Interfacing Arduino with GSM Module

Getting Started

What is Arduino?

It's an open-source physical computing platform based on a simple microcontroller board which you can program by using the software provided by Arduino manufacturer by connecting it to your computer using USB cable.

For More Information Regarding Arduino, Visit its official Website: http://arduino.cc 

GSM/GPRS module

GSM/GPRS module is used to establish communication between a computer and a GSM/GPRS system. Global System for Mobile communication (GSM) is an architecture used for mobile communication in most of the countries. Global Packet Radio Service (GPRS) is an extension of GSM that enables higher data transmission rate. GSM/GPRS module consists of a GSM/GPRS modem assembled together with power supply circuit and communication interfaces (like RS-232, USB, etc) for computer. The MODEM is the soul of such modules.

Wireless MODEMs

Wireless MODEMs are the MODEM devices that generate, transmit or decode data from a cellular network, for establishing communication between the cellular network and the computer. These are manufactured for specific cellular network (GSM/UMTS/CDMA) or specific cellular data standard (GSM/UMTS/GPRS/EDGE/HSDPA) or technology (GPS/SIM). Wireless MODEMs like other MODEM devices use serial communication to interface with and need Hayes compatible AT commands for communication with the computer (any microprocessor or microcontroller system).

GSM/GPRS MODEM 

GSM/GPRS MODEM is a class of wireless MODEM devices that are designed for communication of a computer with the GSM and GPRS network. It requires a SIM (Subscriber Identity Module) card just like mobile phones to activate communication with the network. Also they have IMEI (International Mobile Equipment Identity) number similar to mobile phones for their identification.

 A GSM/GPRS MODEM can perform the following operations:

1.      Receive, send or delete SMS messages in a SIM.

2.      Read, add, search phonebook entries of the SIM.

3.      Make, Receive, or reject a voice call.

The MODEM needs AT commands, for interacting with processor or controller, which are communicated through serial communication. These commands are sent by the controller/processor. The MODEM sends back a result after it receives a command. Different AT commands supported by the MODEM can be sent by the processor/controller/computer to interact with the GSM and GPRS cellular network.

 GSM/GPRS Module

A GSM/GPRS module assembles a GSM/GPRS modem with standard communication interfaces like RS-232 (Serial Port), USB etc., so that it can be easily interfaced with a computer or a microprocessor / microcontroller based system. The power supply circuit is also built in the module that can be activated by using a suitable adaptor.

There are diffirent versions of GSM Modules available in the market.

Arduino GSM shield can also be used which makes the work easy since we can use Arduino GSM Library.

for further detail you can visit  http://arduino.cc/en/Tutorial/HomePage

Block Diagram

Interfacing the Modem with ARDUINO

In this section we will discuss about interfacing SIM900 GSM/GPRS module with Arduino

SIM900 GSM/GPRS module Hardware

To interface GSM module with Arduino three connections have to be made between them along with separate power supply.
The three connections are:

     1.      Connect TX pin of SIM900 GSM/GPRS module to TX pin of Arduino,

     2.      Connect RX pin of SIM900 GSM/GPRS module to RX pin of Arduino,

     3.      Connect GND pin of SIM900 GSM/GPRS module to GND pin of Arduino

*Note that GSM board should be powered with separate power source because current from the Arduino will not be enough to drive the GSM Module.

Circuit Configuration

Description

1) Insert SIM card 

Open the SIM cardholder by sliding it as per the arrow mark and lift up. Insert the SIM card , so as to align the chamfered corner suits in card holder .After inserting the SIM card, lock the holder by sliding it to the opposite direction of arrow mark. 

2) Connect The Antenna

Fix the Supplied RF antenna to the SMA Antennae connector and tighten it by Rotating the Nut ( Never rotate the antennae for tightening ).

3) Connect the Pins 

Connect the GSM modem as per the circuit diagram provided 

4) Power the Modem 

Power the modem from suitable power supply, which is having enough current capacity (>1A).

5) Check the Status of the LEDs 

PWR LED - Red LED will lit immediately 

STS LED - Green LED will lit after 1-2 seconds 

NET LED -Blue LED will starts to blink in fast for few seconds(Searching For Network) and becomes slow blinking once the Modem registers with the Network.

6) Network LED

The Network LED indicates the various status of GSM module eg. Power on, Network registration & 

GPRS connectivity. When the modem is powered up, the status LED will blink every second. After the Modem registers in the network (takes between 10-60 seconds), LED will blink in step of 3 seconds. At this stage you can start using Modem for your application. 

7) Baud rate

The Baud rate supported by the modem is between 9600 and 115200. Make sure the host system is set to the supported baud rate. 

NOTE

*The modem automatically sets to the baud rate of the first command sent by the host system after it is powered up. User must first send “A” to synchronize the baud rate. It is recommended to wait 2 to 3 seconds before sending “AT” character. After receiving the “OK” response, Your Device and GSM Modem are correctly synchronized. So there is no need for setting the baud rate using commands.

*Before You Start using the modem, please make sure that the SIM card you inserted support the needed features and there is enough balance in SIM.!!!

                    click here to view the DATA SHEET of SIM900 GSM.GPRS MODULE
                                                     Get one(form Nepal)

#1 Invisible Broken-Wire Detector

ABSTRACT

A device works only when there is proper connection between the circuit elements. Conducting wires serve in making complete connection. But, when the conductor has fault in it, it isn't capable of conducting due to breakage at some point in its length, the device may no longer operate.

Portable loads such as video cameras, halogen flood lights, electrical irons, hand drillers, grinders, and cutters are powered by connecting long 2- or 3-core cables to the mains plug. Due to prolonged usage, the power cord wires are subjected to mechanical strain and stress, which can lead to internal snapping of wires at any point. In such a case most people go for replacing the core/cable, as finding the exact location of a broken wire is difficult.

In 3-core cables, it appears almost impossible to detect a broken wire and the point of break without physically disturbing all the three wires that are concealed in a PVC jacket. The circuit presented here can easily and quickly detect a broken/faulty wire and its breakage point in 1-core, 2-core, and 3-core cables without physically disturbing wires.

Finding out the exact location of breakage can be a problem to the user as the wires are usually insulated by PVC or plastic jacket making the conducting wires inside them invisible.

INTRODUCTION

Invisible Broken wire detector is an instrument, very useful under these circumstances since it can easily detect the location of internal snapping without contact and physical disturbance.When it senses the breakage in the faulty wire the LED in the instrument turns off, the user knows the location of the fault and the broken section of wire can be replaced easily.

OBJECTIVE    

Our basic aim in this project is to locate the exact position of breakage in conducting wires concealed in PVC jacket without physically damaging the jacket thus reducing the waste of time as well as resources.

BLOCK DIAGRAM AND GENERAL DESCRIPTION

                               Invisible Broken-Wire Detector Block Diagram

General Description

To detect the exact location of the broken wire inside the PVC jacket we employ our circuit with a hex inverter  CMOS which uses its actions to control an oscillator which in return detects the presence of ac current and thus shows us the exact location till where the wire is intact and allowing the passage of current through it.

CIRCUIT DIAGRAM

COMPONENTS REQUIRED AND THEIR DESCRIPTION

1) CMOS hex inverter CD4069UB
The CD4069UB consists of six inverter circuits and is manufactured using complementary MOS (CMOS) to achieve wide power supply operating range, low power consumption, high noise immunity, and symmetric controlled rise and fall times.
2) 1N4148 High speed switching diodes
These have high switching speed up to4ns and have continuous reverse voltage upto 100 volts, repetitive peak reverse voltage; max:100V and repetitive peak forward current; max:450mA.
3) BC547 transistor
4) Resistors
    47 ohm
    1M ohm
    560 ohm
    220 ohm
5)1.5 x 2 AG13 or LR44 type button cells
6) LEDs
7) Bread board
8) 2200P capacitor
9) Connecting wires and probe
10)Switch

FEATURES

1) Wide supply voltage range: 3V to 15V,
2) High noise immunity,
3) Operating temperature range :  -55 C to  +125 C,
4) Portable,
5)No physical disturbance,
6) Contactless detection,
7) Low power requirements,
8)Accurate,
9)Easy to use ,
10)Useful and handy instrument.

RESULT AND DISCUSSIONS

Thus the circuit was made successfully which can easily detect broken point in the wire inside PVC jacket without physically disturbing it.
The whole circuit can be accommodated in a small PVC pipe and used as a handy broken-wire detector. This will make the circuit more compact and east to handle. The handy broken-wire is portable and less prone to damage.

CONCLUSIONS AND RECOMMENDATIONS

The circuit is made cheap and best. It would not only be able in reducing wastage of time but resources too.
Thus using just a hex inverter and few resistors we are able to construct a device which can easily detect a faulty broken wire and thus save the extra cost of a user which is incurred on replacing it which is otherwise too difficult.

FUTURE SCOPE

We can use an inverter in between the led and the oscillator which will then turn on the LED only when the broken point is detected and keeping it off when wire is not broken. By making this change we can make our detector more user-friendly which now directly shows the broken point.

REFERENCE
www.google.com
www.extermecircuits.net

A little bit of start :)