ncg223 WROTE:hi, thanks for the info.
but i'm referring on the schematic diagram on the 1st page DB-9 connector.
viewtopic.php?f=21&t=11891 here is the link to the schematic diagram(1st page)
is the connection for male and female DB-9 connector is on the same pin??
Well, I cannot be sure now because the discussion is back in 2012 and the hardware is not here anymore. My advise would be:
1. Check the GSM modem with computer to verify the response at DB9/RS232 as shown in the User's Manual. Simple response of AT or OK should be fine.
2. Insert SIM card and try to send SMS to your phone from computer, again this is shown in the User's Manual.
3. Preform a simple loop back test on the URS232A. Short pin 2 and pin 3 on DB9 using female jumper wire. Simply connect the 5V and GND, and RX of URS232A to your controller TX pin; and TX of URS232A to your controller RX pin. Data being sent out from controller will be ping back (loop back) to controller.