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Having just had a new boiler installed which uses Ebus to communicate round the house, I was interested to be able to read the Ebus messages and check the status of the various parts of the heating system.

So time to press into service a Raspberry Pi using the Ebusd software by John30

Set pi to static IP:

sudo nano /etc/dhcpcd.conf.

Uncomment the static IP section at the bottom (interface eth0 static ip_address=192.168.1.XX/24 etc)

 

A little bit of electronics is needed to interface to the ebus. I made the ebus interface from here:

https://ebus.github.io/adapter/index.en.html

Install ebusd see here

https://github.com/john30/ebusd/wiki/1.-Build-and-install

Configure ebusd to run on boot

https://github.com/john30/ebusd/wiki/2.-Run

make folder /var/ebusd/html (sudo)

Copy static html into ebus html folder just created

sudo cp  -a /home/pi/ebusd/contrib/html/. .

 

Enable rpi uart to be used for ebus (special driver - normally it has a 2 char FIFO)

https://github.com/eBUS/ttyebus

 

sudo nano /etc/default/ebusd

set options - enable auto scan, set device to internal uart, allow for latency, enable http interface

EBUSD_OPTS="--scanconfig -device=/dev/ttyebus  --latency=20000 --httpport=8080  --mqtt port=1883 --mqttjson"

 

 

To see what ebusd is doing

ebusctl state

 

ebusctl info

 

ebusctl find

(shows list of all possible parameters found on the ebus)

 

ebusctl read [name]

shows value for parameter name, as found in the "find" list above

 

To run ebusd on command line, stop service first

sudo service ebusd stop

 

then test uart link for stuff being received:

ebusd -f -c /tmp --logareas bus --loglevel info --lograwdata=bytes -d /dev/ttyebus

 

or trigger full scan:

ebusd --scanconfig=full -d /dev/ttyebus

 

To see http

http://[ipaddr]:8080

To see latest data

http://[ipaddr]:8080/data

 

To see ebus logfile

nano /var/log/ebusd.log

 

install mosquitto broker for mqtt connections (allows dashboardy thing)

sudo apt install -y mosquitto mosquitto-clients

set to auto run

sudo systemctl enable mosquitto.service

It does not seem to update as often as the ebus data does. Not sure why.

 

The VRT350 room controller does not work with the automatic config files for ebusd. But it does work with the 370 config file.

So download all the config files into home/pi/config

Update the ebusd config file to add the command --configpath=/home/pi/config/ebusd-configuration/latest/en

Then edit 15.350.csv to replace everything but the top 2 lines with the lines from 15.370.csv

By changing the r at the beginning to r9 you can make ebusd poll for the latest values (ie ask on the ebus for it). Not sure I want to do this, would be better to request via http.

 

You can request an update using

 ebusctl read DisplayedRoomTemp -f 

 

however this does not always seem to update. You should also be able to do it via http:

http://[ipaddr]:8080/data/350/displayedroomtemp?exact=true&maxage=0

But this seems to send a read command once, then it won't send the read again, for quite a long time (not sure how long)

Eventually I have got round this by implementing TCP in the python script, and sending a read command by tcp with -f option. This forces a read and does work.

 

Graphing

I'd really like to be able to see graphs of how the values change over the day.

To do this I will write a python program which logs all the values to a csv file. Each day will have its own csv. The python will log every 10s but only if the data has changed.

Then we'll have a bit of javascript using canvas.js to render a graph out of the csv file.

 

There seems to be 2 problems here - one is getting the roomtemp to update as described above. The other is keeping the python running, any slight problem and it will crash out. I have put lots of try... blocks in to try to catch all the potential problems.

To run the python from the command line and keep it running use

 setsid python3 disptest.py < /dev/zero >& ebuslog.log &

(edit: this makes an enormous logfile which eventually crashes the pi. better to use the line below:)

 setsid python3 disptest.py < /dev/zero >& /dev/null &

(the & at the end makes it run in the background. The redirects are to prevent kbd input and to log the output to a file).

To check if it's still running use

ps -ef

 

To make it run on boot, put this line in /etc/rc.local

Eventually I have it working, and it is very good

 

The mqtt feed:

 

The graphs:

 

 

From the top: green=flow target temp from thermostat, blue=boiler flow, red=boiler return, cyan=hotwater temp, lt blue=valve state (up=htg, down=hw, centre=off), orange=actual room temp, purple=boiler run (higher line is hw mode)