are advertised as low precision in any event so really not a problem.  So this won’t be of use to meter your water usage.

I am playing with the idea of higher precision flow sensors – to set time-versus-budget constraints  – but I will roll that in as a separate option as such a flow meter can likely go on the input rather than output lines, and as we are using MQTT the high precision flow-sensor can also be separate unit to the valve controller/line flow sensor.

All the signal integration will occur in the main host.

Hot damn!

Posted in MQTT, Networking, node-red, ODROID-W on January 3, 2016 by asteriondaedalus


node-red running on my odroid-w.

I have my old blackwidow working with a relay shield so I can drive sprinkler valves but I could not sort mqtt onto the older dopey wifi shield – just lazy.  So I will use node-red to drive tcp chatter to drive the relays and drive that with mqtt via the node-red.  That way I can integrate the board gently, using its current libraries.

Next experiments include, yes, sorting that static IP story.

Then getting mosquitto up and running.

There are a few warnings in the node-red install that I need address (upgrades of dependencies).  Otherwise I am looking at a thingybox the size of a matchbox.

Sensibly though I am looking at a small 220VAC-5VDC module to build the whole thing into a 3 Pin Plug Pack Case.


Yes, yes.  All would have been easier with a fresh download of the Jessi distro – since it comes with node-red.  But I do like the labour.

Still, the final version will be on a fresh Jessi distro so that I only need the mosquitto install to get this rolling.