Hi! It’s soon winter again on the northern hemisphere and I’ve been wondering if there’s interest in the AutoPi community for monitoring and controlling Webasto heaters with the AutoPi. I know there are commercial solutions available for remote operations of the Webasto but I already have a simple Arduino Mega 2560 with a LCD display monitoring the Webasto Thermo Top V unit in my car.
The Webasto W-Bus is based on the K-line signal levels so it’s quite easy to interface. I located the six pin Webasto Telestart cable under the dashboard and connected the Arduino to it with the L9637 chip. If your car doesn’t have a connector for the Telestart unit you can also connect to the bus from the four pin Webasto clock connector - and of course one can even connect to the bus directly on the heater connector.
Here’s a video by is0-mick 2015 / mickr1969 where I found the necessary Arduino source code and instructions for the Arduino Mega.
My primary goal would be to use the USB ports available on the AutoPi to interface with the Webasto with the libwbus library and a FTDI serial chip. The libwbus is available from Sourceforge and I already have a 15 € USB cable with the FTDI and L9637 chips that works on a PC with the Webasto software. I also have a direct serial cable with the L9637 chip but as far as I know there are no available serial ports on the AutoPi.
If using the libwbus would fail for some reason on the Raspberry Pi/AutoPI my second option is to interface the AutoPI to my current Arduino Mega board via the I2C bus.
The main delay in this project has been that it’s taken me time to choose between the ESP32 based Freematics One+ and the AutoPi but I think I’m now leaning to choosing the AutoPi. The Freematics community forums are currently full of spam and seem to be mostly inactive. Also there’s even less available external connections (practically none if you install the GPS module) on the Freematics One+ than on the AutoPi. The Arduino Due based Macchina M2 was also one of my options but they’re now developing a PocketBeagle based M2 with no known date for delivery. AutoPi seems to be most ready to market with a vibrant developer community. I hope I’m making the right decision, 275 €… (yes, I want the GPS and GSM)
Status update: I was unable to get the Arduino Mega to work reliably enough for daily use. Lot’s of timeouts and connection problems. So I’ll now forget the Arduino / ESP32 / Freematics / Macchina M2 as an option. Also the 2nd Gen AutoPi dongle looks very good and I’ve been able to fork and compile the original libwbus to an old RPi2.
Did you ever come to a conclusion. I am also thinking about getting a AutoPi for my VW T5 with a Webasto Heater. But only if I would be able to control the heater remotely (otherwise I would get another solution that is made for remotely starting the heater).
Sorry, I haven’t had time to compile the libwbus on the AutoPi 2nd Gen dongle. Now that the AutoPi 3rd Gen dongle is based on RPi3 I’ll test the libwbus on RPi3. It should work. I have plenty of RPi hardware from other projects so I haven’t yet ordered the AutoPi dongle. The main reason I would switch to AutoPi hardware would be lower power consumption (RPi and a separate GSM modem consumes quite much…)
Would you have time to write code for RPi/AutoPi?
Very simple start/stop control from AutoPi to Webasto cad be done via simple relay contact. But I prefer data bus based so I can also get temperature data etc. from Webasto so I can see the heater is operating.
To be honest, I am willing to code, but my abilities are quite limited. I also find it very appealing to get proper data bus connections to have feedback and data (probably more that I now get from the in car control unit).
That’s also a reason why I am looking at alternative solutions because the other one would also “just” be connected to the in-car control unit and basically mimic a “start” button press without any feedback. Of course, AutoPi is interesting because besides offering that possibility with the low power consumption, it of course has many other possibilities. But as there is not that much info yet, and non that I can find concerning my car.
And as I said, my abilities are very limited. Therefore I was hoping to find some knowledge to grasp on Nevertheless I would probably also be “happy” with the relay version - but there I am also afraid to brake something…
thanks for the fast reply btw.
Cheers
The special Case in my car is, I actually have two heaters. One is an air heater (for camping) and the other one is the more conventional type warming the water. But the second one is “only” there to aid the enigne to heat up under 5 c° (when it is already running) because these Dieseln engine is so efficient it is not warming up enough to also provide heat to the car interior. But it is supposed to easily be usable to preheat the motor, which is what I would love to do. So I would like to control both heaters (both are from Webasto)
I also have a Volkswagen with a factory installed Webasto. As far as I know conversion from auxiliary heater to a parking heater to pre-heat the engine may require also some new parts. In my car the conversion had been done by the previous owner so I’m not sure how much work it needed and what it cost. Here’s one article I found about Touran/Sharan from Webasto site. I think for T5 the conversion could be similar.
There seems to be also third party solutions available from Danhag which include GSM control.
If you can get the aux to parking conversion done somehow I think it’s not a problem to control two Webasto units with libwbus as I guess the units are completely separate from each other. One would just need two USB to K-Line adapters and two free USB ports, one for each Webasto / W-Bus. Have you located the W-Bus connector/connectors and do you have access to Webasto Thermo Test Windows software?
Yes I have seen quite some conversion tutorials and there are many Kits available. The Dahang solution comes with the SMS feature - but there is no feedback. There are cheaper solutions doing the same thing. Of course, they are not that plug n play. So I would buy a Kit like this: https://wibutec-shop.com/Aufruestsatz-Zuheizer-zur-Standheizung-fuer-VW-T5-mit-manueller-Heizungsregulierung-Climatic-ohne-Bedieneinheit
Without the Webasto Multi Control. That should give me the cable to attach to the heater, which terminates in a connector I should be able to use, if i understand that correctly.
What I found interesting about AutoPi is that I might be able to do way more things with one SIM. Because with the dahang I already need one SIM just for the heater. But I would love to have more functions and still only use one SIM… I would anyway start with the conversion of my already existing Air Top Webasto heater, as the T91 remote is a disaster. If we are hiking and want to start the heating to already have a warm car when we arrive there, the T91 is no solution because I could also start the heater from within the car. I have not yet located the W-Bus connector, but from what I have read, there should be one where the remote receiver is attached. And if the SIM version works, I am willing to ditch the radio remotely in favor of the AutoPi or whatever.
So far I have no access to the Webasto Thermo Test Software. And also no K-Line adapter. Should I buy the 15 Euro cable you mention above? But would the AutoPi not be pluggend into the CAN Bus and therefore block the ability to connect this Cable? Furthermore I think my air heater is not connected to the rest of the Cars so I would need to attach to it somewhere else to… (as mentioned above maybe where the remote is connected, or where the clock is, to program it…)
Thanks a lot for the conversation btw. Really appreciate your help/aswers!!!
Ok, very good! That seems to be a quite reasonably priced conversion kit. Looks like it has also the Webasto four pin connector for the timer.
Yes, the AutoPi connects via the OBD port to the vehicle diagnostic CAN bus. I’ve heard some Webasto units can also be controlled via CAN bus but as far as I know my one does not have that so I haven’t investigated this option further. I really wish it would be that easy to control Webasto from AutoPI via CAN.
So this 15 euro adapter has an OBD connector but the idea is to connect it to the Webasto W-bus with three wires (K-line, Vcc and GND). Usually instructions tell to wire the K-line pin to the Webasto unit special 8-pin connector, pin 2 (diagnostics).
What I found out in my car is that I can also access a W-Bus via the Telestart receiver connector (flat six pin Harwin, 2,54 mm pitch) and timer connector (square four pin Harwin, 2,54 mm pitch). I’m not sure if it’s the same W-bus or not but at least I can get the same diagnostic information from it too and control the heater. Here’s best schematic of the connectors I’ve found so far. For the Webasto special connector this diagram shows a 6-pin connector.
I’m not sure if your units have 6- or 8-pin connectors. If you decide to interface directly to the Webasto units here’s some info about the connectors I’ve found:
Small addition to the previous message, this webshop seems to also have readymade diagnostic cables with 6- and 8-pin connectors and the USB-adapter is only £8.45.
“This is a diagnostic loom for temporary use with the Webasto Thermo Top C fuel burning heaters (FBH) as fitted to Volkswagen, Audi and other VAG group vehicles which use PIN 1 for the diagnostic connection.”
Very interesting. That was my idea to grab the W-Bus signal where the Telestart receiver connector is. I haven’t found it yet, as I currently do not have daily access to my car (it is parked outside my city). But the further I dig in, the more scared I get ;). As I said I am far from experienced with those kinds of things. So probably going for an “of the shelf” version would be a better idea. Especially as there is so little documentation around. It seems that not that many people are actually interested in remotely fiddling with their heater. And then there is the fact that VAG seems to always go a little differently, just because they can… And I don’t want to break anything… I just hoped that with AutoPi that there is a resource I could just basically do it according to. But as the AutoPi 3 really only has one micro USB port and not a single Type A, I would also not know ow to connect those two cables to begin with.
The only thing I am still wondering how I would do the “simple” relay version. So basically mimicking the button press on the internal remote, respectively the conversion kit remote… But I assume I will find resources on that topic (at least I hope)
So you do already have a remote for your heater?
Hi Tillarius! Sorry for the delay answering to you. I’m also bit surprised how few open source Webasto projects exist. I don’t yet have a remote for my heater as I keep my car in a garage for most of the time. But when returning from skiing it would be nice to be able to start the Webasto remotely.
You’re right AutoPi has only one Micro USB port, sorry I did not take that into consideration as regular Raspberry Pi has multiple USB ports. So a low power USB hub would be needed to connect two USB K-line adapters.
