Overview

IComsat is a GSM/GPRS shield for Arduino and based on the SIM900 Quad-band GSM/GPRS module. It is controlled via AT commands (GSM 07.07 ,07.05 and SIMCOM enhanced AT Commands), and fully compatible with Arduino / Iteaduino and Mega.

Features

  • Quad-Band 850/900/1800/1900MHz
  • GPRS multi-slot calss 10/8
  • GPRS mobile station class B
  • Compliant to GSM phase 2/2+
  • Class 4 (2W@850/900MHz)
  • Class 1 (1W@1800/1900MHz)
  • Control via commands (GSM 07.07, 07.05 and SIMCOM enhanced AT Commands)
  • Short message service
  • Free serial port selection
  • All SIM900 pins breakout
  • RTC supported with Super Cap
  • Power on/off and reset function supported by Arduino interface

Specifications

PCB size77.2mm X 66.0mm X 1.6mm
IndicatorsPWR, status LED, net status LED
Power supply9~20V, compatible with Arduino
Communication ProtocolUART
RoSHYes

Electrical Characteristics

ParameterMin.TypicalMax.Unit
Power voltage (Vlogic)4.555.5VDC
Input voltage (Vsupply)9-20V
Input voltage VH4.555.5V
Input voltage VL-0.300.5V
Current Consumption(pulse)--2000mA
Current Consumption(Continues)500mA
Baud rate9600bps

Hardware

IM120417009_IComSat.jpg

Figure 1 Top Map

InterfacePinDescription
GPIOs1VDD
GPIOs2GND
GPIOs3GPIO1
GPIOs4GPIO2
GPIOs5GPIO3
GPIOs6GPIO4
GPIOs7GPIO5
GPIOs8GPIO6
GPIOs9GPIO7
GPIOs10GPIO8
GPIOs11GPIO9
GPIOs12GPIO10
GPIOs13GPIO11
GPIOs14GPIO12
GPIOs15GND
GPIOs16VDD
UART1GND
UART2DTR
UART3RI
UART4DCD
UART5CTS
UART6RTS
UART7TXD
UART8RXD
IIC&PWM1GND
IIC&PWM2GND
IIC&PWM3IIC_SCL
IIC&PWM4IIC_SDA
IIC&PWM5PWM2
IIC&PWM6PWM1
IIC&PWM7GND
IIC&PWM8GND
Debug_Port1GND
Debug_Port2PERKEY
Debug_Port3DBG_RXD
Debug_Port4DBG_TXD

VDD = 3.0V

Note1: the operation level of the port is 3.0V

Installation

UART Multiplexer (For free UART connection setting)

You can use the jumper to connect the TXD and RXD pins on SIM to any pins of Arduino D0 – D7.

IComsat1.jpg

When using the connection as Figure 4, the SIM900 connect to the ATMega328 chip on board.

IComsat2.jpg

When you using the connection as Figure 5, the SIM900 connect with the FT232RL chip, and the FT232RL connect to PC by USB. Whit this configuration you can use the serial software on PC to control or configure the SIM900 module.

IComsat3.jpg

Except the 2 configurations above, you can connect the TXD and RXD to any other pins from D0-D1, and using the software-serial library to control the SIM900 moudle.

IComsat4.jpg

Com Switch

There is a com switch for selecting the communicate port to UART port or Debug port of SIM900 module as the following figure 7. When connect to the SIM900 debug port, the UART multiplexer just can be set as Figure 4 or 5.

IComsat5.jpg

RI Behavior Output

There is a Jumper for configuration of RI, one to connect D2, another to connect D14.

StatusRI response
StandbyHigh
Voice callThe pin is changed to low. When any of the following events occur, the pin will be changed to high: (1) Establish the call (2) Hang up the call
Data callThe pin is changed to low. When any of the following events occur, the pin will be changed to high: (3) Establish the call (4) Hang up the call
SMSThe pin is changed to low, and kept low for 120ms when a SMS is received. Then it is changed to high
URCThe pin is changed to low, and kept low for 120ms when some URCs are reported. Then it is changed to high.

The behavior of the RI pin is shown in the following figure when SIM900 module is used as a receiver.

IComsat6.jpg

When the IComSat is used as caller, the RI will remain high.

Indicator LED and Buttons

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

StatusDescription
OffSIM900 is not running
64ms On/800ms OffSIM900 not registered the network
64ms On/3000ms OffSIM900 registered to the network
64ms On/300ms OffGPRS communication is established

STATUS: Power status of SIM900. PWR: Power status of IcomSat.

SIM900-POWER: After the IcomSat power on, you need to press the SIM900-POWER button for a moment to power on the SIM900 module. The pin 9 of Arduino interface is connecting to PWRKEY, and a high pulse with 500ms wide can power on/off it.

Sim900-RST: Reset the SIM900. The D8 of Arduino interface is connecting to RESRT of SIM900, and a high pulse with 500ms wide can power on/off it.

Arduino-RST: Reset the Arduino.

Software Notes

1. User must wait URC “CALL READY”(with fixed baud rate) then you can operate SIM card when user powers on the module, or can use AT+CCALR to inquire the states of “CALL READY”

2. When user meets error 512 or 515, First user should check if operate SIM card before “CALL READY”, and second should check if memory of SIM card is full.

Download

Datasheet for IComSat

SIM900 At Command Manual V1.03

SIM900 Hardware Design V2.00

SIM900 Reference Design Guide

SIM900 Schematic Ref

Schematic for IComSa

Library for GSM Shield

Useful Links

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

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

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ICOMSAT

  • Brand: Itead Studio
  • Product Code: IM120417009
  • Availability: In Stock
  • 60.03€
  • 42.35€

  • Ex Tax: 35.00€

Tags: GPRS ARDUINO ICOMSAT SIM900