Modem configuration

Archiver

Hello! I am trying to connect a USR Sportster 28.8 modem to a STAMP
BS2-IC for a remote data-logging application. I have read the Nuts
and Volts application notes as well as the examples in
the "Programming and Customizing the Basic Stamp Computer" and still
haven't gotten the modem to respond.

I believe the problem is a bank of DIP switches which configure the
modem. I've tried going through most of the combinations without
success. These are my connectsions:

Modem Pin2(TX) -> Stamp Pin2
Modem Pin3(RX) -> Stamp Pin1
Modem Pin7(Gnd) -> Ground
Modem Pin22(RI) -> Stamp Pin0

This is essentially the same setup shown on page 152 of Scott Edwards
book. I have also connected it to my PC and typed the commands (I
didn't notice the RD light flashing, however). The DIP switches are:

DIP1 -> (up) Data Terminal Ready Normal
(down) Data Terminal Ready override
DIP2 -> (up) Verbal result codes
(down) Numeric result codes
DIP3 -> (up) Suppress result codes
(down) Display result codes
DIP4 -> (up) Echo offline commands
(down) No echo, offline commands
DIP5 -> (up) Auto answer on first ring
(down) Auto answer off
DIP6 -> (up) Carrier detect notmal
(down) Carrier detect override
DIP7 -> (up) Load NVRAM defaults
(down) Load factory defaults
DIP8 -> (up) Dumb mode
(down) Smart mode

I prepared the BS2 for communication with DIP7 up (can't the modem be
prepared with comm strictly using the switches?). I was using the
following setting: up,down,up,down,down,up,up,up.

When I dial my number with a cell phone, the "AA" lights up on the
modem but the stamp cannot detect the RI line going to a 1. Can
anyone offer a solution?????

Thanks
--Jeff

Here is the code:
tlink con 15000
N2400 con 16780
TxD con 2
RxD con 1

RI var IN0
name var byte(10)

WaitForRing:
debug bin RI, cr
if RI=0 then WaitForRing

PickUpPhone:
debug "picking up phone",cr
serout TxD, N2400, [noparse][[/noparse]"ATA",cr]
pause tlink
serout TxD, N2400, [noparse][[/noparse]"Please enter your name: ",cr]
serin RxD, N2400, [noparse][[/noparse]str name\10\cr]
serout TxD, N2400, [noparse][[/noparse]"Thanks for calling, ", str name\10, cr]
debug "Thanks for calling ", str name\10, cr
pause 1000
serout TxD, N2400, 100, [noparse][[/noparse]"Hanging up now.",cr]

Disconnect:
pause 2000
serout TxD, N2400, [noparse][[/noparse]"+++"]
pause 2000
serout TxD, N2400, [noparse][[/noparse]"ATH0", cr]

goto WaitForRing