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Home Auto - Playing Around with EmonCMS, MQTT, Node Red and the Node Red Dashboards


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Here's a page of my Emon that shows what's happening in detail (Things I am monitoring as I see fit, I add/remove/play here)... It is all pi based, being fed from custom software I have written in Node Red... If anybody is interested, I will post a few more pics of the node red dashboards when I get a chance... The pi is controlling somewhere around 30 to 40 wifi switches, doing everything from irrigation to lighting to grey water recycling to fridge, washing machine, dishwasher, deepfreeze, to multi element geyser control(to name but a few)......(Oh yes... Also integrated 433mhz remote fobs to control selected lighting at will)...


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Hi @Joe Moer,

Here is the main info screen I use on the cell phone, a little truncated, but its just status lights that are cut off at the bottom of the page:


And a similar content, but different layout when viewed on PC:


The setup has got quite involved, with parameters specifically written for each "main" piece of kit on the system:


Certain pieces of kit are SOC controlled, others are controlled by availability of sunlight power, others are solar timed and more often than not, a combination the available options is used to get the best/most out of what energy is available at any given moment - There are also a couple of cute little things I have incorporated to keep the loads below the nominal 3kw mark - This isn't out of necessity, but I am not wild about inverter wear and tear mounting up (It can handle 5kw with a 10kw surge, plus I have a 2nd that I can parallel it with if I need to, but why should I, if I can keep loads in tow automatically?).. One of these tricks is that when a heavy load turns on by available power, other loads are turned off... ie when the dishwasher hits the 2kw heating cycle, deep freeze, air compressor etc are barred from starting and if they are running, they are shut down immediately until the high demand is over....

Here below is a fairly complex parameter screen, namely for the DeepFreeze - It has 3 temperature bands based on day/night and excess power availability, with the option of offsetting day and night times depending on your needs, it also takes care of power failures, checking the SOC and economising power usage when there is no mains power to fall back onto by shifting to the "night temperature" bandwidth... (Oh yes, the system is both Lead Acid and LiFe friendly, with control being selectable from either SOC or Battery Voltage governing...):




Amongst other features (beyond just turning on fridges, pumps, compressors and washing machines etc) that I have written into the system are:

  • Luminescence detection (used for determining maximum solar power availability on the fly)
  • SOC control based on reported SOC from inverter OR direct SOC from the Pylon batteries(with 4x Pylons in the system, SOC switching can be fine tuned to within .25%)
  • Monitoring of Inverter Output and the ability to warn users of heavy usage
  • Switching of Inverter modes, be it charger source or inverter mode proper remotely
  • Setting of utility charge current remotely
  • Automatic security lighting based on SOC and solar timers
  • Water preheating based on excess power availability, this heated water is then fed into gas geysers for final heating if required - 8 stage multi load purely resistive element, temperature and power availability controlled...
  • System messaging and control via Telegram alerts to control remotely as well as be notified of urgent system items.
  • Telegram control of external Lighting
  • Control of auto start diesel generator - This only starts when there is a mains failure and batteries are nearing depletion - The system then puts the inverter into eco mode, switches to utility and solar charging, sets the charge current, then monitors SOC until it is within bounds... It then shuts the gennie down, switches to battery, sets charge/inverter/everything back to "normal" mode... (All modes, currents, SOC's etc are user configurable)
  • 433mhz(keeloq) remote key fob control for security lighting or whatever grabs my fancy (currently only controlling lighting but can be easily expanded to turn on equipment as I need) - this is specific to remote control fob user, per button or combination of remote buttons pressed....
  • Timer controlled "smart charger" - if load shedding is scheduled, and SOC is a bit low to carry through due to inclement weather, there is a "smart charger mode" that can be timer enabled to charge the batteries prior to the shed happening - Modes etc are similar to the auto start gennie enviro, but take advantage of the lower cost of mains charging rather than diesel charging if possible (automatically going back to preset running inverter defaults once the event is past)...

Along with probably a hell of a lot more that doesn't spring to mind at the moment!

@lupasha -

All of this is ostensibly wifi based, running on either Tasmotized Sonoffs or custom written 8266 wifi units... As to Home Assistant, I am clueless - this is all running running on a pi4-4gb with a 16gb mem card that is hooked to my inverter, running Node Red as a controller enviro with all the dangly bits reporting in via MQTT(Mosquitto) - CPU usage on the Pi4 hovers around 20 to 30%, so it is far from stressed... Data collection and trending is done with EmonCMS, only because I started with it a few years back and haven't had a chance to redo the front end under an Influx/Grafana environment...



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On 2021/06/24 at 5:24 PM, EdDee said:

with 4x Pylons in the system, SOC switching can be fine tuned to within .25%

You may be able to do better than that: if you run the pwrsys command, the field "System RC" is the system remaining capacity and the field "System FCC" is the Full Charge Capacity.  The more accurate SOC is ((double)SystemRC * 100 / SystemFCC).  The reported SOC is that number, truncated to the integer.

This applies to the whole stack irrespective of the number of batteries in it.


On 2021/06/24 at 5:24 PM, EdDee said:

to charge the batteries prior to the shed happening

Have you found a good source of load-shedding schedules, ideally via an API rather than scraping?  I am aware of https://loadshedding.eskom.co.za/LoadShedding/GetStatus but am looking for actual schedules.


Nice system BTW.  And there I thought that I was a control freak... 😆


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Yeh, seen and used pwrsys type command.... was just using the other status command and just stuck to it... Don't need to go less than .25% anyways, in fact .5 or even 1% is actually good enough for 4 packs... When/if I go to 8 packs, I might relook at it, but nothing on plan in the meantime..


5 hours ago, Calvin said:

Have you found a good source of load-shedding schedules, ideally via an API rather than scraping?  I am aware of https://loadshedding.eskom.co.za/LoadShedding/GetStatus but am looking for actual schedules.

Not really... I use the same link that you quote...

6 hours ago, Calvin said:

Nice system BTW.  And there I thought that I was a control freak...

Thanx 4 da comps... But its not really about the control so much as using as much as you can out the inverter.... Pointless doubling up on output (and losses) until you find that 5kw just cant manage....



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