Robokits India SIM 800A GSM GPRS Module with RS232 Interface [RKI-2586] - The SIM800A modem has a SIM800A GSM chip and RS232 interface while enables easy connection with the computer or laptop using the USB to Serial connector or to the microcontroller using the RS232 to TTL converter.
Interfacing sim800 / sim900A GSM module with arduino Here describes the interfacing between a SIM 800 GSM / SIM 900A GSM module with an Arduino board via TTL serial communication. Arduino gsm module pinout Arduino pin GSM modem pin RX TX TX RX GND GND For a TTL serial connection, connect the pins from the GSM device to Arduino as, Rx pin to TX pin and TX pin to Rx pin. Or if the software serial is used, connect to the declared Transmitter and Receiver pins.
If the Arduino code uses the serial communication as Serial. Begin ( 9600 ), the TX and RX pins will be default TX and RX pins of the AVR microcontroller which is labelled on the Arduino UNO board. So just plug to TX pin (pin 1) and the RX pin (pin 0). E.g: – SoftwareSerial mySerial (2, 3); // RX digital pin 2, TX digital pin 3.
GSM modems may also have a female RS232 serial port for direct connection to PC. In order to work directly with hyper terminal or similar serial terminals using AT commands. GSM modem booting Insert the SIM card into the SIM socket of the module and lock it. The GSM module requires a considerable amount of power to establish a network connection, and for operations. So power from the Arduino board will not be enough for it. So an external power is required for most GSM modules.
The GSM module Commonly has a 12V DC input, which can be connected either via DC socket or through connector pins. Plug a 12V adapter into the Socket or power it by connector pins on the board. On powered up, the power LED gets ON and the Network Status LED starts to blink. The network LED blink every second and after when the Modem registers the network, the LED will blink in every 3 seconds. The GSM module takes some time, around 60 seconds to establish a connection with mobile networks. Send sms using gsm module with Arduino. Send SMS using push switch In this device whenever the switch is pressed, a text message (text in the code) will send to the number specified in the code.
![Sim800 Sim800](/uploads/1/2/5/6/125632821/659243547.jpg)
When the pushbutton is pressed, the Arduino sends the AT commands to the GSM module, for a text SMS; the GSM module works with the “AT commands”. Connect the TX, RX and GND pins from the Arduino to the GSM as labelled in the diagram.
Then connect the push switch between the 5V and pin2. Add a pull-down resistor across the pin2 and Ground. The Pin2 is configured as the input pin.
When the pin2 reads an active high state, the sketch inside the if condition will be executed. And the SMS sends. A variable called state is also added to the condition function of the program, it is to prevent multiple sending of SMS on a single switch press. The “if” condition becomes true only when the digitalRead at pin 2 is high and the value of variable state is ‘ 0 ‘. The value of variable state is initialized as ‘ 0 ‘.
On pressing the switch, the “if” condition becomes true, that the SMS sends and the state value set to ‘ 1 ‘. Only when the switch is released the state value sets back to ‘ 0 ‘. Only the switch press after the setback of the state to ‘ 0 ‘ makes the if condition true.
So a long press will not send multiple SMS, only press after a release sends the next SMS. That is, each consecutive press sends each SMS.