MNORRIS@irlearn.bitnet (Mike Norris) (07/11/89)
Here's the task facing our Physiotherapy School: One the one side, they've got an 8Mhz PC-XT. And on the other, there's a host of sensors, microswitches and other devices (such as an EMG) producing low-voltage analogue signals. They would like to have the PC capture these various outputs (there are six in all) so as to facilitate analysis; at the moment, they use an array of storage display scopes (with cameras) and a chart recorder. It looks like a multi-channel analogue-to-digital converter (ADC) fitted to the PC might do the job. Eight-bit resolution would do, and the device would have to have a sampling frequency of about 10 Khz (for all of six channels). Has anyone gone this route already, or even done something remotely similar? If so, I'd be very glad to hear of it, or of any source of solutions to this task. Many thanks. Mike NORRIS
dd26+@andrew.cmu.edu (Douglas F. DeJulio) (07/12/89)
Believe it or not, the joystick port for an IBM PC contains four A/D converters. Joysticks work by having two trim-potentiometers each, and one joystick port can handle two joysticks. They'll return an 8-bit value depending on the resistance across two of the pins on the port. They're also about $20 bucks a piece. Hope this helps, and check to make sure it's accurate first.
clarke@acheron.uucp (Ed Clarke/10240000) (07/13/89)
From article <4YiopGa00XcQM2IZcu@andrew.cmu.edu>, by dd26+@andrew.cmu.edu (Douglas F. DeJulio): > Believe it or not, the joystick port for an IBM PC contains four A/D > converters. Joysticks work by having two trim-potentiometers each, > and one joystick port can handle two joysticks. They'll return an > 8-bit value depending on the resistance across two of the pins on the > port. They're also about $20 bucks a piece. > > Hope this helps, and check to make sure it's accurate first. Nooooooo! They're not A/D converters but rather 555 type single shots. The game card is useless for anything except joysticks. Try Data Translation - they make a whole series of cards that can do what you want ~$1000 for a twelve bit 16 channel (or 8 differential) analog input card (DT2801). Card also has 2 D/A and 16 bits digital I/O. Easy to program too ... I'm just a customer, no financial interest etc. etc. etc. etc. -- Ed Clarke acheron!clarke
BLUMBERG@BGUVM.BITNET (Dan Blumberg, Dept. Of Geog. Ben Gurion Univ. Israel) (07/26/89)
I do not know anything about using joystick cards for D/A but we faced a simmil
ar problem in our wind tunnel here. We had to recieve wind data from several
instruments, Temperature from a thermocup etc. We turned to the Data translatio
n card and found it to be a very good and efficent solution. easy to programme,
we used assyst for the programme, and very reliable. (This was done with the he
lp and advice of our computer centre).
Danny Blumberg