Temp displayed constantly?

Skipjacks · 12-27-2004, 08:39 PM

I'm going to be installing OBDII reader software soon. Before I did the whole computer thing I had a little computer that displayed the outside air temp.

Now I know the OBDII reads the air temp and sends that info to all the code reader programs for display on screen. But is there a way to extract JUST that temp data so that it displays on my screen all the time? Perhaps on the taskbar or someplace I can see it no matter what other programs are or aren't running?

NiN^_^NiN · 12-27-2004, 09:40 PM

You could hook up a temp sensor or the orignal sensor and hook it to the PC through serial or usb and just make a small program to stay in the taskbar

Skipjacks · 12-27-2004, 11:19 PM

Quote: Originally Posted by NiN^_^NiN

You could hook up a temp sensor or the orignal sensor and hook it to the PC through serial or usb and just make a small program to stay in the taskbar

No actually I couldn't do any of that stuff. Hence me asking if anyone else could make a program for me. haha

Iamthehor · 12-28-2004, 11:21 PM

Your outside temp display is probably not connected in any way to the engine computer(Some newer CAN vehicles may make this statement false, im not up to date on that yet). Intake air temp(IAT) is different than ambient most of the time due to it being in the engine compartment and moving.

Skipjacks · 12-30-2004, 02:00 PM

Quote: Originally Posted by Iamthehor

Your outside temp display is probably not connected in any way to the engine computer(Some newer CAN vehicles may make this statement false, im not up to date on that yet). Intake air temp(IAT) is different than ambient most of the time due to it being in the engine compartment and moving.

Oh, well that's a kick in the teeth to my idea.

There's still got to be a way to extract that ambiant air temp data from the sensor to the computer. There HAS to be.

Paradigm_Guy · 12-30-2004, 02:10 PM

Although the car has a temp sensor, I don't think it's an OBD2 sensor, so I don't think that an OBD2 port reader would be able to display this. Anyone know for certain that an OBD2 port scanner can display ambient temp?

Skipjacks · 12-30-2004, 02:19 PM

Quote: Originally Posted by Paradigm_Guy

Although the car has a temp sensor, I don't think it's an OBD2 sensor, so I don't think that an OBD2 port reader would be able to display this. Anyone know for certain that an OBD2 port scanner can display ambient temp?

It depends on where exactly that sensor is too. Our both our cars the intake is right behind the drivers side headlight next to the grill. If thta sensor is in the airbox then the read it gets should be close to ambiant. If the sensor is closer to the manifold, it'll be much much hotter.

Iamthehor · 12-30-2004, 02:19 PM

You'd be better of taking the temp sensors signal and processing it via the serial port or replacing it with one of your own. theres a thread in HW development that has a link to a schematic and software.......
Time to learn some VB

Skipjacks · 12-30-2004, 02:23 PM

Quote: Originally Posted by Iamthehor

You'd be better of taking the temp sensors signal and processing it via the serial port or replacing it with one of your own. theres a thread in HW development that has a link to a schematic and software.......
Time to learn some VB

I don't even know what VB is, let alone being ready to do it! haha

Paradigm_Guy · 12-30-2004, 02:25 PM

Quote: Originally Posted by Skipjacks

It depends on where exactly that sensor is too. Our both our cars the intake is right behind the drivers side headlight next to the grill. If thta sensor is in the airbox then the read it gets should be close to ambiant. If the sensor is closer to the manifold, it'll be much much hotter.

Our sensor is in the driver's side brake duct, it's a yellow and grey probe.

Paradigm_Guy · 12-30-2004, 02:26 PM

Quote: Originally Posted by Skipjacks

I don't even know what VB is, let alone being ready to do it! haha

VB=Visual Basic=Programming Language

Iamthehor · 12-30-2004, 02:27 PM

Quote: Originally Posted by Skipjacks

It depends on where exactly that sensor is too. Our both our cars the intake is right behind the drivers side headlight next to the grill. If thta sensor is in the airbox then the read it gets should be close to ambiant. If the sensor is closer to the manifold, it'll be much much hotter.

It's usually about halfway between the air filter and the throttle body, after the MAF sensor. The biggest problems using that sensor is that it will fluctuate with RPM, uses moving (possibility pre-heated) air, and you have no way of telling how accurate it is vs the *C or *f scale. The car doesnt care if the air is 20* or 50* it just reactes the the voltage and compares it downstream with the O2 data to determine the a/f ratio

Paradigm_Guy · 12-30-2004, 02:29 PM

Quote: Originally Posted by Iamthehor

It's usually about halfway between the air filter and the throttle body, after the MAF sensor. The biggest problems using that sensor is that it will fluctuate with RPM, uses moving (possibility pre-heated) air, and you have no way of telling how accurate it is vs the *C or *f scale. The car doesnt care if the air is 20* or 50* it just reactes the the voltage and compares it downstream with the O2 data to determine the a/f ratio

Our temp sensors have no connection to anything that affects our a/f ratio.

Iamthehor · 12-30-2004, 02:34 PM

Quote: Originally Posted by Paradigm_Guy

Our temp sensors have no connection to anything that affects our a/f ratio.

I'm talking about the IAT sensor that he would be reading through his OBD2 interface

The sensor that you are referring to would be much better as it is calibrated for reading ambiant temp and already has the support electronics built in. If the display was a only for outside temp and the electronics are with the display, I'd bet that the data being sent is a standard protocol and might just act nicely with a serial port but i have no way to test that theory and my experience with german engineering is that they like to reinvent the wheel in many cases.

Skipjacks, if you are interested in learning a little programming, VB is pretty easy to pick up the little stuff on.

Skipjacks · 12-30-2004, 02:37 PM

Quote: Originally Posted by Iamthehor

my experience with german engineering is that they like to reinvent the wheel in many cases.

I see you're familiar with BMW's then...hahaha

Honestly I just bought clips to hold trim peices on the car today and they are the 4th different design I've seen for little plastic clips for the same car! Wouldn't suprise me if the whole car is programed with BMW's own custom OS.

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