Plan to use in car. CAN-BUS

[kebibg]

Hi,
After adding an offline mode will be good
to have CAN-BUS (TWAI) support. Then we can
use it in a car. Can make an additional dashboard.
Or use it in industrial components.

Regards

[fvanroie]

I don't have any knowledge or experience with CAN-BUS networks. To my understanding the messages are only a few bytes in length.
I'm curious to know how do you envision the communication in what openHASP using Can-Bus?

[fvanroie]

Thank you for clarifying your use-case.

I am mostly interested in the low level implementation of the Canbus to MQTT protocol. Is that firmware available somewhere?
You are only sending values to the GUI to update the gauge. So there is no two-way communication from the UI to to the Car/Truck?

[kebibg]

Hi, fvanroie
Sorry for the late answer. If you want I can give you my code for reading DPF from Opel Corsa D.
ESP 32 has a CAN-BUS controller into it. You need just a driver IC to use it. Have 2 types of messages in this communication.
Short and long. Have 2 types of IDs 11bit and 29bit. Data always is 8 bytes. For long messages data is sent on a potion of 8 bytes.

Regards

[marcojk]

Hi @kebibg,
quite OT here, but can you please report the frame/id/payload to read the DPF on a Corsa? I suppose it's on the 500kbs bus...
Thanks

[kebibg]

Hi @marcojk ,
You need to use mode AA!! This is GM-enhanced diagnostic mode. The PIDs are 0129 and 012A. You need to read 8 bytes.
In the next example, I read from CAN-BUS 500K with filter 5E8(because enhanced diagnostic UUDT answer ID is different from standard 7E8!):
AA - ReadDataByPacketIdentifier
0129 and 012A - PID who need to read

AA0129: 5d 13 05 00 0c 00 00
AA012A: 00 1a 5c 00 03 31 00

You need to send it to address 7E0, length 03. AA0129 or AA012A.

0129 REGENS AFTER DPF EXCHANGE, DPF LOAD STATE, DPF DIFFERENTIAL PRESSURE(KpA), DPF DIFFERENTIAL PRESSURE(VOLT),
A:5D
B:13
C:05
D:00
E:0C
F:00
G:00

A - Soot A200/255 in %
B - DIFFERENTIAL pressure sensor in Voltage B5.5/255
C - DIFFERENTIAL pressure sensor in kPa
D
E - REGENERATIONS AFTER DPF EXCHANGE d(hex)= 12

012A dISTANCE FROM REPLACEMENT, DISTANCE FROM LAST REGENERATION, REGENERATION STATE 00-OFF 255-100%
A:00
B:1A
C:5C
D:00
E:03
F:31
G:00

A+B+C dISTANCE FROM REPLACEMENT
D+E+F DISTANCE FROM LAST REGENERATION
G REGENERATION STATE 00-OFF 255-100%

this is the working code for ESP32 and Oled lcd:

https://drive.google.com/drive/folders/1DZZOMxNTfSzW7udh2gvtrMUesNHjIoNK?usp=sharing

Regards

P.S. This is 1.3CDTI engine from Fiat!!!

If you are interested I can give you a document from GM with all specifications in ENHANCED diagnostic just 330 pages.

[marcojk]

Thanks kebibg, great deal of information.
I used a request like this, which is another service
msg.data[0] = 0x03;
msg.data[1] = 0xaa;
msg.data[2] = 0x03;
msg.data[3] = 0xFA;
Unfortunately this worked with engine Z13DTC (the same FIAT+GM as yours) but gave garbage data with engine A13DTC.
I'll test your code, and check the document if you can provide it ;) thanks a lot!

[matsekberg]

I also have ides to use this great user interface solution in my RV. But I think the solution is to use another ESP32 to communicate with the vehicle since there is hardly a on-to-one mapping of values on the bus and values to display. Also, CANBUS is not really in the same scope as a generic user interface component. I would recommend a Arduino software on the ESP32 or try to use EspHome as a interface to the vehicle and communicate with openHASP over a serial port.

[kebibg]

Hi, My code is for Z13DTJ. Regards

…

On Thu, Mar 7, 2024, 12:36 marcojk ***@***.***> wrote: Thanks kebibg, great deal of information. I used a request like this, which is another service msg.data[0] = 0x03; msg.data[1] = 0xaa; msg.data[2] = 0x03; msg.data[3] = 0xFA; Unfortunately this worked with engine Z13DTC (the same FIAT+GM as yours) but gave garbage data with engine A13DTC. I'll test your code, and check the document if you can provide it ;) thanks a lot! — Reply to this email directly, view it on GitHub <#442 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ALDO2NHDBHJI2W4WOJKWSSTYXA7MPAVCNFSM6AAAAAAVP72MR6VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM4DOMBVGQZDQ> . You are receiving this because you were mentioned.Message ID: ***@***.***>