Hi guys,
I am trying to interface at sensor with a pc. I already know about USB, but was wondering if it is possible to interfacing with a microphone port. If so, does anyone know any good websites that provide infomation on this subject,
thanks
Paul
If the output is in the range between 50Hz and 20kHz, the microphone or line input may work.
If the frequencies are lower, you can use a voltage to frequency converter.
Elektor magazine published some designs using the serial port as a monostable multivibrator to measure resitance and large capacitance.
You may use the joystick port to measure resistance between 1k and 50k.
Wim
"Pauly_G2002" schreef in bericht news: snipped-for-privacy@o13g2000cwo.googlegroups.com...
Maybe you can tell what sensor you're talking about? After al you can connect everything that has wires to the microphone input but it will not make sense most of the times.
petrus bitbyter
googleing PCM2902 from Texas instruments may be interesting, as a starting point
martin
Cheers! Rich
Yes, sorry, how silly of me not giving you the detail, i hwas in a hurry that day
Anyway, I have building a pulse rate device, basically I have a pressure sensor which varries between 0.25V and 4.5V depending on the pressure. Rather than using USB (as im on a budget) I thought about using the line in, firstly as it can be cheaper and secondly I could bypass the A/D convertions,
hope this help makes things clearer on what I trying to do
cheers
Paul
Two obvious problems with that. First that still goes to the A/D converter. Second the input is probably not DC coupled, so that if your signal is slow it won't be seen at all.
-- JosephKK
Well,
Once more I missed at least one message. Seems my ISP cannot handle al the news even while running at least two news servers.
Anyway, I don't understand the "pulse rate" device. A pressure sensor giving
0.25-4.5V over its pressure range makes sense. But that means a relative slowly changing DC signal, which for sure will not be seen by the microphone input. Besides, a microphone tends to act on millivolts. Even the 0.25V will be too high for it.If you want to learn more about PC-port interfacing have a look at:
FAIK this site does not mention the gameport interface. This interface can be used to measure voltages from about 4V upward. Described - amongst others - in some Elektor books.
petrus bitbyter
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