DO'S AND DONT'S ................................................................................................................. 20
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GSM GPRS SIM900A MODEM
REV1.0
Overview
GSM GPRS SIM 900A module with Stub Antenna and SMA connector-USB
GSM/GPRS Modem-RS232 is built with Dual Band GSM/GPRS engine- SIM900A,
works on frequencies 900/ 1800 MHz. The Modem is coming with RS232 interface, which
allows you connect PC as well as microcontroller with RS232 Chip(MAX232). The baud rate is
configurable from 9600-115200 through AT command. The GSM/GPRS Modem is having
internal TCP/IP stack to enable you to connect with internet via GPRS. It is suitable for SMS,
Voice as well as DATA transfer application in M2M interface. The onboard Regulated Power
supply allows you to connect wide range unregulated power supply . Using this modem, you can
make audio calls, SMS, Read SMS, attend the incoming calls and internet through simple AT
commands
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GSM GPRS SIM900A MODEM
REV1.0
Features
Dual-Band GSM/GPRS 900/ 1800 MHz.
RS232 interface for direct communication with computer or MCU kit.
Configurable baud rate.
Power controlled using 29302WU IC.
ESD Compliance.
Enable with MIC and SPeaker socket.
With slid in SIM card tray.
With Stub antenna and SMA connector.
Input Voltage: 12V DC.
Jumper settings to choose between USB mini and rs232
AT+CMGD=1 ↲{to delete the message in buffer}
AT+CMGR=1 ↲ {to receive first message AT+CMGR=1}
{to receive second message AT+CMGR=2 and so on}
+CMGL: 1,"REC READ","+85291234567",,"07/05/01,08:00:15+32",145,37
<MESSAGE
AT+CGATT ↲ ATTACH/DETACH FROM GPRS SERVICE
AT+CGDCONT ↲ DEFINE PDP CONTEXT
AT+CGQMIN ↲ QUALITY OF SERVICE PROFILE (MINIMUM ACCEPTABLE)
AT+CGQREQ ↲ QUALITY OF SERVICE PROFILE (REQUESTED)
AT+CGACT ↲ PDP CONTEXT ACTIVATE OR DEACTIVATE
AT+CGDATA ↲ ENTER DATA STATE
AT+CGPADDR ↲ SHOW PDP ADDRESS
AT+CGCLASS ↲ GPRS MOBILE STATION CLASS
AT+CGEREP ↲ CONTROL UNSOLICITED GPRS EVENT REPORTING
AT+CGREG ↲ NETWORK REGISTRATION STATUS
AT+CGSMS ↲ SELECT SERVICE FOR MO SMS MESSAGES
AT+CGCOUNT ↲ GPRS PACKET COUNTERS
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GSM GPRS SIM900A MODEM
REV1.0
MODULE SETUP
step 1 : Insert SIMcard into the SIM slot.
step 2 : Plug in 12V -2A DC power adapter, power led is lit (place jumper between PWRkey
and on pin for only to turn ON automatically).
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GSM GPRS SIM900A MODEM
REV1.0
step 3 : Press and hold power button (To turn on manually without jumper)
step 5 : jumper setting for selecting mini USB or RS232
step 4 : Connect to PC through RS232 cable or miniUSB to USB cable
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GSM GPRS SIM900A MODEM
REV1.0
step 5 : open GSM/GPRS utility software ,choose appropriate COM port and use AT commands
listed in this manual for basic testing GPRS GSM/messaging and voice calling.
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GSM GPRS SIM900A MODEM
REV1.0
POWER MODES
Power down mode
SIM900A is set power down mode by “AT+CPOWD=0”
There are two methods for the module to enter into low current consumption status
Minimum Functionality Mode
Minimum functionality mode reduces the functionality of the module to a minimum and thus
minimizes the current consumption to the lowest level.
If SIM900A has been set to minimum functionality by “AT+CFUN=0”
If SIM900A has been set to full functionality by “AT+CFUN=1”
If SIM900A is set “AT+CFUN=4” to disable both the above functionality.
Sleep mode
We can control SIM900A module to enter or exit the SLEEP mode in customer
applications through DTR signal. When DTR is in high level and there is no on air and hardware
interrupt (such as GPIO interrupt or data on serial port), SIM900A will enter SLEEP mode
automatically. In this mode, SIM900A can still receive paging or SMS from network but the
serial port is not accessible.
Wake up SIM900A from sleep mode
Enable DTR pin to wake up SIM900A. If DTR pin is pulled down to a low level
This signal will wake up SIM900A from power saving mode. The serial port will be
active after DTR changed to low level for about 50ms.
Receiving a voice or data call from network to wake up SIM900A.
Receiving a SMS from network to wake up SIM900A.
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GSM GPRS SIM900A MODEM
REV1.0
PINS OF GSM GPRS SIM 900A module with Stub Antenna and SMA
connector-USB
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GSM GPRS SIM900A MODEM
REV1.0
NARATION OF GSM GPRS SIM 900A module with Stub Antenna and SMA
connector-USB