Contest Winner (SMS Scheduler using GSM Modem)

By: Michael Fischler

Introduction

This project will simulate the action of a user sending SMS votes to a contest. This process is automated by the controller in order for the user to send more votes at a faster pace. The controller interfaces with a GSM Modem to send each vote and to receive confirmation replies from the contest. The memory in the GSM Modem is dumped in order to keep space open. All activity can be monitored by a TextLCD screen which displays the IP Address of the controller (for future web server capabilities and rpc control) and the current Date/Time. The LCD will also indicate interrupts such as SMS send/receive actions.

Hardware Needed

1. The mbed NXPLPC 1768 microcontroller forced
2. Enfora 1308-50 GSM modem forced
3. Polulu 23201a Serial breakout board forced
4. DB9 cable forced
5. Appropriate DB9 Null Modem/Gender Changer if needed forced
6. Sparkplug RJ-45 Breakout Board

Connections

1. Connect the mbed to power and ground. forced
2. Power the GSM modem with a wall wart (6-40 VDC). forced
3. Ethernet Connection forced
4. Serial Connection between the GSM Modem and the mbed such that:

Set the GSM modem to 19.2K (use "AT+IPR=19200" in a terminal program, the GSM by default is set to autobaud but it sometimes does not work outside 115.2K). Handshaking lines can be disabled with the command "AT+IFC=0,0". Refer to the SAG+ AT Command Manual for more commands.