One of the essential elements of building IoT project is the ability to connect devices. Wi-Fi and Bluetooth are good low cost choices, but they work only at close ranges, or in hotspot areas. When the device needs to be at a remote location GSM is a good and easy to setup option.
In this Instructable, I will show you how easy it is to send and receive SMS messages over GSM with Arduino.
In the following Instructables, I will also show you how you can connect over GSM to Internet and access servers, and how you can handle voice calls.
Step 1: Components
- One Arduino Mega (You can use other boards, but it is best to use a board that has 2 or more serial ports. The project can be modified to use Software Serial, but using a hardware serial is recommended)
- One SIM900 based GSM Shield or compatible Shield or Module with installed SIM Card (Picture 2) (I used a Version 1.0 GSM/GPRS Shield from Seeed Studio)
- 2 Female-Male jumper wires
Step 2: Connect the GSM Shield to Arduino
- Remove l' jumper Caps from the GSM Shield‘s RX and TX Selection Jumpers (Picture 1)
- Plug the GSM Shield on the top of l' Arduino Mega
- Connect the Male End of a Male-Female jumper wire (Orange wire) to the RX1 Pin of the Arduino Mega (Pictures 2 and 3)
- Connect the Male End of a Male-Female jumper wire (Brown wire) to the TX1 Pin of the Arduino Mega (Pictures 2 and 3)
- Connect the Female end of the RX1 wire (Orange wire) to the center pin of the RX Selection Jumper of the GSM Shield (Picture 4)
- Connect the Female end of the TX1 wire (Brown wire) to the center pin of the TX Selection Jumper of the GSM Shield (Picture 4)
- Picture 5 shows the installed and connected GSM Shield
Read more: Send and Receive SMS with GSM SIM900 Arduino Shield
French 
English