AN2385 Freescale Semiconductor / Motorola, AN2385 Datasheet - Page 3

• Manufacturer Part Number: AN2385
• Description: GPRS Wireless Internet Connectivity Using DragonBall and Palm OS Based PDAs Application Note
• Manufacturer: Freescale Semiconductor / Motorola

Figure 1 illustrates the GUI command buttons. When a button is clicked, the PDA interacts with the mobile
phone by sending modem AT commands.
3.2 Modem AT Commands
Any data terminal equipment (DTE) device, when communicating with a modem, uses a set of commands
to configure and control the modem. This set of commands is called AT commands. “AT” refers to the
command prefix (ATtention sequence) that precedes each command to the modem. With the exception of
“A/”, all commands must be preceded by “AT” and end with a carriage return (0x0D).
Detailed information on modem AT commands is widely available. This section explains the set of AT
commands used in this application.
3.2.1 AT Commands Used in the GSM-GPRS Application
Three groups of AT commands are used in this application:
3.2.1.1 AT Command for Mobile Phone Key Emulation
When the PDA sends an phone key emulation AT command, the mobile phone device responds as if an
actual key on its own keypad had been pressed. By implementing the AT commands for the entire set of
keys on the mobile phone, a programmer can control the phone from the PDA through the RS-232 port.
MOTOROLA
the command AT+CKPD=e is
sent.
When this button is clicked,
•
•
•
Commands to emulate mobile phone’s key presses
Commands to control and configure the modem
Commands to do GPRS-related configuration
OFF Button
The GSM-GPRS application has been tested with the Motorola
Timeport™ 280 phone. However, other Motorola GSM/GPRS-enabled
phones use the same set of AT commands. Therefore, the application is
expected to work without modification with those phones.
GPRS Wireless Internet Connectivity Application Note
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 1. GSM-GPRS Application GUI
Go to: www.freescale.com
NOTE:
TALK Button
Numeric Buttons
sends AT commands to initialize
WWW Button
When this button is clicked, the program
the phone for GPRS-based Internet
access.
After initialization, the Eudora
browser is called programatically.
When any of the numeric buttons is clicked,
the corresponding ASCII decimal value
represented as character string is sent by the
program as AT command AT+CKPD=xx.
When this button is clicked, the program
sends the command AT+CKPD=s
GSM-GPRS Application
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