CI-BUS sniffer
The mobile-home industry uses the communication standard CI-BUS. Unfortunately this bus specification isn't publicly available, so non professional makers will need to sniff this bus to learn how to use it. This project is an attempt to do just that.
I own a Hobby caravan from 2021 that uses the CI-BUS standard for communication between different subsystems in the vehicle. From a central display node I can view and control things like the heating system, battery status, lights as well as reading the water level of the tank and temperatures both indoor and outdoor.
Unfortunately this communication bus specification isn't available outside member companies, which makes it hard for makers and startup companies to develop new additions and solutions for the mobile-home sector.
This project is a first step to gain knowledge of this communication bus, to later make it possible to invent some cool additional functionality to the mobile-homes.
The first step would be a communication protocol sniffer to examine the messages on the bus.
As I've understand it there isn't any requirements for the physical layer of this bus, so I assumed that the LIN-bus would have been selected, because it is cheaper than CAN and still common within the vechicle industry, but from what I've been reading on the internet it is also common to use the RS-485 as the physical layer.
This means that some measurements have to be made to determine which physical layer that a specific manufacturer has choosen.
If you have any knowledge of this, feel free to add information in the comments or contact me directly.
Unfortunately this communication bus specification isn't available outside member companies, which makes it hard for makers and startup companies to develop new additions and solutions for the mobile-home sector.
This project is a first step to gain knowledge of this communication bus, to later make it possible to invent some cool additional functionality to the mobile-homes.
The first step would be a communication protocol sniffer to examine the messages on the bus.
As I've understand it there isn't any requirements for the physical layer of this bus, so I assumed that the LIN-bus would have been selected, because it is cheaper than CAN and still common within the vechicle industry, but from what I've been reading on the internet it is also common to use the RS-485 as the physical layer.
This means that some measurements have to be made to determine which physical layer that a specific manufacturer has choosen.
If you have any knowledge of this, feel free to add information in the comments or contact me directly.
Discussie (2 opmerking(en))
Uncle_Victor 1 jaar geleden
I own an "old" motorhome from Rimor, equipped with a databus control network from ArSilici. Aging 25 years, from time to time units start to fail, ranging from age or corrosion due to leakage. Just like the CI-BUS the protocol is a close guarded secret. (I think ArSilici calls it R-BUS)
Years ago I did some sniffing: physical layer is RS485; baudrate is 9600B, protocol is CAN like. Looking at the used PIC processors in the original units (the main controller is a PIC14000, and the node controllers are PIC16C622), none of them having on-chip CAN hardware, and there is no external CAN controller, the CAN protocol is probably simplified as they have to do it 100% in firmware.
Looking for alternative ways to keep my womo alive, I discovered some years ago an interesting website: womolin.de
It's a complete new motorhome bus control system, but it interfaces with the new TRUMA and DOMETIC stuff controlled by CI-BUS. As it is open-source, you might find there what they discovered so-far about this bus.
Personally I stick for some time to my ArSilici bus, otherwise I have to rewire the whole camper. (a hell of a job)
Being retired for some years now, I always thought I should have plenty of time to finally work this out, including a gateway to the CI-BUS. Reality has proven different...
Today I designed and made a new node controller for my "r-bus". But the pcb has also a LIN transceiver so I can use it on both busses. Having better logic analyzers now then some 10-15 years ago, the time has come to dive deep in the protocol.
For those who have similar "problems & questions" I am open for discussion.
Don't know how Elektor works with e-mail addresses and so, but I can be reached at luc@e2t.be
Homebase is Belgium, mother language dutch, but english, german and french is also OK
Leifson 1 jaar geleden
Unfortunately life happened to contain some unexpected things that made my project stall.
However I hope this will be a bit better from now on...
ADAM Olszewski 1 jaar geleden