How to Make a Call using Keyboard, GSM Module and Arduino

The mobile phones have built –in GSM module which enables them to connect with any cellular network around the globe. The GSM stands for Global System for Mobile communications. In certain applications the microcontroller based systems has to be connected with the GSM network which will enable a user to control the system by sending messages or making a call. The systems can also send messages to the user to alert or inform about the status of the system running. In all such cases a separate GSM module is used rather than using the mobile phones.

There are GSM modules available which can do serial communication with microcontroller based systems. The communication is done by sending or receiving AT commands with the GSM module. This particular project demonstrates how to interface a GSM module and dial a call using the standard PS2 keyboard with the help of an Arduino board.

The PS2 keyboard can send the equivalent ASCII value of the key which has been pressed to a host device into which it is connected to. The PS2 Keyboard also uses a simple synchronous serial protocol called PS2 using only two wires for communication. Due to their simplicity in interfacing the PS2 keyboards and GSM modules are widely used with simple microcontroller based boards. 

How to Interface GPS with Arduino

Every single location in the entire globe can be specified in terms of geographical coordinates. The geographical coordinate is a system which specifies any given location on the earth surface as latitude and longitude. There are devices which can read the geographical coordinates of a place with the help of the signals received from a number of satellites orbiting the earth. The system of satellites which helps in the positioning of a place is called Global Positioning System (GPS). The devices which can read the geographical coordinates of a place with the help of at least four GPS satellites are called GPS Receiver or simply GPS module.

The GPS module continuously produces a set of data regarding the position of the earth surface where it is situated which includes the current position with respect to the equator of the earth in terms of Latitude and Longitude. This data can be decoded and printed into the readable format with the help of a microcontroller only. In this project the data regarding the geographical coordinate is extracted from the GPS output with the help of the Arduino. The Arduino can be used as a stand-alone board of which the output or inputs can be taken from the boards or given to the board. They can communicate using standard communication ports like USART, TWI, SPI etc. which enables them to be connected with various kinds of devices. The Arduino board is designed for easy prototyping and the IDE used for coding is very simple and provides so many libraries for interfacing with common external devices.