Integrating sensors from a car pre ODBII

[eac]

All,
I am considering adding this into my kit car which does not have ODBII but does have analog gauges for all the signals needed to read out.
-Speed
-Tach
-Water Temp
-Oil Temp
-Trans Temp
-Blinker(s)
etc

I am looking for any advice or advisement on the best method to bring the data into the system.
I appreciate any advise anyone has in regards to hardware or wiring.

[Daniel_BlueWave]

From high level point of view.
You need ADC converter to get those value in digital form.

Then you have to write scripts/program that:
- convert those value in appropriate way,
- prepare OBD-II frames and send them to RPI

I would say that this is quite complex task. Try to search in the internet if there is already something like this available.

[GFunkbus76]

I'm working on similar, but life keeps me distracted from much progress. https://youtu.be/zAOZ9d3x4zg ... my engine monitoring has been aided by 'OvensGarage' on youtube - he was working on something similar - his project has also seemed to stall out.

I've since heard of things like "OneGauge" based on arduino(i think) - ThisOldBus on youtube uses it in his RV. There are a few other random options. One other guy here has a VW Kombi/Campervan and used a French board which added canbus to the vehicle for sensors ... I forget the name. He has info on his build thread.

Its generally pretty car specific I think.... So expensive or time consuming. Good luck!

[Ladermeister]

I have the same issue and need to add sensor data that is not available via OBDII to show this data on the "OBD" gauges.
It is not a problem to get the sensor data into the RBPi, but we all need to dig into implementation to get that data into OpenAuto Pro.
It would be great if we could get an option to read data for certain gauges from a text file instead of from OBDII.
In my case I have OBDII but need additional sensor values to be displayed,
user eac doesn't have OBDII and needs all values from external sources.

If we could have text file based gauge option as generic option we all could work out "our" solution without you (Bluewavestudio) having to deal with individual problems.
I think anyone could get sensor data written to a text file using google, so it would be a great and easy solution.


EDIT:
It seems I have found a solution:
https://github.com/Ircama/ELM327-emulator

This is a very sophisticated piece of software, someone clearly did invest moths of work here.
For instance: you can not only emulate and manually apply values to a virtual OBD device, but you can also use a pass-through-mode where you use values from an actual OBD device (USB or Bluetooth) and add custom PIDs on top so that the actual output data stream provides the values from real OBD device (e.g. ELM327) as well as the "faked" values that could come from other sensors.

It is even possible to test by creating one virtual old device and passing that one through another one, so you do not even need to test your "data overlay" with a physical odd device available - which is great for ranch testing on the desktop.
Afterwards we only need to replace the emulated one with the real OBD device, e.g. via BT or USB connection.
It is also possible to do live modification on the emulated values, to do a "virtual ignition-off" and so on.

Currently I am still testing, but this piece of software should allow to add additional virtualized PIDs to insert external sensor data to the already available PIDs that are on real OBD2. Of course, even easier, you can use it for cars without any OBD capability.

Let me know if any of you manage to set up something working, I will also post here as soon as I have something working.

[peetereczek]

EDIT:
It seems I have found a solution:
https://github.com/Ircama/ELM327-emulator

This is a very sophisticated piece of software, someone clearly did invest moths of work here.
For instance: you can not only emulate and manually apply values to a virtual OBD device, but you can also use a pass-through-mode where you use values from an actual OBD device (USB or Bluetooth) and add custom PIDs on top so that the actual output data stream provides the values from real OBD device (e.g. ELM327) as well as the "faked" values that could come from other sensors.

It is even possible to test by creating one virtual old device and passing that one through another one, so you do not even need to test your "data overlay" with a physical odd device available - which is great for ranch testing on the desktop.
Afterwards we only need to replace the emulated one with the real OBD device, e.g. via BT or USB connection.
It is also possible to do live modification on the emulated values, to do a "virtual ignition-off" and so on.

Currently I am still testing, but this piece of software should allow to add additional virtualized PIDs to insert external sensor data to the already available PIDs that are on real OBD2. Of course, even easier, you can use it for cars without any OBD capability.

Let me know if any of you manage to set up something working, I will also post here as soon as I have something working.

Looks very interesting, I need to take a look also in my car

[Ladermeister]

EDIT:
It seems I have found a solution:
https://github.com/Ircama/ELM327-emulator

This is a very sophisticated piece of software, someone clearly did invest moths of work here.
For instance: you can not only emulate and manually apply values to a virtual OBD device, but you can also use a pass-through-mode where you use values from an actual OBD device (USB or Bluetooth) and add custom PIDs on top so that the actual output data stream provides the values from real OBD device (e.g. ELM327) as well as the "faked" values that could come from other sensors.

It is even possible to test by creating one virtual old device and passing that one through another one, so you do not even need to test your "data overlay" with a physical odd device available - which is great for ranch testing on the desktop.
Afterwards we only need to replace the emulated one with the real OBD device, e.g. via BT or USB connection.
It is also possible to do live modification on the emulated values, to do a "virtual ignition-off" and so on.

Currently I am still testing, but this piece of software should allow to add additional virtualized PIDs to insert external sensor data to the already available PIDs that are on real OBD2. Of course, even easier, you can use it for cars without any OBD capability.

Let me know if any of you manage to set up something working, I will also post here as soon as I have something working.

Looks very interesting, I need to take a look also in my car

I came to the end of my capabilities regarding software now - maybe you can help as you write that you are an IT guy?
So far I have managed to wrap together the following:

I have created a shell script that opens a named pipe that allows automated input to EML327-Emulator software. It modifies the hex values of certain OBD PIDs to modify their sensor values.
The shellscript builds a bridge to a MQTT broker and subscribes to different sensor value topics, to which a microcontroller (ESP8266) publishes sensor values via Wifi.
The C-Code on the microcontroller modifies the sensor values from connected sensors to be within allowed range for the different PIDs and I got a decent update rate.
So, basically it works - I created a Sensor-Microcontroller-Wifi-MQTT-OBD-OAP-Bridge.
But now I found out that the ELM327-emulator seems to quit after some hours - and as I am NOT an IT guy I am a little bit lost how I could find out what is going wrong in that software.

(It would be SO good by the way to somehow access the data stream to the gauges somewhere inside OAP…)

So maybe we could collaborate starting from what I got so far?

[BlueWave]

Soon we will release OpenAuto Pro with the API that covers injecting value of OBD-II formulas defined in config. That will allow users to implement gathering and displaying data from any source (without establishing OBD-II connection).

The API will also allow querying OpenAuto Pro for current value of the gauges defined in config.

[odhiambo]

Happy New Year - 2023.

Was this ever released?

[Daniel_BlueWave]

API is available with the latest version of the software.