Reply With QuoteI don't see why not. If you drop me a DM with your email address, I'll add you to a Slack group where a bunch of us who know about these things hang out.
A quick question for those using custom receivers for decoding the Rameses protocol - does anyone know the feasibility of using an RTL-SDR (generic software defined radio) to receive and decode the packets for monitoring purposes, and whether there is any software already written that might be able to do so ?
I have one of these: https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
I currently use it for messing around with - primarily for receiving and decoding the 868.3Mhz signal from my Bresser 5 in 1 weather station outdoor unit - which it does brilliantly with a program called rtl_433 which does the decoding of the signal. I also use it for monitoring ADS-B locator transmissions from planes, (up to 50 miles away just with an antenna stuck to the inside of a window, so it seems reasonably sensitive!) and also use SDR Sharp as a general purpose software radio with it.
I can easily tune in 868Mhz in SDR Sharp and see the little blips from Evohome, my Loop energy monitor and my weather station - all of which are relatively close in frequency to each other but have their own distinctive signature on the spectrogram display.
An RTL-SDR is receive only of course so it can't send any messages to the Evohome devices or send requests to elicit responses, but passive monitoring would still be useful for diagnostic purposes and learning more about the protocol and behaviour of the devices. And if I can do it with hardware I already have and cobbling together some software, that's cool.
So is it possible ?
Last edited by DBMandrake; 22nd May 2019 at 10:45 AM.
I don't see why not. If you drop me a DM with your email address, I'll add you to a Slack group where a bunch of us who know about these things hang out.
Hi,
I'm interested in controlling Honeywell devices as well to have some sort of smart home heating. Recently moved into a house (UK) where it has a Honeywell CM707 as a thermostat (although mine is rebranded) and a BDR91 as the boiler relay.
Although it's really early days for me and I don't have much experience in radio (more have a software background), I picked up an RTL-SDR USB stick to do some sniffing of my thermostat. Managed to pick the signal in Universal Radio Hacker but can't seem to write a decoder for the Evohome protocol. However, I saw this post at another home automation forum which should process Evohome signals -- https://github.com/ernst-s/luaradio-evohome. Haven't tried it myself, but might be worth looking into?Originally Posted by DBMandrake
Thanks, that looks exactly like what I'm looking for!
I'll report back if I get it working.
Following the recent evohome web api outage, I have now updated the evohome-listener python/mqtt script to include sending of basic commands (controller mode, setpoint overrides, dhw state etc) via mqtt. You should be able to easily modify it to send other commands if you need to. Pls note though that I could only get the send to work using @petep's fifo branch. I wasn't able to get any response using the master branch, even with different speeds.
Smar are you also running it on an ESP8266 module? Are you also using Domoticz to read-out the heatdemand for the different zones?
Got it to work, however I had to make changes to one of the lua block files before it would work. See my post on the linked thread. Luaradio and the necessary dependencies are quite some work to compile and install however I figured it out in the end.
I tried it on both a laptop running Linux Mint and a Raspbery Pi 1 - it didn't seem to work very well on the Pi (it runs but rarely decodes a message) so I suspect Luaradio is too CPU intensive for the original Pi 1 for continuous reception but it might work on a Pi 2 or 3.
Last edited by DBMandrake; 31st May 2019 at 10:24 PM.
No, I'm running on an Arduino. Heat demand readout is given directly by the python script, but I do use openHAB (another home automation system, similar idea to Domoticz) to log/graph the data, and also for controlling specific evohome events, such as turning heating off when no one at home for an extended period of time etc. As the data is being published onto MQTT, you should be able to use it with almost any home automation system.
Hi,
I've now published a couple of Python scripts which perform a backup and restore of the schedules to/from a text file using a serial device. This might be useful if you want to perform bulk changes to setpoints for example. During testing I've confirmed that the maximum number of setpoints per zone is 42 which can be distributed across the week however you wish.
https://github.com/Evsdd/Evohome_Schedule_Backup
https://github.com/Evsdd/Evohome_Schedule_Restore
Regards,
Dan
Thanks for this - very useful.
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