Category: Arduino

Send and Receive SMS using arduino and GSM shield sim900.

by admin
Hi Please prepare the circuit as shown in image. code:
#include "SIM900.h"
//If not used, is better to exclude the HTTP library,
//for RAM saving.
//If your sketch reboots itself proprably you have finished,
//your memory available.
//#include "inetGSM.h"

//If you want to use the Arduino functions to manage SMS, uncomment the lines below.
#include "sms.h"

//To change pins for Software Serial, use the two lines in GSM.cpp.

//GSM Shield for Arduino
//this code is based on the example of Arduino Labs.

//Simple sketch to send and receive SMS.

int numdata;
boolean started=false;
char smsbuffer[160];
char n[20];

void setup()
     //Serial connection.
     Serial.println("GSM Shield testing.");
     //Start configuration of shield with baudrate.
     //For http uses is raccomanded to use 4800 or slower.
     if (gsm.begin(2400)) {
     } else Serial.println("\nstatus=IDLE");

     if(started) {
          //Enable this two lines if you want to send an SMS.
          if (sms.SendSMS("+919036634994", "Arduino SMS"))
          Serial.println("\nSMS sent OK");


void loop()
     if(started) {
          //Read if there are messages on SIM card and print them.
        /**  deprecated method
        if(gsm.readSMS(smsbuffer, 160, n, 20)) {
          //get 1st sms

Get the temperature and humidity from dht22 sensor(Part 1).

by admin
1.Connect pin 1 (on the left) of the sensor to +5V *NOTE: If using a board with 3.3V logic like an Arduino Due connect pin 1 to 3.3V instead of 5V! 2.Connect pin 2 of the sensor to whatever your DHTPIN is 3. Connect pin 4 (on the right) of the sensor to GROUND 4.Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor(As shown in image )