Digital RPM and Coolant Temp Display

After reading about Sunny using the OBDII and the App on his phone got me thinking.

My next project is to get a readout of the Coolant Temp and display it similar to my Heater Project. Whilst I'm at it, will display the engine RPM as well.

Well today the bits have turned up.



First thing to do is solder the parts together and Program the microcontrollers.

That looks interesting Kiteman, is that going to be a real time display on the dash.

Something I'd like to have, .....saves buying  a separate rev counter and temp gauge and all the associated fitting and wiring.

dizzylizard wrote:

That looks interesting Kiteman, is that going to be a real time display on the dash.

 Yep. I'm hoping to fit it below my heater touchscreen panel

Looks like I've hit a major problem.

The Micro controllers read the information from a cars CAN-BUS, which our Kombi's don't have,  I thought they used the OBDII protocol .

It works a treat on my car, but that's already got a rev counter and temp gauge.

Looks like it's back to the drawing board.

The project is back on track again  

Found a controller that will read the OBDII data.

Taken me a couple of weeks to get the code working, especially as the supplied code was wrong  but finally have it reading the RPM and Engine Coolant Temp.





Just need to install the display into the dash. Might look into getting average MPG displayed as well

The 'Kitemaster' does it again, bit slow at work then fella  

Top job

Like that. Would like to display instantaneous fuel consumption rather than avg, as I can get overall avg from fill-up stats. Instantaneous gives an indication of how well one is driving / labouring / flogging the engine.

Brilliant as usual Kiteman. You really should market these in kit form.
I think Sunny has a good point that instant readout of current fuel consumption is more useful than an average.
osg

Well done - looking forward to seeing the completed display  

I always forget to check milage and amount of fuel used when I fill up, so never know my MPG.
Plus I never use the instantaneous MPG for my car, always the trip average.

Great job again Kiteman, like others I will be interested in knowing how it all works.

Should be able to get MPG readings as well by the looks of it.

The OBD doesn't send MPG data itself, but after a fair bit of reading online it looks like it can be calculated by using the Mass Air Flow, Vehicle Speed and Long Term Fuel Trim data.

Will have a play over the next few days and see how it comes out.

Hi Kiteman,

What OBD reader did you use? I bought a cheap one from amazon but I cant get it to work (and am presuming you plug it in to the EMU above the battery?)?

This is the one I bought -
http://www.amazon.co.uk/gp/product/B004KL0I9I/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1

Gordonmac - don't forget kiteman runs an AquaBay, not an AirBus.

Doh! Thanks Tim, I presume that airbus doesn't do OBD2 then.

gordonmac wrote:

Doh! Thanks Tim, I presume that airbus doesn't do OBD2 then.

You certainly can get a diagnostic readout from the ECU but I'm not sure if you'll be able to access the rpm etc that way. I've not really looked into making use of running ECU data from my AirBus .... yet! I tend to listen to the engine, it's very good at telling me if something's wrong.  

Back in the 60's, I had a vacuum gauge that tapped into the inlet manifold on my MGTC. Most efficiency was when the needle was in the green sector. (If you accelerated hard, or the engine was labouring it dropped into the amber or red area indicating you were using too much petrol)

If I remember correctly it had other functions as well, like a fluttering needle indicating faulty valves etc.

That one was with a capillary tube, but I should imagine now there is an electronic sender version if the OBD won't read it, having said that I'm sure you will crack it either way Kiteman,  Top-man

Reference the above, found this article showing what can be done with a vacuum gauge, which may be of interest.


http://www.classiccarhub.co.uk/articles/tuning-and-fault-finding-using-a-vacuum-gauge.html

kiteman wrote:

Should be able to get MPG readings as well by the looks of it.

The OBD doesn't send MPG data itself, but after a fair bit of reading online it looks like it can be calculated by using the Mass Air Flow, Vehicle Speed and Long Term Fuel Trim data.

Will have a play over the next few days and see how it comes out.

By the looks of it the Aquabays don't have a Mass Airflow Sensor, or if they do I'm not getting any data from the ECU for it  

Looks like I'll be sticking with the original RPM and Coolant Temp.

Next step is fitting it into the dash

gordonmac wrote:

Hi Kiteman,

What OBD reader did you use?  I bought a cheap one from amazon but I cant get it to work (and am presuming you plug it in to the EMU above the battery?)?

This is the one I bought -
http://www.amazon.co.uk/gp/product/B004KL0I9I/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1

What are you using to read the data from your reader?

It might also be that you are too far away from the reader to pick up a signal. Bluetooth doesn't transmit that far, especially if its tucked away in the corner of the engine bay surrounded by metal.

I'd be surprised if your ECU didn't give out any data

The reader I'm using is OBD-II UART reader

All it does is talk to the ECU, I'm using another controller to read this information and show it on the screen.

Hi Kiteman,
Ive been using a free iPhone app, bluetooth seems to connect but nothing happens in the app. There is one of those tiny CD roms which came with it but I need to locate a computer which can handle that before any attempt at trouble shooting. Perhaps should have spent more than £6 on my reader!

Tim - you will be very jealous if we've all got this working and you don't. You'll have to get on it too!

gordonmac wrote:

Tim - you will be very jealous if we've all got this working and you don't.  You'll have to get on it too!

I'll let you inadvertently remap your ECU by connecting your Kombi to iTunes or something!  

Think your problem might be with your iphone. Apple like to have a tight control over what you can do with their stuff. There are a lot of things you can't use bluetooth for with iPhones. 
Try an Android device if you can, you might have more success.

OK - cheers - that might be the problem. Will try to borrow someones android phone and see if that works.