How to read the Vaillant eBus

[dty]

I monitor a lot more than flow and return - like is the flame on, is the pump on, what’s the current output power, what’s the target flow temperature, what’s the current state (S code), etc.

I agree with your perspective Mike. Bear in mind ebusd can and does send messages. Initially, just to try and proactively identify other bus participants. But even if you were controlling it, you shouldn’t be able to make it do anything dangerous! Internal safeties should kick in.

[bruce_miranda]

You can also use ebusd in Read Only mode if you are really worried. Also if you only want to read stuff you can build an extremely easy Arduino shield. I used that for a while before building a proper two way. Now that I have a two way interface, I can switch the max flow based on Evohome HW or CH cycles.

[OpenMike]

OK thanks. I'm going to start simple with an Arduino and a couple of temperature sensors on the boiler pipes. There is an Excel plugin called PLX DAQ which writes the live data to a spreadsheet.

If that doesn't work properly I will look into ebusd. My boiler has a pop-off plastic cover on the front panel and behind it is a connector with a row of five sockets. I've no idea what it does but if it provides access for diagnostic purposes it might include the eBus connections?

Mike

[bruce_miranda]

http://ebus-wiki.org/lib/exe/fetch.p...rduinoebus.pdf

Try this out too. It works fine. I had this built as I was dipping my toe in ebus a few years ago.

[OpenMike]

http://ebus-wiki.org/lib/exe/fetch.p...rduinoebus.pdf

Try this out too. It works fine. I had this built as I was dipping my toe in ebus a few years ago.

Yes I found that circuit during my searches. Thanks for confirming that it works. I will certainly try it if my "external" measurement system fails to satisfy my requirement.

I have my FTDI module plugged in to the Pro Mini. I presume that takes care of the connections shown on the circuit?

Mike

[bruce_miranda]

you can also use the many Arduinos that include an FTDI on board itself too. instead of using two boards.

[OpenMike]

True, but I already have the boards.

Anyway, thanks for all the advice and have a happy Xmas!

Mike

[OpenMike]

Happy New Year everyone.

My little boiler logging project has been quite successful. The water temperature readings aren't particularly accurate but it's the boiler on/off cycles I'm interested in.

Here are some results with three different combinations of pump speed and anti-cycle time. The first one seems to be microfiring. Do the others look vaguely correct?

Mike

boiler_1.jpg
boiler_2.jpg
boiler_3.jpg

[harrym1byt]

you can also use the many Arduinos that include an FTDI on board itself too. instead of using two boards.

I am very new to all of this, but I should like to just be able to read and log boiler data - flow and return temps, pump, firing and Kw, cylinder temperature, heating or HW. I have now wish to control anything.

I had a new Vaillant ECOfit Pure 418 installed last March, in the past month I have added a VR65, VRC470F, VR21 outdoor sensor and VR10 cylinder sensor. All is working absolutely fine, but now I just want to be able to log things - preferably on my Win10 laptop. I have a RPi dedicated to recording my weather station data.

In the 1980's I was well into microprocessors and programming, but most of the modern stuff has since passed me by, so I am starting from scratch and completely lost. I have the house wired for LAN and a couple of wifi AP's.

I hope I guessed correctly, because I ordered an Arduino Nano with built in FTDI and I think I can probably enter that software into it when it arrives, but beyond that - what next?

I have downloaded a copy of Vaillant's Vrdialog on my PC, will that maybe work directly with the USB of the Nano? Assuming I must use a RPi to translate the Arduino's output, could the RPi (V 3 B+) cope with simultaneous weather logging and boiler? If not, what is the minimum spec of RPi which would be suitable.

Sorry for all the numpty questions, but it is a rather steep initial curve.

[OpenMike]

Hi, don't worry about numpty questions, I have a similar background to you and a similar learning curve!

First off, the easiest solution to meet your requirement would be to buy the Vaillant diagnostic kit. It's hard to find these days, but if you're in the UK then you could try these people as they claim to have it in stock:

http://www.plumbdepot.co.uk/product/...ostic-software

For my own system, which simply logs temperature sensors attached to the flow and return pipes, I use an Arduino Pro Mini with separate FTDI module for programming. I detach the FTDI while it's running to reduce currect consumption.

I haven't tried it, but some people have had success reading the Vaillant's eBus with just an Arduino using this circuit:

https://github.com/dpavlin/Arduino-p...r/arduino_ebus