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Hi,

I’ve got a rather nice home control system set up that I’ve created. It uses a Rpi and wireless temp sensors and an 8 channel relay board. From the system I can monitor multiple “zones” in the house and control my zoned gas heating via a set of motorised valves and pipework. I also have connected a few sets of garden lights and a secondary hot water pump. I have a web interface to monitor and control all this via what is effectively a software version of standard heating programmers with 7 day timer and temperature function per zone.

So, all’s good and it works really nicely, I’m sure its saved a lot of wasted energy as when I’m home late I can snooze the system, turn off zones when I’m away etc…all in all I’m quite proud of it…I’ve included all sorts of email alerts, error handling, configuration.

The problem is…I’ve some friends that want the same and asked me to build them a copy, easy peasy…but I’ve been using temp sensors and receivers from company called wirelessthings, formerly ciseco who are out of business…so I’m looking to change to a new supplier for temp and receivers and stumbled across openenergymonitor…looks good. (a little more expensive)

From my initial reading I think if I plug a RFM69pi into my pi and then get a couple of Emon-Th sensors i’ll be back in business…but I’ve a couple of questions…

  • Can I only have 4 sensors per system? I have 4 zones and a sensor in my hotwater tank dry chamber at the moment so to replace would require 5.
  • Does the battery life extend from 7 months to 21months if I drop the temp send frequency to 3 minutes?
  • Has anyone written any code to receive the temp readings via the serial port and handle them in python and save to a DB. My system is written in 2 parts, a scanner job that reads the serial port and writes the temps to a db…and second control job that loops round, checks the schedules and latest temps to determine which zones to turn on and off…so I’m hoping to simply replace some of the code I have already to read from the serial port and just handle the strings of data differently…that’s my hope anyway.

So, any advice most welcome. Some info on my system is here: www.totalcontrol9000.co.uk (I played doom when I was a student :))

I will investigate the wider open energy range of solutions and look to include this, perhaps I can start to monitor my energy savings that I get from a smart home, but for now I’m keen to get my project back on track with a supply of sensors and receivers. I’d be happy to share my existing sensor message handling code if anyone is interested.

many thanks for any info

Chedz

I had a look at your website (I think you are much better in creating technical appliances than websites :slight_smile:)
The system you have created looks awesome, bit also quite complex to build. I think I have a similar system at home through Honeywell’s Evohome system including a Ninjablock (which is starting to become redundant) and a raspberry pi. Ok, most probably the cost of my system is much higher (around €900 for all switches, heating controls etc)
Find the script I am using to get the Evohome values here: Script for feeding Honeywell Evohome data into Emoncms

Additional node ID’s can be set by chaning the nodeID in the code. Its possible to have up to 30 nodes per RF network:

It would improve significantly. Even better wait for our emonTH V2 (due to be released in the shop in three weeks) if battery life is important. 2yr+ battery life is expected

Has anyone written any code to receive the temp readings via the serial port and handle them in python and save to a DB. My system is written in 2 parts, a scanner job that reads the serial port and writes the temps to a db…and second control job that loops round, checks the schedules and latest temps to determine which zones to turn on and off…so I’m hoping to simply replace some of the code I have already to read from the serial port and just handle the strings of data differently…that’s my hope anyway.

On our pre built SD card image emonhub posts the data received via the RFM69Pi to MQTT (mosquito server running on the emonPi). A nodered flow could easily be setup to save these values to a file. Or you could log the data to Emoncms (locally or remotely) then use the Emoncms API to retrieve the data.



Thanks a lot Glynn, great info.

Hi frank.

The system may look complex but really it’s very simple. Each heating zone has a motorised valve and that has a pair of wires that normally goes out to your wall mounted 7-day programmer in series with a mechanical room stat…all I’ve done is replace this with a relay controlled via a software schedule and use a wireless temperature sensor. This means I can have many zones with individual programs and set the temp to what I like when I like. The complexity comes from having 5 zones each with a valve…with traditional stuff I’d have a big jumble of wires all over the house…if I’d gone with COTS ‘smart stats’ I think have had to spend about £1000 to achieve this and end up with tricky to control system…I can control all zones from a single screen on my iPad or phone.

Cheers

Imagine the voice of Columbo…just one more question…

Wirelessthings had a rather nifty 5 button key fob which when pressed sent a labelled trigger message into the system, I wrote software to allow actions such as ‘turn on zone 3 for 10 mins’. (Porch lights) or boost heating for 1 hour at 21 degrees to be configured for each button.

do you have any plans to do something like this?

I’ve got the backend code working, but didn’t write the front not end config screen yet.

Thanks