SIM900 GSM GPRS shield is based on a chip of SIM900 from SIMCOM and is compatible with Arduino and its clones. It is used to make and receive phone calls, send and receive SMS and connect to the internet using the GPRS network via UART using AT commands. It supports quad-band and can communicate through GSM 850 MHz, GSM 900 MHz, DCS 1800 MHz or PCS 1900 MHz networks. It has a power jack along with a toggle switch to use an external power supply.
SIM900 shield can be powered by a 5V power supply that can provide 2A current or 9V, 1A or 12V, 1A supply. It is equipped with a microphone and speakers jack for phone calls. At the backside of the shield, there is a sim card jack and a holder for a 3V CR1220 battery for the RTC (real-time clock). After insertion of sim and battery, the shield can be mounted on top of the Arduino board.
Features:
- Compatible with Arduino and its clones
- Quad Band 850 / 900/ 1800 / 1900 MHz GSM network
- Can send and receive SMS, MMS, GPRS and audio using GSM network.
- Supports UART interface
- AT commands
- Embedded TCP/UDP stack facility for uploading data to a web server
- RTC support
- Speaker and Headphone jacks
- Equipped with 12 GPIOs, 2 PWMs, and an ADC
Pin Description of SIM900 GSM GPRS
| Pins | Description |
| Power select | Select the power supply for GPRS shield(external power or 5v of Arduino) |
| Power jack | Connected to external 4.8-5V DC power supply |
| Antenna interface | Connected to an external antenna |
| Serial port select | Select either software serial port or hardware serial port to be connected to GPRS Shield |
| Hardware Serial | D0/D1 of Arduino |
| Software serial | D7/D8 of Arduino |
| Status LED | Tells whether the power of SIM900 is on |
| Net light | Tells the status of SIM900 linking to the net |
| UART of SIM900 | UART pins breakout of SIM900 |
| Microphone | To answer the phone call |
| Speaker | To answer the phone call |
| GPIO, PWM, & ADC | GPIO, PWM and ADC pins breakout of SIM900 |
| Power key | Power up and down for SIM900 |
Pins usage on Arduino:
| Pins | Arduino |
| D0 | Unused if you select software serial port to communicate with GPRS Shield |
| D1 | Unused if you select software serial port to communicate with GPRS Shield |
| D2-D6 | Unused |
| D7 | Used if you select software serial port to communicate with GPRS Shield |
| D8 | Used if you select software serial port to communicate with GPRS Shield |
| D9 | Used for software control the power up or down of the SIM900 |
| D10-D13 | Unused |
| D14-D19 (A0-A5) | Unused |
Specifications:
- Supply voltage: 3.4V-4.5V
- Low power consumption: 1.5mA(sleep mode)
- Industrial temperature range: -40⁰C to +85⁰C
- Class 4 (2 W @ 850 / 900 MHz) , Class 1 (1 W @ 1800 / 1900MHz)
- Dimensions: 8.5 X 5.7 X2cm(approx)
Applications and uses of SIM900 GSM GPRS
Sim900 shield can be used in a variety of IOT applications:
- Vehicle tracking
- Wireless sensor networks and remote weather stations
- Controlling of appliances remotely
- M2M(machine 2 machine) applications.
