Digital RPM and Coolant Temp Display

Had quite a few teething troubles but it's finally fitted and all seems to be working.



Went out for a good drive to get everything up to temperature. The coolant temp seems to sit at around 81 degrees when driving.

Neat job, Kiteman,   impressive.......I think you may be getting a lot of orders.  

Kiteman
That's a really neat addition to the dashboard, you continue to excel.

Do you have pictures of the installation of the working parts and the necessary connections?
Can this be reduced to something we could all fit? Say a display, wired to a box, with wires (how many?) to connect to existing van bits?

Also, when we stop after a long run the electric fan kicks in for quite some time (may even continue as we leave the 'van after parking up). What temperatures can you see during such a time?

osg

Nice job kiteman. Where did the controllers and screen come from. I've a nice Bluetooth OBDII transmitter that needs a receiver (the app I was using turned out to be rubbish and I don't have a 'droid phone)

The parts used were

Arduino Uno Microcontroller. This runs the code and talks to the OBDII interface controller, it also sends the information to the LCD display. The code needs to be programmed yourself. I have all the working code and can send that out if needed

OBDII UART board. This talks to the ECU and sends the requested information to the Arduino microcontroller. This is already programmed and just needs to be wired up

Serial LCD. This displays the information.

LCD cable. To Connect the LCD to the Arduino

OBDII to DB9  cable. This is the lead that connects the UART to the ECU port. It IS NOT the same as a ODBII to Serial that is used for a laptop.

The diagram below shows how they are wired together



Once the controllers are wired together the only external connections are to the ECU port and to the LCD. The OBD cable is 1.5m. Plenty long enough. You could probably get a lead long enough for the LCD as well.
If you don't want to cut the dash like I have you will need a housing for the LCD which you could then stick anywhere you want.

The only issue with it at the moment is the OBDII UART is permanently powered from the OBD port. The power running it is minimal but not sure how much it will drain the battery if left for long periods.

If people want a kit I could look into it. Or if someone wants to take the project on themselves I'm more than willing to help as much as I can.

Sunny wrote:

Nice job kiteman. Where did the controllers and screen come from. I've a nice Bluetooth OBDII transmitter that needs a receiver (the app I was using turned out to be rubbish and I don't have a 'droid phone)

You could always buy a cheap 2nd hand android phone and use that. You won't need a sim card or anything. You could use it as a satnav as well

Kiteman said
.

Quote :

The only issue with it at the moment is the OBDII UART is permanently powered from the OBD port. The power running it is minimal but not sure how much it will drain the battery if left for long periods

Presumably the ODB port 'live pin' could be ignored and the OBDII UART wired to the ignition on circuit. If it was to be only one wire to a fuse that is live with ignition on and connecting the cable to the OBD port I would be a customer for a made up version.
osg

Not having any kind of temp gauge does leave a little spot if worry on longer journeys so I might be interested in a made up version too.

I'd also be interested in the code and the complete list of engine info available to see what else might be useful.

kiteman wrote:

The only issue with it at the moment is the OBDII UART is permanently powered from the OBD port. The power running it is minimal but not sure how much it will drain the battery if left for long periods.

That's what I like about my OBD2 Bluetooth sender; it's switches itself into standby if not used.

Quote :

You could always buy a cheap 2nd hand android phone and use that. You won't need a sim card or anything. You could use it as a satnav as well

Had thought of that but would rather make something a bit neater. I'm still thinking of options

osg wrote:

Kiteman said
.

Quote :

 The only issue with it at the moment is the OBDII UART is permanently powered from the OBD port. The power running it is minimal but not sure how much it will drain the battery if left for long periods    

Presumably the ODB port 'live pin' could be ignored and the OBDII UART wired to the ignition on circuit. If it was to be only one wire to a fuse that is live with ignition on and connecting the cable to the OBD port I would be a customer for a made up version.
osg

The power comes from the OBD cable. You will have to remove the pins from the OBD cable plugs. It can be done just a bit of hassle. There's no designated power pin on the UART, you will have to solder the power lead direct to the board where the power comes in from the OBD cable

Tallulah wrote:

I'd also be interested in the code and the complete list of engine info available to see what else might be useful.

Had a quick look at what can be read from our ecu. From what I can make out

Fuel system status
Calculated engine load
Coolant temp
Short term fuel trim -bank 1
Long term fuel trim -bank 2
Intake manifold absolute pressure
RPM
Vehicle speed
Timing advance
Intake air temp
Throttle position
Oxygen sensor present
Oxygen sensor 1
Oxygen sensor 2

Didn't interrogate the ecu any further than that. 

If you do a search for OBD PID the wiki page gives you an entire list of what can be read, it's whether the ecu on ours gives that info

Looks like the OBD-UART didn't like being power continuously and no longer works
New one turned up this morning so did what I should have done at the beginning and removed the power feed from the OBD cable and wired it to the ignition live.
It was a lot easier than I thought. There was a designated 12v pin on the board (I thought it was 5v originally). So took the power from the arduino and all seems to be OK. Will check again tomorrow and ee if it still works.

Looking at the design now it can quite easily be made as a plug and play kit. The electronics can be housed in a box, with an opening for the obd connector and cable coming out that can plug directly to the back of the lcd. To power it all up all you will need to do is wire a plug to your 12v supply and plug that in to the socket on the arduno board.

Is this something people would like? The only trouble is the cost. Parts and p+p are about £110 

It sounds fantastic, but I'm guessing it ain't gonna happen for me, I find my 'wireless' set difficult to tune  

Kiteman said

Quote :

Looks like the OBD-UART didn't like being power continuously and no longer works
New one turned up this morning so did what I should have done at the beginning and removed the power feed from the OBD cable and wired it to the ignition live.
It was a lot easier than I thought. There was a designated 12v pin on the board (I thought it was 5v originally). So took the power from the arduino and all seems to be OK. Will check again tomorrow and ee if it still works.

Looking at the design now it can quite easily be made as a plug and play kit. The electronics can be housed in a box, with an opening for the obd connector and cable coming out that can plug directly to the back of the lcd. To power it all up all you will need to do is wire a plug to your 12v supply and plug that in to the socket on the arduno board.

Is this something people would like? The only trouble is the cost. Parts and p+p are about £110

Would be interested to have the pre-made box despite the price. But have a few questions.
If the OBD-UART didn't like being powered continuously and no longer works - will it fail if turned on during the time of a long roadtrip?
Is the same board vunerable to electrical surges or similar? eg when starting the engine
Can a housing for the LCD be included at that price ? (don't want to spoil the existing dash)
Can it be supplied and used fitted with a plug for the cigarette lighter socket?
Is the OBD connection read only - ie no chance of affecting the running of the vehicle?
If RPM display was changed to be 'Calculated engine load' would this help the driver balance labouring the engine with lightfoot fuel economy?

osg

Will be heading off to Devon in a few days, so I'll see if it lasts

Electrical surges shouldn't be a problem, all power goes through a voltage regulator. My heater panel uses the same stuff and that's still fine

Yes the LCD will be in a housing, so you can put it anywhere

A socket for the cigarette lighter can be fitted, no problem

The UART cannot affect the running of the kombi. The only information it sends to the ECU is to tell it what data it wants

Calculated engine load can be displayed. I haven't looked into this so don't know how valuable the information is when driving

As for cost I will have to search around and see what it will cost to put together. £110 is only a guess.

I'll keep you posted

irishman wrote:

It sounds fantastic, but I'm guessing it ain't gonna happen for me, I find my 'wireless' set difficult to tune  

Scooby is with you on this one . . .

kiteman wrote:

Will be heading off to Devon in a few days

Think the weather is going to be better this weekend   
Have a good one
Roo b Roo

You know that feeling you get when you wish you never started something.

The saga continues  

The system is still working but for some strange reason the van now won't start when the ECU lead is plugged in. The engine fires up then dies immediately. As soon as I unplug the lead she starts no problem, I plug the lead back in she stays running and everything is displayed as it should

Running out of ideas now.

Maybe some kind of feedback loop that checks if there is something connected, and if so that it is drawing power in order to function correctly.

Ie, it assumes that no power means it's not working and therefore everything should be turned off.

Or....

Maybe the power from the ignition is being picked up on one of the other connectors and confusing it?

Kiteman said

Quote :

The system is still working but for some strange reason the van now won't start when the ECU lead is plugged in. The engine fires up then dies immediately

Just wondering if this change coincides with you taking power from the ignition instead of down the multi-pin cable?

osg

Tallulah wrote:

Or....

Maybe the power from the ignition is being picked up on one of the other connectors and confusing it?

I've physically removed the pins on the UART so it's only power source is the ignition live. Must be some sort of data issue but I'm not sure what. The system is still initializing so no data is being transferred. Like you said the ECU must be seeing something but not getting a response. Why I don't know, plus it wasn't doing it the other day

osg wrote:

Kiteman said

Quote :

The system is still working but for some strange reason the van now won't start when the ECU lead is plugged in. The engine fires up then dies immediately

Just wondering if this change coincides with you taking power from the ignition instead of down the multi-pin cable?

osg

Had that problem to start with but changed the code to allow the UART to initialize before running the arduino code runs

Maybe the system needs a shirt delay between starting the engine and requesting any data. The ecu is probably busy at engine start and may get confused if data requests arrive at the same time.

Hi Steve if anything happens to your ecu map Austin at Longlife has a copy of my original map before it was remapped. Tim