Getting Started with SainSmart SIM900 GPRS (Autosaved)

Getting Started with SainSmart SIM900 GPRS/GSM Module

Document Title Getting Started with SainSmart SIM900 Module

Version: 1.00 Date October 20, 2015

Status Draft

Document Control ID: Getting_Stated_with_SIM900_Ver1.00

Table of Contents

1 Introduction ........................................................................................................................................... 4

2 Hardware Requirements........................................................................................................................ 4

3 Software Requirements ......................................................................................................................... 4

4 Connecting to a Computer..................................................................................................................... 5

4.1 Setup .............................................................................................................................................. 5

4.2 Sending Text Messages .................................................................................................................. 7

4.3 Connecting to the Internet .......................................................................................................... 13

5 Connecting to an Arduino .................................................................................................................... 13

5.1 Setup ............................................................................................................................................ 13

5.2 Sending Text Messages ................................................................................................................ 13

5.3 Connecting to the Internet .......................................................................................................... 13

6 Connecting to a Microcontroller ......................................................................................................... 13

6.1 Setup ............................................................................................................................................ 13

6.2 Sending Text Messages ................................................................................................................ 13

6.3 Connecting to the Internet .......................................................................................................... 13

7 Connecting to a RaspberryPi ............................................................................................................... 13

7.1 Setup ............................................................................................................................................ 13

7.2 Sending Text Messages ................................................................................................................ 13

7.3 Connecting to the Internet .......................................................................................................... 13

1 Introduction The SainSmart Sim900 Module is a “Plug and Play” module developed by SainSmart. The module is built

on the SIM900 GRPS/GSM modem built by SimCom, a SIM Tech company. The module has the following

features among others:

Making and accepting phone calls

Sending and receiving text messages

Connecting to the internet.

Uploading and downloading data.

Interfacing with KeyPads

Interfacing with LCDs

Interfacing with microphones

Support for Speakers

Support for connecting to computers and embedded microcontrollers.

This documentation will show how the SIM900 can be used to interface with a computer, an Arduino, a

RaspberryPi and a Microntroller.

2 Hardware Requirements The following hardware will be required for interfacing with the SainSmart Simcom SIM900 Module.

USB to USART cable.

5V Power Supply

Connecting Wires (male to female jumper cables)

SIM Card

SIM Adapter in case of a microSim

3 Software Requirements In this documentation, the following software are used.

TeraTerm

Putty

ATMEL Studio 6

Arduino

4 Connecting to a Computer 4.1 Hardware Setup The SainSmart Sim900 Module can be connected to a computer using a USB to USART cable as shown

below.

The wires in the cable are as follows:

Color Code Wire Name

RED 5V

BLACK GND

GREEN TXD

WHITE RXD

There are many versions of this cable. I prefer the one displayed above. An Alternative is shown below.

The connection configuration is as follows:

USB TO USART Cable/Module SainSmart Sim900 GRPS/GSM Module

5V 5V (Power or +)

GND GND ( - ) RX (Receiver Pin) TX (Transmitter Pin)

TX (Transmitter Pin) RX (Receiver Pin)

Table showing connection configuration

The picture below shows the setup when connected using the USB to USART cable.

Configuration for connecting the SainSmart Sim900 to a computer using the USB to USART cable.

Connect the USB end to the USB port on the computer and allow for the drivers to install.

4.2 Turning on the Modem

Once the drivers for the USB to USART cable are installed, you will get a message saying that the drivers

were successfully installed and that the device is ready for use. If the message says that the drivers

failed to installed, unplug the cable and reinsert it in a different USB port.

To turn on the modem, simply push down the power button and hold it for 3 seconds. A green light

(LED) should come on, followed by another green flashing LED.

4.3 Software Setup To interface with the SIM900 GPRS Module a terminal software is required. Terminal Software include

TeraTerm, HyperTerm and PuTTY.

This documentation uses TeraTerm and PuTTY.

TeraTerm can be downloaded from: http://en.osdn.jp/projects/ttssh2/downloads/63767/teraterm-

4.88.exe/

PuTTY can be downloaded from: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

After installing the software; it must be configured to work with the Modem.

The screen shots below show the steps for configuring TeraTerm for communicating with the

SainSamart SimCom Sim900 GPRS/GSM Module.

1. Open TeraTerm and Click on the Serial Radio Button. This must be done after connecting the

USB to Serial Cable to the USB port of the computer.

2. Navigate to the Menu bar.

3. Select Terminal under the Setup tab.

4. Use the drop down to select “AUTO” beside the Receive option and “CR+LF” beside the

Transmit option.

5. Click OK.

6. Go back to the Menu bar and select Serial port….

7. Ensure the correct Port is selected.

8. Change the Baud Rate to 115200

9. Click OK.

10. Type “AT” at the black screen. If you see “OK” then the setup is complete.

11. In order to save the settings click on the setup tab and select Save setup….

12. Type in a file name and click the “Save” button.

13. You are now ready to start using the SainSmart GPRS GSM Modem.

4.4 Sending Text Messages A useful resource when working with the SainSmart SIM900 GPRS Modem is the AT Command Set from

SIMCOM Wireless. There are many syndications of the document online. The extended document can

be downloaded from http://garden.seeedstudio.com/images/a/a0/SIM900_ATC_V1_00.pdf

To send a text message the following commands must be entered at the black screen of the TeraTerm

software after setup. I use the following format in referring to commands entered into Tera Term and

the responses gotten from the modem.

Command: “This is what the user types into TeraTerm”

Response: “This is the response form the modem”

Notes: These are notes about the command and the response. The User does not type these in

the terminal software nor does the modem give this as part of the response.

Example:

Command: AT

Response: OK

Notes: “AT” is the standard command used to check if the modem is correctly configured and

connected to another device such as a computer or a microcontroller. If the response is “OK”

then the modem is correctly configured and connected. If there is no response, then either the

hardware is not correctly connected or the terminal software is not correctly configured.

To sending a text message, enter the following commands one after the other into the terminal

software (TERA TERM):

Command: AT

Response: OK

Notes: See example.

Command: AT+CMGF=1

Response: OK

Notes: The command “AT+CMGF=1” is used to select the message format. Setting CMGF=1 selects text

mode, setting CMGF =0 selects PDU mode. Refer to the SIM900_ATC_V1_00.pdf file for further

information and associated commands.

Command: AT+CMGS=”XXXXXXXXXX”

Response: >

Command: The text message you intend to send followed by holding Ctrl+Z

Response: +CMGS: 138

OK

Notes: The command “AT+CMGS=”XXXXXXXXXX” is used to send a text message to the number (XXX)

XXX-XXXX. The response is a prompt ( > ). The user can them type the message he wishes to

send. To send the text message, the user must hold down the ctrl key and the Z key.

Note that the destination number must be in quotes (“”). Also, note that is they are not in

quotes, the Modem responds with “ERROR”

4.5 Receiving and Reading Text (SMS) Messages

4.6 Connecting to the Internet

5 Connecting to an Arduino 5.1 Setup

5.2 Sending Text Messages

5.3 Connecting to the Internet

6 Connecting to a Microcontroller 6.1 Setup

6.2 Sending Text Messages

6.3 Connecting to the Internet

7 Connecting to a RaspberryPi 7.1 Setup

7.2 Sending Text Messages

7.3 Connecting to the Internet

8