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DELETED (Inactive)
3 Posts |
 Posted - Mar 13 2003 : 5:50:25 PM
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Hey,
I want to hook up an oil pressure sender to a computer that I will put in my car. I have minimal electronics experience, but have written programs in C on a Linux platform to light an LED, and let me know when a microswitch is closed.
I know that the oil pressure sender that I am going to use is basically a variable resistor.
Does anybody know how I would convert the reading from a basic Ohmmeter into a digital signal so that the parallel port can read it?
Any advice would be greatly appreciated.
GCON
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Mar 14 2003 : 11:30:29 AM
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Connect up a voltmeter to the lead going to your oil pressure guage.You will most likely find that that lead outputs a voltage dependant on your oil pressure. Simply connect up a simple ADC circuit to read that voltage. If you search the web for "analog to digital converter schematic" you will probably find what you need.
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DELETED (Inactive)
3 Posts |
Posted - Mar 14 2003 : 12:30:59 PM
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I found a few ADC circuits such as the following:
http://www.ecdl.hut.fi/S-87.137/HANNU/ch8b.pdf
http://www-s.ti.com/sc/psheets/slas221/slas221.pdf
I am no electronics wizard, so the first one there is more appealing to me. It looks like something relatively simple that I could throw together (if i could find a chip that does the logic for me). The second one has so many inputs that I have no clue what to make of it. I think that the second one would be much more accurate, however. Tell me if im wrong, but with the first one, a 2 bit converter, I could write a program that would tell me if the oil pressure was between 4 ranges. The second one, an 8 bit converter, could tell me 255 ranges. The second one is much more appealing. The problem is I have NOOO idea how to wire something like that. There are so many reference voltages, power downs, yada yada.
Do you know of a simpler chip/circuit that I could use? If that 8 bit one seems right, could you please offer advice on how to wire it?
As always, all help is greatly appreciated.
GCON
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DELETED (Inactive)
191 Posts |
Posted - Mar 17 2003 : 11:39:09 AM
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Try www.analog.com
They have a lots of device that are prethy simple to conect. they also have a lots of information and example in there data sheets. They also provide sample. so you will probably not need to pay for your component.
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Mar 17 2003 : 3:04:38 PM
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I can't view those circuits since I don't have Acrobat on this PC, but it sounds like they are standard ADC circuits. As far as I know, there is no "single chip" solution. You might consider using the joystick port, which is a VERY simple ADC circuit. Or even the sound card, which has a very good ADC as well.
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DELETED (Inactive)
191 Posts |
Posted - Mar 17 2003 : 4:07:01 PM
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Hey that is a good suggestion. Sound card. I always forget to use it. It's a real low cost solution and quite easy. it could acquire data on two channel at the same time for a rate of 44KHz. We must sugest that to the other people.....
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DELETED (Inactive)
3 Posts |
Posted - Mar 18 2003 : 09:12:42 AM
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The sound card is not really an option, because once i get this all set up it's going to be part of my in car MP3 system. I considered the game port, but couldn't find much useful information on it.
There is a one chip solution, however. There are several chips that support serial I/O. The one I chose (and should recieve in a few days) is national's ADC0838. I chose this chip because of this page:
http://www.phanderson.com/printer/0838/0838.html
It seems to give all of the information that I need.
Now I just need to figure out the best way to test my circuit with a SOIC WIDE chip .
Thanks for all of the help
GCON
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DELETED (Inactive)
191 Posts |
Posted - Mar 18 2003 : 11:17:14 AM
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I'm happy that you find what you are looking for. Good luck and of course have a lots of fun....
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Oil Pressure reading from PC
