At 11:03 AM 3/24/98, you wrote:
>I am attempting to do the following project.  If anyone has done a
>similar project or part, thereof, I would appreciate any advice or
>suggestions you may have.
>
>Specs
>-----
>1.  Sense presence of card using some sensor.  Tell 16c84.
>
>2.  Suck card into slot using stepper motor controlled via 16c84.
>
>3.  Read Magnetic card strip.  All 3 tracks. (not sure whether to
>    do in ttl or rs232).

I don't know anything about the format in which the data is stored on the
strip, but I would immagine that it is independent of the rate at which the
card is swiped past the magnetic head. I would think this because, if this
were not the case and the card had to go past at a specific rate, then we
couldn't have manually swiped card readers, and we do have them. The point
is this: you may not need to use a stepper motor if the rate is not
critical. You could simply use a geared-down DC  motor. Also, unless the
data comes off the card in something similar to RS232 format, I don't see
any reason to try to convert it to RS232, I would just send the
amplified/clipped pulses to the PIC. There is certainly no reason not to
use TTL levels, since these are the only thing that a PIC can accept
directly (without some conversion circuit).

Good luck,

Sean

+--------------------------------+
| Sean Breheny                   |
| Amateur Radio Callsign: KA3YXM |
| Electrical Engineering Student |
+--------------------------------+
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