RDL SIM900A User manual

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GSM GPRS SIM900A MODEM
REV1.0
GPRS /GSM SIM900A MODEM
WITH ARDUINO COMPATIBLE
USER MANUAL

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GSM GPRS SIM900A MODEM
REV1.0
Contents
Overview......................................................................................................................................... 3
Features........................................................................................................................................... 4
Datasheets ....................................................................................................................................... 4
Basic AT Commands for Testing ................................................................................................... 5
GSM AT Commands:................................................................................................................. 5
GPRS Commands:...................................................................................................................... 6
MODULE SETUP .......................................................................................................................... 7
SAMPLE CODE:........................................................................................................................ 8
POWER MODES............................................................................................................................ 9
Power down mode....................................................................................................................... 9
Minimum Functionality Mode.................................................................................................... 9
Sleep mode.................................................................................................................................. 9
Wake up SIM900A from sleep mode ......................................................................................... 9
PINS OF GPRS /GSM SIM900A MODEM WITH ARDUINO COMPATIBLE....................... 10
NARATION OF GPRS /GSM SIM900A MODEM WITH ARDUINO COMPATIBLE........... 11
BLOCK DIAGRAMS................................................................................................................... 12
INTERFACING UNO AND GSM SHIELD............................................................................ 12
INTERFACING MICROCONTROLLER WITH GSM SHIELD EXTERNAL SERIAL PINS
................................................................................................................................................... 13
CODE............................................................................................................................................ 14
GSM POWER SAVING PIC CODE........................................................................................ 14
MODULE HANDLING ............................................................................................................... 15
DO'S AND DONT'S................................................................................................................. 15

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GSM GPRS SIM900A MODEM
REV1.0
Overview
GPRS /GSM SIM900A MODEM WITH ARDUINO COMPATIBLE
This is a very low cost and simple Arduino GSM and GPRS shield. We use the module
SIMCom SIM900A.
The Shield connects your Arduino to the internet using the GPRS wireless network. Just
plug this module onto your Arduino board, plug in a SIM card from an operator offering GPRS
coverage and follow a few simple instructions to start controlling your world through the
internet. You can also make/receive voice calls (you will need an external speaker and
microphone circuit) and send/receive SMS messages
There are two modules
1. GSM SHIELD WITH STACKABLE UNO HEADERS ON BOTH SIDES(WITH
NOMIC AND SPEAKER)
2. GSM SHIELD WITH SINGLE UNO HEADERS WITH MIC AND SPEAKER

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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 .
Stackable UNO headers
optional power on through microcontroller.
External serial pins.
Datasheets
AT Commands datasheet
https://drive.google.com/a/researchdesignlab.com/file/d/0BzrGD4zr88GnTkJwSll3dnhK
bTg/edit?usp=sharing
FTP Commands datasheet
https://drive.google.com/a/researchdesignlab.com/file/d/0BzrGD4zr88GnVkhacjUtY2tIU
2c/edit?usp=sharing
TCP/IP Commands datasheet
https://drive.google.com/a/researchdesignlab.com/file/d/0BzrGD4zr88GnUHRCQlJwUjd
WTVU/edit?usp=sharing

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GSM GPRS SIM900A MODEM
REV1.0
Basic AT Commands for Testing
GSM AT Commands:
TO CHECK THE MODEM:
AT ↲
OK
TO CHANGE SMS SENDING MODE:
AT+CMGF=1 ↲
OK
TO SEND NEW SMS:
AT+CMGS=”MOBILE NO.” ↲
<MESSAGE
{CTRL+Z}
TO RECEIVE SMS
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","[phone]",,"07/05/01,08:00:15+32",145,37
<MESSAGE
PREFERRED SMS MESSAGE STORAGE:
AT+CPMS=? ↲
+CPMS: (“SM”),(“SM”),(“SM”)
OK
AT+CPMS? ↲
+CPMS: “SM”,19,30,”SM”,19,30,”SM”,19,30
TO MAKE A VOICE CALL:
ATD9876543210; ↲
TO REDIAL LAST NO:
ATDL ↲
TO RECEIVE INCOMING CALL:
ATA ↲
TO HANGUP OR DISCONNECT A CALL:
ATH ↲
TO SET A PARTICULAR BAUDRATE:
AT+IPR=? ↲{To view the baud rate values}
AT+IPR=0 ↲{To set the modem to autobauding mode}
OPERATOR SELECTION:
AT+COPS=? ↲
OK
AT+COPS? ↲
+COPS: 0,0,”AirTel”
OK

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GSM GPRS SIM900A MODEM
REV1.0
AT+CRC SET CELLULAR RESULT CODES FOR INCOMING CALL INDICATION:
AT+CRC=? ↲
+CRC: (0-1)
OK
AT+CRC? ↲
+CRC: 0
OK
AT+CRC=1 ↲
OK
+CRING: VOICE
READ OPERATOR NAMES.
AT+COPN=? ↲
OK
AT+COPN ↲
+COPN: “472001″,”DHIMOBILE”
+COPN: “60500
+COPN: “502012″,”maxis mobile”
+COPN:
+COPN: “502013″,”TMTOUCH”
+COPN
+COPN: “502016″,”DiGi”
+COPN: “502017″,”TIMECel”"
+COPN: “502019″,”CELCOM GSM”
GPRS Commands:
Command Description
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 : power ON through Controller (Place Jumper on JP4 of GSM shield)
step 3 : power ON automatically (Place Jumper on JP3 of GSM shield)

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GSM GPRS SIM900A MODEM
REV1.0
step 4 : Press and hold power button (To turn on manually without jumper)
step 5 :compile and burn the sample code given below to UNO board and then mount the GSM
Shield.
SAMPLE CODE:
void setup()
{
Serial.begin(9600);
delay(5000);
}
void loop()
{
Serial.println("AT");
delay(1000);
Serial.println("AT+CMGF=1");
delay(1000);
Serial.println("AT+CMGS=\"1234567890\""); //CHANGE TO DESTINATION NUMBER
delay(1000);
Serial.print("hi");
Serial.write(26);
delay(1000);
}
Step 6 : Padding configuration
Short 3 and 2 by manual soldering to select hardware RX and TX(D0 and D1)
Or
Short 1 and 2 by manual soldering to select Software RX and TX (D2 and D3)
*default padding is set D0 and D1

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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 GPRS /GSM SIM900A MODEM WITH ARDUINO COMPATIBLE