Ah, so this isn't for a specific car then? Perhaps you should provide more details about just what you are trying to do. Just reading an automotive voltage shouldn't require anything more than a voltmeter, so presumably that's not the end of the story. . .?

If you want to read up on OBD2, then http://www.obd2crazy.com/ is a good place to start and find out what it can do and what is available.


Torben

 

Thanks Torben,

No this is not for a specific car per/se. Although I would use it for my car, I wouldn't like it to be for my car only. What if I change cars? What if I have an old car and a new car (which I do)? Then I wouldn't be able to use something that only functions with an ODBC port.

In short, I think it would be best to view this from the perspective of an automotive shop application. I would want to test just about every electrical component of a car (AC and DC) with, I would imagine, a pretty high range of voltage. What would you think, up to about 100 volts?

Can this be done? Is this possible? Am I asking too much?

 

Well, for something you could just plug into a car and read out the values, I think ODB2 is about as close as you're going to get without getting into vehicle-specific interfaces. Google Nissan Skyline for an example of a ridiculously tunable vehicle interface.

Without you having to run wires all over your car to all the different bits you want to test, then back to a central connector (essentially building in your own pseudo-ODB2 system), I'd say your best bet might be just to get your hands on a decent automotive voltmeter. Googling "fluke automotive meters" or such might lead you to some ideas. However, I suspect that those things might be slightly more than you wanted to pay, but as far as I know most folks who've shelled out for a Fluke meter have been happy customers for years after. You won't get an oscilloscope-type readout (but you can get handheld scopes too, if you want) but you'll be able to read any voltage or amperage in your car if you can reach it.

Is that something like what you had in mind? Otherwise I'm not sure what to suggest.


Torben

 

my answer comes a bit late but... come on Torben i don't find your response quite reasonable.. what system you got there? few people play with something less than 1GHz and with 98/95/3.11 nowdays are you one of them?


what do you mean it's not freeware? it's FREE for U!

input frequecy?! what do you expect from your sound card?
it's not a TEKTRONIX oscilloscope.. please check the site again..

 

Just a quick warning for those who wants to play with PC oscilloscopes.... of course It's nowhere as good as TEKTRONIX oscilloscopes but also very easy to damage once you supply the wrong thing

I once found a DOS program which provides a parallel port oscilloscope via a 5V ADC. I mistakenly supplied 15V to it - surprisingly the ADC was not damaged but the parralel port was! Luckily I did not use the built-in port, I use an ISA card for parallel port so replacing it was easy. When the card was taken out, I noticed several chips were severely burned...

At another time I used a sound-card oscilloscope (input via microphone). I was designing FM transmitter so without thinking about the supported recording frequency of a sound card (max. 44.1kHz), I attempted to see the waveform from the output of the RF oscillator. The computer immediately restarted, and after that I found my sound card to be "deaf" - playback was still ok but recording could not work. Probably the too high frequency from the oscillator had killed the microphone part of the sound card?

I always use proper oscilloscope for experiments. To me, PC oscilloscope only works as proof-of-concept.

 

VA appears to me more carefully programmed and I respect the approach its author took, is all. I happen to have several computers, some of them quite old and still working fine. I see no reason not to put older hardware to use if I have software which is still useful and can use it.

In your own words: please check the site again. From the web page:

Any questions?

Thank you for the insight. No kidding it's not a Tek or HP--we're talking soundcard scopes. I have a soundcard capable of 8 input channels at 96kHz. I like to use that if I can. VA tells me I can. This other one doesn't mention it.

All in all I have no reasons to think this other program is as good--speaking purely within the limitations of the soundcard scope realm, as we are.


Torben

 

For basic audio work the soundcard scope is fine. Nobody is claiming it's a replacement for a real scope. It's quick and dirty and cheap at best. If you don't know what you're doing it can be dangerous to your soundcard or computer. Always use a buffer and even then, be aware you can't measure everything.

What was the voltage on the HF signal you fed the thing?


Torben

 

I was measuring the waveform at the inductor and the multimeter showed at least 9V. Not sure if it was the high frequency, voltage or both that killed the sound card.

In my experience audio coming from most headphone output is seldom above 3V. Not sure how high the sound card can "suffer".

 

I've had a hard time working that out myself. Most sources say not to go over 1V on the input but I can't verify that. I choose to be conservative and try to stay under 1V anyway.


Torben

 

Torben we know each other long time from another forum...
up to now we never had something to debate and i want to keep it that way.

although you don't help much...

if you like the program you use then it's fine with me...i just gave an alternative choice...and i did't mean to present my link better than yours (sorry if i did and i didn't noticed it.) but some of your coments you did i think they are wrong! and you keep on this motive insisting.


the program is not freeware but it's free for you to use it... are you going to use it commercially and you mind that so much?!

you said that your soundcard has 8 channels...
are you sure you want so many channels from a software oscilloscope?
nice function if exists...but not even the real oscilloscopes have 8 usualy i think they are 2 or 4 but that's fine for most of us.

about the 96KHz you reffered to...
i think that's your soundcard's sampling rate! and not the audio frequency it can accept.

again...i'll say i mean no offence to you...but you do make me respond because i think some things you say are kinda wrong.

 

OK, I apologize for my tone earlier.

I like to have the option.

Naw, I just use two for this stuff. Just pointing out that not everybody is limited to what a low-end card can do. It's annoying to have one end of the toolchain be up to the task but not the other end.

Correct. As with 44.1kHz sample rate means ~22kHz audio, it's the same for this: 96kHz sample rate means max. ~44kHz audio. Still not a real scope but also 100% more range.

Again, sorry for my tone earlier.


Torben

 

no prob man! everything is fine!