OBD2 Adapter: MFA via OBD2

Hi there,
and it's about the same thing again,
data such as, for example, coolant temperature or charging pressure, etc.
to extract data from the CAN bus or the OBD interface.
After doing a little research,
It might be a bit difficult to retrieve the data from the CAN bus.
If you don't have the original communication protocols (for identifying control units, etc.) from Volkswagen.
It might be easier to do it via OBD.
According to what I've read, the Elektor OBD2 adapter converts the data into ASCII format, allowing it to be read using a program like HyperTerminal.
ASCII data is relatively simple, and everyone knows how to handle it.
Before I buy the adapter from Elektor, I wanted to ask here if anyone might have it and what the included software looks like.
greetings

Okay, so.
Just a little closer.
To be precise, it will actually be very simple.
I found a description of the adapter from Elektor.
The communication of the OBD interface is very simply structured.
As one might expect,
'You send something to the car, and the car responds.'
Simple HEX data is being sent.
The Elektor adapter performs functions such as data verification and adding a checksum, allowing you to easily retrieve the hexadecimal data.
a brief description of how it works.
1. You plug in the adapter, and then the adapter initializes the communication with the OBD interface; you don't need to do anything.
The adapter maintains the connection even when no data is being sent or received.
2. You send a hexadecimal code that addresses the desired control unit.
which then remains in the pipeline and waits for commands.
3. Then, a hexadecimal code is sent, which contains information about what action should be performed.
In our case, that would be sending the coolant temperature.
4. The control unit transmits the coolant temperature in the form of a hexadecimal code.
5. Now, the processor that we programmed needs to convert the hexadecimal code into decimal.
This means that the received hexadecimal data '7b' is converted to decimal, which results in 123. Then, 40 must be subtracted, and you get the cooling water temperature of 83 °C.
To get a continuous display, you need to query more frequently.
So far, so good.
The necessary HEX commands are all described in the SAE J1979 standard.
Okay, here's the problem.
I called and they said you can order the standard in paper format in English.
But that costs 74 euros.
Maybe someone of you can get it for a cheaper price?
or perhaps a cost-sharing arrangement.
This is aimed at those who are also interested in this topic and may have even programmed microprocessors before.
greetings

Why reinvent the wheel when there's VAG-COM...?

The Elektor adapter does not work with VAG-COM.

Here's something I found online about this topic:



Supported SAE J1979 parameters.
EFILive V5 supports most of the SAE-J1979 emissions-related parameters, which are listed in the following table.
PID Description
$00 Supported PIDs ($01..$20).
$01 System readiness tests status.
$02: Trouble code that triggered the storage of freeze frame data.
$03 Oxygen sensor status (Bank 1 and Bank 2).
$04 Calculated load value.
$05 Engine coolant temperature.
$06 Short term fuel trim (Bank 1).
$07 Long term fuel trim (Bank 1).
$08 Short term fuel trim (Bank 2).
$09 Long term fuel trim (Bank 2).
$0A Fuel pressure (This parameter is not supported by GM).
$0B Intake manifold absolute pressure.
$0C Engine RPM.
$0D Vehicle speed.
$0E Ignition timing advance for cylinder #1.
$0F Intake air temperature.
$10 Mass air flow rate.
$11 Throttle position sensor.
$12 Commanded secondary air status.
$13 Location of O2 sensors (Some manufacturers use PID $1D).
$14..$1B Oxygen sensor output voltage and fuel trim for sensors 1 through 8. EFILive V5 uses the GM-specific alternatives for these values.
$1C OBD requirements to which this vehicle is designed.
$1D Location of O2 sensors (Some manufacturers use PID $13).
$1E Auxiliary input status.
$1F: Not used.
$20 Supported PIDs ($21..$40).

@ DirkC4

Hi,
As far as I understand, he doesn't want to read the data using a Windows application, whether it's more or less user-friendly, like 'VAG-COM' for example.
It's probably more about simply extracting individual measurement values.
CAN-Bus, adapter, processor, display.
The example of coolant temperature is interesting because the Lupo 3L does not have a standard display for it.

Best, Andy.

Okay,
VAG COM states that the Lupo 3L is OBDII compatible.

and as the clever Andy already correctly pointed out,
Basically, it's about adding a temperature display to the Lupo 3L because it doesn't have that feature .
greetings

hi,
I now have more information about the Elektor adapter:
You type the command in hexadecimal format in the HyperTerminal.
'But HyperTerminal actually sends out ASCII characters.'
The adapter receives ASCII data, converts it into hexadecimal code, adds a checksum, and then transmits this information to the car.
The car processes the commands and sends data back, for example, in HEX format.
The adapter converts these back into ASCII characters and sends them to the HyperTerminal, where they are then displayed as letters and numbers in 'HEX' code.
So far, so good.
Overall, that means that if we already have a microprocessor, we don't need this adapter from Elektor.
However, if we want to try connecting to the PC first without the adapter, we'll need a program that sends the data in hexadecimal format, similar to HyperTerminal, rather than in ASCII.
greetings

Hello,

Perhaps this information on this link will help you:
http://hex.co.za/vaginfo/

hi,
It goes on.
With the Portman program, you can log the communication of a serial port, and the transmitted and received data can be displayed in ASCII or hexadecimal format.
You can also set filters so that you no longer see unnecessary rows.
I will simply use VAGCOM to log the data and utilize the corresponding commands.
greetings

Hello,

I recently found the following: bittnet.de/scs.html. Someone has created a kind of onboard computer for the Audi 80. As far as I understand it, this is not too far from your project. I hope this was somehow helpful .

Regards,
Michael.

hi,
A nice display.
But the principle is different.
He gathers the data himself by tapping into the sensors, etc.
We will do it through the diagnostic interface.
But the display is really beautiful.
now it's highlighted in blue and it fits .
greetings

Hello everyone,
I found an FAQ that describes how to build an OBD II interface yourself. Maybe this will be helpful to you. I tried it myself with VAG-Com, and it works great. http://www.meckisfaq.de/antworten/schaltplaene/diag/

Andi

Hello Andi,

HeizoelpowerA3 wrote:

Hello everyone, I found an FAQ that describes how to build an OBD II interface yourself. Maybe this will be helpful to you. I tried it myself with VAG-Com, and it works great. http://www.meckisfaq.de/antworten/schaltplaene/diag/ Andi

Then you haven't really looked at these pages yet .

/viewtopic.php?t=3089

Best regards, Rainer.

How do you mean that?

hi,
Okay, the hardware isn't a problem.
not even the software on the microprocessor.
the problem isn't understanding the concept, but figuring out the commands.
But it probably will work with portman.exe.
greetings