SIM300 GSM module interfacing

Hello everybody,

I am an arduino tinkerer, I want to interface my SIM300 GSM module with arduino uno board. My gsm module has only 4 pins Tx, Rx, Vcc, Gnd.
I have read the arduino tutorial
but it demonstrates the code with gsm shield & I have a bare GSM module with Tx, Rx pins. can you guide me how to interface my device so that I can Run the code?

Any help shall be highly appreciated. Thanks & regards.

have a bare GSM module with Tx, Rx pins. can you guide me how to interface my device so that I can Run the code?

With only 4 wires to connect, this doesn't seem too difficult. Unless I missed something. What part are you having trouble with?


I want to thak you for your response & apologise for my late response. Actually i was busy with another project these days [Project Completed] Arduino controlled Smart Reading Lamp - Project Guidance - Arduino Forum
I am glad that it is finally done.

With the GSM modem I wanted to build a security systems of a store room where inflamable gases are preserved.
The following components will be used...
Arduino Uno
MQ6 LPG gas sensor - to detect the intensity level of LPG gas (if any leakage happens)
Motors (To completely shut the doors & windows of the store room)
Relay circuit (To disconnect the power supply in the room & to ensure no spark can be generated to avoid explosion)
A Buzzer (For alarm)
GSM Modem (To inform the store keeper & fire fighters)

After developing the hardware of my existing project by this week I'll start working on this project. Need to digest some good tutorials, books & videos on how to control the motor via arduino because this seems the most challenging part.

Thank you.

What module do you have?

The official Arduino GSM module is wired to put the TX and RX on pins 2 and 3, and the GSM library uses Software Serial on these pins. To get your module working, I picture:

(1) power the GSM module. You will not be able to power it from your arduino, most likely, as it will need upwards of 1,000mA. You'll have to look at the docs for your module to know how to power it, exactly.

(2) connect the ground/negative supply of the GSM module to the ground of the arduino

(3) connect pin 3 to GSM TXD, pin 2 to GSM RXD.

Give the GSM library a try.

It may well not work since the official Arduino module is based on a Quectel baseband, not a Simcom SIM300 one. But the commands are all ETSI GSM 07.07 based, so it stands a chance to "just work".

There are popular module based on Simcom SIM900 chipsets. Likely you will find a a usable library if the Arduino doesn't work.