Doug Dotson wrote:

Where does A/D conversion come into the picture?


And the wrong answer buzzer goes off again! I guess I pulled that piece
of jargon out of a dark corner of my mind and used it incorrectly. As
you know, I'm an operator, not a technician. :)

I meant whatever goes on inside the IC that does the conversion. That
IC is what, a bridge or transceiver? I read different terms and
sometimes misuse them not understanding exactly what they mean.

As an aside question, I have a small mouse type GPS receiver, an Altina
GGM-308. It has an in line PS2 (Mini-DIN 6) connector that lets the
receiver be adapted to a number of different power/PDA adapters.

The leads in the connector a

1 - TX (RS232)
2 - +5VDC
3 - TX (TTL)
4 - Ground
5 - RX(TTL)
6 - RX (RS232)

I've been using the serial (NMEA) output and that works fine.

I've also been wondering if the TX(TTL) and RX(TTL) leads are the
outputs for USB ports. Or if some device is needed to handle the
transition between the GPS and a USB port.

I've been reluctant to simply connect 3 and 5 to a USB port data pins to
see what happens.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)