SIM900/SIM900A GSM/GPRS Minimum System Module

From ITEAD Wiki
Jump to: navigation, search


GPRS module.jpg

GPRS module is a breakout board and minimum system of SIM900 Quad-band/SIM900A Dual-band GSM/GPRS module. It can communicate with controllers via AT commands (GSM 07.07 ,07.05 and SIMCOM enhanced AT Commands). This module supports software power on and reset.

Go shopping SIM900/SIM900A GSM/GPRS Minimum System Module (IM120525010)


  • Quad-Band 850/ 900/ 1800/ 1900 MHz
  • Dual-Band 900/ 1900 MHz
  • GPRS multi-slot class 10/8GPRS mobile station class B
  • Compliant to GSM phase 2/2+Class 4 (2 W @850/ 900 MHz)
  • Class 1 (1 W @ 1800/1900MHz)
  • Control via AT commands (GSM 07.07 ,07.05 and SIMCOM enhanced AT Commands)
  • Low power consumption: 1.5mA(sleep mode)
  • Operation temperature: -40°C to +85 °C



PCB size 71.4mm X 66.0mm X1.6mm
Indicators PWR, status LED, net LED
Power supply 5V
Communication Protocol UART
RoHS Yes

Electrical Characteristics

Parameter Min. Typical Max. Unit
Power voltage (Vsupply) 4.5 5.5 VDC
Input voltage VH 0.7VCC 5.5 V
Input voltage VL -0.3 0 0.3VCC V
Current Consumption (pulse) - 2000 mA
Current Consumption (continuous) 500 mA
Baud rate 115200 bps


GPRS module1.jpg

Interface Pin Description
Rst 1 Reset the SIM900 module
P 2 Power switch pin of SIM900 module
Tx 3 UART data output
Rx 4 UART data in
DT 5 Debug UART data output
DR 6 Debug UART data input
- 7 GND
+ 8 VCC


Power on GPRS module

User can power on the GPRS module by pulling down the PWR button or the P pin of control interface for at least 1 second and release. This pin is already pulled up to 3V in the module internal, so external pull up is not necessary. When power on procedure is completed, GPRS module will send following URC to indicate that the module is ready to operate at fixed baud rate.

Indicator LED and Buttons:

NETSTATUS: The status of the NETSTATUS LED is listed in following table:

Status Description
Off SIM900 is not running 64ms On/800ms
Off SIM900 not registered the network
64ms On/3000ms Off SIM900 registered to the network
64ms On/300ms Off GPRS communication is established

STATUS: Power status of SIM900.

PWR: Power status of GPRS module.

PWR: After the GPRS module power on, you need to press the POWER button for a moment to power on the SIM900 module.

RESET: Reset the SIM900 module.


In some countries where dual band exists, we recommend to use SIM900A to reduce costs. For the country list, please click here.




At command

GSM GPRS GPS Bluetooth for SIM800/808/900/908 Library

File:SIM900_MMS_AT Command Manual_V1.04.pdf

Useful Links

Jason Garland's GitHub Page <GSM Library for the SIM900 chip and the GBoard Arduino GSM development board>

MarcoMartines' GitHub Page <GSM/GPRS & GPS Shield Library for modules using SIM900/SIM908>

SIM900 firmware upgrade, please refer to the following link: