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Wanted to share this snippet of code which I used to display a decimal numbers binary representation. It is quite self explanatory and easy to understand.

/**
  * Turns a decimal value to its binary representation
  */
char* dec2binWzerofill(unsigned long Dec, unsigned int bitLength){
    return dec2binWcharfill(Dec, bitLength, '0');
}

char* dec2binWcharfill(unsigned long Dec, unsigned int bitLength, char fill){
  static char bin[64];
  unsigned int i=0;
unsigned int j;
  while (Dec > 0) {
    bin[32+i++] = ((Dec & 1) > 0) ? '1' : fill;
    Dec = Dec >> 1;
  }

  for ( j = 0; j< bitLength; j++) {
    if (j >= bitLength - i) {
      bin[j] = bin[ 31 + i - (j - (bitLength - i)) ];
    }else {
      bin[j] = fill;
    }
  }
  bin[bitLength] = '';

  return bin;
}

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Need to measure water quality and other parameters?  DF Robot’s Analog pH Meter Kit is  specially designed for simple interface and has convenient and practical connector and a bunch of features. Get pH measurements at ± 0.1pH (25 ℃). For most hobbyist this great accuracy range and it’s low cost makes this a great tool for biorobotics and other projects! It has an LED which works as the Power Indicator, a BNC connector and PH2.0 sensor interface. To use it, just connect the pH sensor with BND connector, and plug the PH2.0 interface into the analog input port of any micro-controller.

The Wiki page  has a sample code for using this kit with arduino,  along with schematic, specifications, features ,precautions and setup Instructions. The arduino Interfacing is simple and the schematic and code is available on the wiki page.

PH_meter_connection1_(1)

Interfacing with a pic is also straight forward, Shawon Shahryiar shared his project where he used a PIC16F684. Below is the demonstration video and code.

/*
Coder: Shawon Shahryiar
https://www.facebook.com/groups/ArduinoBangla/
https://www.facebook.com/groups/microarena/
https://www.facebook.com/MicroArena
 */


#include <16F684.h>

#device *= 16
#device ADC = 10

#fuses NOWDT, INTRC_IO, PROTECT, PUT, CPD
#fuses NOBROWNOUT, NOMCLR, NOIESO, FCMEN

#use delay (internal = 4MHz)


#include "lcd.c"


#define const_A 0.00171016
#define LED	pin_C3


const unsigned char symbol[16] ={
    0x00, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x00, 0x00,
    0x00, 0x00, 0x0E, 0x0E, 0x0E, 0x00, 0x00, 0x00
};


void setup();
void lcd_symbol();
unsigned long adc_avg();
void show_bar(unsigned char value);

void main() {
    unsigned char samples_A = 0x00;
    unsigned char samples_B = 0x00;
    unsigned long temp = 0x0000;
    unsigned long avg = 0x0000;
    unsigned long buffer[10];
    float pH_value = 0.0;

    memset(buffer, 0x00, sizeof (buffer));

    setup();

    while (TRUE) {
        for (samples_A = 0; samples_A < 10; samples_A++) {
            buffer[samples_A] = adc_avg();
            delay_ms(9);
        }

        for (samples_A = 0; samples_A < 9; samples_A++) {
            for (samples_B = (1 + samples_A); samples_B < 10; samples_B++) {
                if (buffer[samples_A] > buffer[samples_B]) {
                    temp = buffer[samples_A];
                    buffer[samples_A] = buffer[samples_B];
                    buffer[samples_B] = temp;
                }
            }
        }

        avg = 0;

        for (samples_A = 3; samples_A < = 6; samples_A++) {
            avg += buffer[samples_A];
        }

        avg >>= 2;

        pH_value = (avg * const_A);

        lcd_gotoxy(1, 1);
        printf(lcd_putc, "pH Value: %2.2g ", pH_value);
        show_bar(((unsigned char) pH_value));
    };
}

void setup() {
    disable_interrupts(GLOBAL);
    setup_WDT(WDT_off);
    setup_oscillator(OSC_4MHz);
    setup_comparator(NC_NC_NC_NC);
    setup_ADC(ADC_clock_div_8);
    setup_ADC_ports(sAN0);
    set_ADC_channel(0);
    setup_CCP1(CCP_off);
    setup_timer_0(T0_internal);
    setup_timer_1(T1_disabled);
    setup_timer_2(T2_disabled, 255, 1);
    set_timer0(0x00);
    set_timer1(0x0000);
    set_timer2(0x00);
    lcd_init();
    lcd_symbol();
    delay_ms(4000);
}

void lcd_symbol() {
    unsigned char s = 0;

    lcd_send_byte(0, 0x40);

    for (s = 0x00; s < = 0x0F; s++) {
        lcd_send_byte(1, symbol[s]);
    }

    lcd_send_byte(0, 0x80);
}

unsigned long adc_avg() {
    unsigned char samples = 4;
    unsigned long avg = 0;

    while (samples > 0) {
        read_adc(adc_start_only);
        while (!adc_done());
        avg += read_adc(adc_read_only);
        samples--;
    }
    avg /= 4.0;

    return avg;
}

void show_bar(unsigned char value) {
    unsigned char x_pos = 0;

    for (x_pos = 1; x_pos < = 16; x_pos++) {
        lcd_gotoxy(x_pos, 2);
        lcd_putc(0);
    }

    lcd_gotoxy((value + 1), 2);
    lcd_putc(1);

    output_toggle(LED);
    delay_ms(100);
} 

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The simplest and easiest way to charge a battery with a solar panel is to connect the panel directly to the battery. Assuming the panel has a diode to prevent energy from flowing through it from the battery when there’s no sunlight. This is fairly common but not very efficient. [Debasish Dutta] has built a charge controller that addresses the inefficiencies of such a system though, and was able to implement maximum power point tracking using an Arduino.

Maximum power point tracking (MPPT) is a method that uses PWM and a special DC-DC converter to match the impedance of the solar panel to the battery. This means that more energy can be harvested from the panel than would otherwise be available. The circuit is placed in between the panel and the battery and regulates the output voltage of the panel so it matches the voltage on the battery more closely. [Debasish] reports that an efficiency gain of 30-40% can be made with this particular design.

This device has a few bells and whistles as well, including the ability to log data over WiFi, an LCD display to report the status of the panel, battery, and controller, and can charge USB devices. This would be a great addition to any solar installation, especially if you’ve built one into your truck.

via Hackaday


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Do you want to make your home  smart? Energy Monitor Shield is the beginning for your IoT application with Arduino.

Energy Monitor Shield6

Energy Monitor Shield is an Arduino-compatible expansion card designed for building energy monitoring system with LCD screen and an interface for connecting the wireless transceiver nRF24L01 +.

Features
  • Connect up to three sensors AC (30-100A).
  • Support for LCD Screen Nokia LCD5110
  • Turn off the LCD backlight with a jumper
  • Two buttons to control (operate one analog pin)
  • Interface to connect the transceiver to 2.4G nRF24L01 +
  • GROVE-compatible connector: I2C
  • Fully compatible with Ethernet Shield

Energy Monitor Shield — Monitoring System with Nokia LCD Screen


9 Comments  →
   by Dost Muhammad Shah    9 Comments  →

In the previous post I explained how to make a connection and send data via TCP connection on SIM900 and similar modems. This post is going to be about FTP connection. FTP stands for “file transfer protocol.” FTP powers one of the fundamental Internet functions and is the prescribed method for the transfer of files between computers. It is also the easiest and most secure way to exchange files over the Internet.

Without going into much details I would show the related AT commands and brief description. Later I would include sample code for FTP upload/download using arduino and SIM900

AT command Response Description
AT+SAPBR OK Configures GPRS profile.
AT+FTPCID=1 OK Selects profile 1 for FTP.
AT+FTPSERV=”****” OK Sets FTP server domain name or IP address. **** is the domain name or the IP.
AT+FTPPORT=*** OK Sets FTP server port. *** is the port.
AT+FTPUN=”***” OK Sets user name for FTP server access. *** is the user name.
AT+FTPPW=”***” OK Sets password for FTP server access. *** is the password.
AT+FTPPUTNAME=”****” OK Sets destiny name for the file.*** is the name of the file.
AT+FTPPUTPATH=”****” OK Sets destiny file path. *** is the path of the file.
AT+FTPPUT OK Use to put a file into the FTP server.
AT+FTPGETNAME=”****” OK Sets origin name for the file.*** is the name of the file.
AT+FTPGETPATH=”****” OK Sets origin file path. *** is the path of the file.
AT+FTPGET Use to get a file into the FTP server.

Make sure you have a server and note the ftp port, we would consider using the default port 21. Switch on your modem and make sure pin code is disabled or properly entered and that GPRS connection is available.

  1. Configure GPRS by sending AT+SAPBR=3,1,”Contype”,”GPRS”r  .
  2. Set APN by sending   AT+SAPBR=3,1,”APN”,”your apn”r  .replace your apn with APN for your network.
  3. Now set the username and password for the apn (replace username and password with correct values )
    AT+SAPBR=3,1,”USER”,”username”r  .
    AT+SAPBR=3,1,”PASS”,”password”r
  4. Connect to GPRS connection by sending AT+SAPBR=1,1r, when connected Modem will respond with OK
  5. Now select profile 1 for FTP by sending AT+FTPCID=1r
  6. Now set FTP server domain or ip using the command AT+FTPSERV=ftp.yourserver.comr
  7. Set FTP port by AT+FTPPORT=21r
  8. Now send FTP credentials using AT+FTPUN=user_namer and AT+FTPPW=”password”r
  9. To get a file from FTP send AT+FTPGETNAME=file_namer
  10.  Now set the path of the file AT+FTPGETPATH=/path/r
  11. Now send AT+FTPGET=1r and wait for response from server, which starts with +FTPGET:1,1
  12. To upload a file to FTP server send AT+FTPPUTNAME=file_namer
  13. Now set path AT+FTPPUTPATH=/pathr
  14. Now send AT+FTPPUT=1 and wait for +FTPPUT:1,1 after which you need to send the content of file to be uploaded.

int8_t answer;
int onModulePin = 2;
char aux_str[30];

char incoming_data[120];

char test_str[ ]= "0000000011111111222222223333333344444444555555556666666677777777000000001111111122222222333333334444";

int data_size, aux;


void setup(){

    pinMode(onModulePin, OUTPUT);
    Serial.begin(115200);


    Serial.println("Starting...");
    power_on();

    delay(5000);

    Serial.println("Connecting to the network...");

    while( (sendATcommand("AT+CREG?", "+CREG: 0,1", 500)
            || sendATcommand("AT+CREG?", "+CREG: 0,5", 500)) == 0 );

    configure_FTP();

    uploadFTP();

    downloadFTP();

    Serial.print("Incoming data: ");
    Serial.println(incoming_data);
}


void loop(){

}


void configure_FTP(){

    sendATcommand("AT+SAPBR=3,1,"Contype","GPRS"", "OK", 2000);
    sendATcommand("AT+SAPBR=3,1,"APN","APN"", "OK", 2000);
    sendATcommand("AT+SAPBR=3,1,"USER","user_name"", "OK", 2000);
    sendATcommand("AT+SAPBR=3,1,"PWD","password"", "OK", 2000);

    while (sendATcommand("AT+SAPBR=1,1", "OK", 20000) != 1);
    sendATcommand("AT+FTPCID=1", "OK", 2000);
    sendATcommand("AT+FTPSERV="ftp.yourserver.com"", "OK", 2000);
    sendATcommand("AT+FTPPORT=21", "OK", 2000);
    sendATcommand("AT+FTPUN="user_name"", "OK", 2000);
    sendATcommand("AT+FTPPW="password"", "OK", 2000);

}


void uploadFTP(){

    sendATcommand("AT+FTPPUTNAME="file_name"", "OK", 2000);
    sendATcommand("AT+FTPPUTPATH="/path"", "OK", 2000);
    if (sendATcommand("AT+FTPPUT=1", "+FTPPUT:1,1,", 30000) == 1)
    {
        data_size = 0;
        while(Serial.available()==0);
        aux = Serial.read();
        do{
            data_size *= 10;
            data_size += (aux-0x30);
            while(Serial.available()==0);
            aux = Serial.read();
        }
        while(aux != 0x0D);

        if (data_size >= 100)
        {
            if (sendATcommand("AT+FTPPUT=2,100", "+FTPPUT:2,100", 30000) == 1)
            {
                Serial.println(sendATcommand(test_str, "+FTPPUT:1,1", 30000), DEC);
                Serial.println(sendATcommand("AT+FTPPUT=2,0", "+FTPPUT:1,0", 30000), DEC);
                Serial.println("Upload done!!");
            }
            else
            {
                sendATcommand("AT+FTPPUT=2,0", "OK", 30000);
            }
        }
        else
        {
            sendATcommand("AT+FTPPUT=2,0", "OK", 30000);
        }
    }
    else
    {
        Serial.println("Error openning the FTP session");
    }
}

void downloadFTP(){

    int x = 0;

    sendATcommand("AT+FTPGETNAME="file_name"", "OK", 2000);
    sendATcommand("AT+FTPGETPATH="/path"", "OK", 2000);
    if (sendATcommand("AT+FTPGET=1 ", "+FTPGET:1,1", 30000) == 1)
    {
        do{
            if (sendATcommand2("AT+FTPGET=2,50", "+FTPGET:2,", "+FTPGET:1,", 30000) == 1)
            {
                data_size = 0;
                while(Serial.available()==0);
                aux = Serial.read();
                do{
                    data_size *= 10;
                    data_size += (aux-0x30);
                    while(Serial.available()==0);
                    aux = Serial.read();
                }while(aux != 0x0D);

                Serial.print("Data received: ");
                Serial.println(data_size);

                if (data_size > 0)
                {
                    while(Serial.available() < data_size);
                    Serial.read();

                    for (int y = 0; y < data_size; y++)
                    {
                        incoming_data[x] = Serial.read();
                        x++;
                    }
                    incoming_data[x] = '';
                }
                else
                {
                    Serial.println("Download finished");
                }
            }
            else if (answer == 2)
            {
                Serial.println("Error from FTP");
            }
            else
            {
                Serial.println("Error getting the file");
                data_size = 0;
            }
        }while (data_size > 0);
    }
    else
    {
        Serial.println("Error openning the FTP session");
    }
}




void power_on(){

    uint8_t answer=0;

    // checks if the module is started
    answer = sendATcommand("AT", "OK", 2000);
    if (answer == 0)
    {
        digitalWrite(onModulePin,HIGH);
        delay(3000);
        digitalWrite(onModulePin,LOW);

        while(answer == 0){     // Send AT every two seconds and wait for the answer
            answer = sendATcommand("AT", "OK", 2000);
        }
    }
}


int8_t sendATcommand(char* ATcommand, char* expected_answer, unsigned int timeout){

    uint8_t x=0,  answer=0;
    char response[100];
    unsigned long previous;

    memset(response, '', 100);    // Initialize the string

    delay(100);

    while( Serial.available() > 0) Serial.read();    // Clean the input buffer

    Serial.println(ATcommand);    // Send the AT command


        x = 0;
    previous = millis();

    // this loop waits for the answer
    do{
        if(Serial.available() != 0){
            // if there are data in the UART input buffer, reads it and checks for the asnwer
            response[x] = Serial.read();
            //Serial.print(response[x]);
            x++;
            // check if the desired answer  is in the response of the module
            if (strstr(response, expected_answer) != NULL)
            {
                answer = 1;
            }
        }
    }
    // Waits for the asnwer with time out
    while((answer == 0) && ((millis() - previous) < timeout));

        return answer;
}

int8_t sendATcommand2(char* ATcommand, char* expected_answer1,
            char* expected_answer2, unsigned int timeout){

    uint8_t x=0,  answer=0;
    char response[100];
    unsigned long previous;

    memset(response, '', 100);    // Initialize the string

    delay(100);

    while( Serial.available() > 0) Serial.read();    // Clean the input buffer

    Serial.println(ATcommand);    // Send the AT command


        x = 0;
    previous = millis();

    // this loop waits for the answer
    do{
        // if there are data in the UART input buffer, reads it and checks for the asnwer
        if(Serial.available() != 0){
            response[x] = Serial.read();
            x++;
            // check if the desired answer 1 is in the response of the module
            if (strstr(response, expected_answer1) != NULL)
            {
                answer = 1;
            }
            // check if the desired answer 2 is in the response of the module
            if (strstr(response, expected_answer2) != NULL)
            {
                answer = 2;
            }
        }
        // Waits for the asnwer with time out
    }while((answer == 0) && ((millis() - previous) < timeout));

        return answer;
}


 


99 Comments  →
   by Dost Muhammad Shah    99 Comments  →

GSM/GPRS modems are getting very common these days, as prices are getting cheaper and cheaper. Apart from providing SMS and call functions to my projects I also wanted to communicate via TCP.

Although there are many documents and blog posts to help but I have always found that they either are answers to specific problem faced by someone or not providing complete details.  In this post I would first explain the AT commands used in brief. You may connect your SIM900 to your computer via a serial/usb and test these commands. In the later part of this post I would include arduino example code.

AT commands for TCP/UDP Connection with example response and a brief description are given in the table below. Refer to the AT commands manual of your modem for details

AT command Response Description
AT  OK test command. reply is OK
AT+CGATT?  +CGATT:n checks if GPRS is attached? n=1 if attached
AT+CIPMUX=n  OK use n as 0 for single connection
or use 1 for multiple connections
AT+CSTT=”apn”,”username”,”pass” OK Sets APN, user name and password
AT+CIICR  OK Brings up wireless connection
AT+CIFSR  ip address Get local IP address if connected
AT+CIPSTART=“TYPE” , “domain”, “port”  Connected Establishes a connection with a server. Type can be UDP or TCP
AT+CIPSEND  > Sends data when the a connection is established.
AT+CIPCLOSE  OK Closes the connection
AT+CIPSHUT  SHUT OK resets IP session if any

how to make a connection:

  1. Send ATr and wait for a response from the modem. You should recieve OK
    if everything is set.
  2. Make sure that the Modem has registered to network and that PIN code is disabled on the SIM. Send AT+CGATT?r to check if GPRS is attached or not.  +CGATT: 1 indicates that GPRS is attached.
  3. Send AT+CIPSHUTr . Although its optional this will be helpful as it resets IP session if any. you will get a response SHUT OK .
  4. Send AT+CIPMUX=0 to set a single connection mode, response would be OK
  5. Now set APN settings by AT+CSTT= “apn ”, “username”, “password”r . replace apn, username and password to match APN (Access Point Name) ,username and password for your service provider.
  6. Now send AT+CIICRr , this will bring up the wireless connection. OK is received on successful connection
  7. Send AT+CIFSRr , this will reply with the IP address the modem has been assigned.
  8. Send AT+CIPSTART=”TCP”,”server domain name or ip”,”port”r, replace the domain name/ip and port with appropriate values, on connection modem will reply with CONNECT OK
  9. Now you can send your data using AT+CIPSENDr  AT command. modem will respond with > indicating it is ready to receive data to be sent. Type in your data.
  10. Now the modem is waiting for the ASCII 26  that is control+z on keyboard. Depending on the terminal software used you can either press control and Z together on keyboard or send hex value 0x1A. The modem will then send the response from server.
  11. Now send AT+CIPSHUT to shut down the connection. Modem will reply with SHUT OK 
  12. cheers 🙂

ARDUINO CODE :

Below is example code for single and multiple connection using arduino and sim900

int8_t answer;
int onModulePin= 2;
char aux_str[50];
char ip_data[40]="Test string from GPRS shieldrn";
void setup(){
    pinMode(onModulePin, OUTPUT);
    Serial.begin(115200);
    Serial.println("Starting...");
    power_on();
    delay(3000);
    // sets the PIN code
    sendATcommand2("AT+CPIN=****", "OK", "ERROR", 2000);
    delay(3000);
    Serial.println("Connecting to the network...");
    while( sendATcommand2("AT+CREG?", "+CREG: 0,1", "+CREG: 0,5", 1000)== 0 );
}
void loop(){
    // Selects Single-connection mode
    if (sendATcommand2("AT+CIPMUX=0", "OK", "ERROR", 1000) == 1)
    {
        // Waits for status IP INITIAL
        while(sendATcommand2("AT+CIPSTATUS", "INITIAL", "", 500)  == 0 );
        delay(5000);

        // Sets the APN, user name and password
        if (sendATcommand2("AT+CSTT="APN","user_name","password"", "OK",  "ERROR", 30000) == 1)
        {
            // Waits for status IP START
            while(sendATcommand2("AT+CIPSTATUS", "START", "", 500)  == 0 );
            delay(5000);

            // Brings Up Wireless Connection
            if (sendATcommand2("AT+CIICR", "OK", "ERROR", 30000) == 1)
            {
                // Waits for status IP GPRSACT
                while(sendATcommand2("AT+CIPSTATUS", "GPRSACT", "", 500)  == 0 );
                delay(5000);

                // Gets Local IP Address
                if (sendATcommand2("AT+CIFSR", ".", "ERROR", 10000) == 1)
                {
                    // Waits for status IP STATUS
                    while(sendATcommand2("AT+CIPSTATUS", "IP STATUS", "", 500)  == 0 );
                    delay(5000);
                    Serial.println("Openning TCP");

                    // Opens a TCP socket
                    if (sendATcommand2("AT+CIPSTART="TCP","IP_address","port"",
                            "CONNECT OK", "CONNECT FAIL", 30000) == 1)
                    {
                        Serial.println("Connected");

                        // Sends some data to the TCP socket
                        sprintf(aux_str,"AT+CIPSEND=%d", strlen(ip_data));
                        if (sendATcommand2(aux_str, ">", "ERROR", 10000) == 1)
                        {
                            sendATcommand2(ip_data, "SEND OK", "ERROR", 10000);
                        }

                        // Closes the socket
                        sendATcommand2("AT+CIPCLOSE", "CLOSE OK", "ERROR", 10000);
                    }
                    else
                    {
                        Serial.println("Error openning the connection");
                    }
                }
                else
                {
                    Serial.println("Error getting the IP address");
                }
            }
            else
            {
                Serial.println("Error bring up wireless connection");
            }
        }
        else
        {
            Serial.println("Error setting the APN");
        }
    }
    else
    {
        Serial.println("Error setting the single connection");
    }

    sendATcommand2("AT+CIPSHUT", "OK", "ERROR", 10000);
    delay(10000);
}

void power_on(){

    uint8_t answer=0;

    // checks if the module is started
    answer = sendATcommand2("AT", "OK", "OK", 2000);
    if (answer == 0)
    {
        // power on pulse
        digitalWrite(onModulePin,HIGH);
        delay(3000);
        digitalWrite(onModulePin,LOW);

        // waits for an answer from the module
        while(answer == 0){     // Send AT every two seconds and wait for the answer
            answer = sendATcommand2("AT", "OK", "OK", 2000);
        }
    }

}

int8_t sendATcommand2(char* ATcommand, char* expected_answer1,
        char* expected_answer2, unsigned int timeout){

    uint8_t x=0,  answer=0;
    char response[100];
    unsigned long previous;

    memset(response, '', 100);    // Initialize the string

    delay(100);

    while( Serial.available() > 0) Serial.read();    // Clean the input buffer

    Serial.println(ATcommand);    // Send the AT command

    x = 0;
    previous = millis();

    // this loop waits for the answer
    do{
        // if there are data in the UART input buffer, reads it and checks for the asnwer
        if(Serial.available() != 0){
            response[x] = Serial.read();
            x++;
            // check if the desired answer 1  is in the response of the module
            if (strstr(response, expected_answer1) != NULL)
            {
                answer = 1;
            }
            // check if the desired answer 2 is in the response of the module
            else if (strstr(response, expected_answer2) != NULL)
            {
                answer = 2;
            }
        }
    }
    // Waits for the asnwer with time out
    while((answer == 0) && ((millis() - previous) < timeout));

    return answer;
}
int8_t answer;
int onModulePin= 2;
char aux_str[50];

char ip_data[40]="Test string from GPRS shieldrn";

void setup(){

    pinMode(onModulePin, OUTPUT);
    Serial.begin(115200);

    Serial.println("Starting...");
    power_on();

    delay(3000);

    // sets the PIN code
    sendATcommand2("AT+CPIN=****", "OK", "ERROR", 2000);

    delay(3000);

    Serial.println("Connecting to the network...");

    while( sendATcommand2("AT+CREG?", "+CREG: 0,1", "+CREG: 0,5", 1000) == 0 );

}


void loop(){


    // Selects Multi-connection mode
    if (sendATcommand2("AT+CIPMUX=1", "OK", "ERROR", 1000) == 1)
    {
        // Waits for status IP INITIAL
        while(sendATcommand2("AT+CIPSTATUS", "INITIAL", "", 500)  == 0 );
        delay(5000);

        // Sets the APN, user name and password
        if (sendATcommand2("AT+CSTT="APN","user_name","password"", "OK",  "ERROR", 30000) == 1)
        {
            // Waits for status IP START
            while(sendATcommand2("AT+CIPSTATUS", "START", "", 500)  == 0 );
            delay(5000);

            // Brings Up Wireless Connection
            if (sendATcommand2("AT+CIICR", "OK", "ERROR", 30000) == 1)
            {
                // Waits for status IP GPRSACT
                while(sendATcommand2("AT+CIPSTATUS", "GPRSACT", "", 500)  == 0 );
                delay(5000);

                // Gets Local IP Address
                if (sendATcommand2("AT+CIFSR", ".", "ERROR", 10000) == 1)
                {
                    // Waits for status IP STATUS
                    while(sendATcommand2("AT+CIPSTATUS", "IP STATUS", "", 500)  == 0 );
                    delay(5000);
                    Serial.println("Openning TCP");

                    // Opens a TCP socket with connection 1
                    if (sendATcommand2("AT+CIPSTART=1,"TCP","IP_address","port"",
                                    "CONNECT OK", "CONNECT FAIL", 30000) == 1)
                    {
                        Serial.println("Connected");

                        // Sends some data to the TCP socket
                        sprintf(aux_str,"AT+CIPSEND=1,%d", strlen(ip_data));
                        if (sendATcommand2(aux_str, ">", "ERROR", 10000) == 1)
                        {
                            delay(500);
                            sendATcommand2(ip_data, "SEND OK", "ERROR", 10000);
                        }

                        // Closes the socket
                        sendATcommand2("AT+CIPCLOSE=1", "CLOSE OK", "ERROR", 10000);
                    }
                    else
                    {
                        Serial.println("Error openning the connection 1");
                    }

                }
                else
                {
                    Serial.println("Error getting the IP address");
                }
            }
            else
            {
                Serial.println("Error bring up wireless connection");
            }
        }
        else
        {
            Serial.println("Error setting the APN");
        }
    }
    else
    {
        Serial.println("Error setting the multi-connection");
    }

    sendATcommand2("AT+CIPSHUT", "OK", "ERROR", 10000);
    delay(10000);
}

void power_on(){

    uint8_t answer=0;

    // checks if the module is started
    answer = sendATcommand2("AT", "OK", "OK", 2000);
    if (answer == 0)
    {
        // power on pulse
        digitalWrite(onModulePin,HIGH);
        delay(3000);
        digitalWrite(onModulePin,LOW);

        // waits for an answer from the module
        while(answer == 0){     // Send AT every two seconds and wait for the answer
            answer = sendATcommand2("AT", "OK", "OK", 2000);
        }
    }

}

int8_t sendATcommand2(char* ATcommand, char* expected_answer1,
        char* expected_answer2, unsigned int timeout){

    uint8_t x=0,  answer=0;
    char response[100];
    unsigned long previous;

    memset(response, '', 100);    // Initialize the string

    delay(100);

    while( Serial.available() > 0) Serial.read();    // Clean the input buffer

    Serial.println(ATcommand);    // Send the AT command

    x = 0;
    previous = millis();

    // this loop waits for the answer
    do{
        // if there are data in the UART input buffer, reads it and checks for the asnwer
        if(Serial.available() != 0){
            response[x] = Serial.read();
            x++;
            // check if the desired answer 1  is in the response of the module
            if (strstr(response, expected_answer1) != NULL)
            {
                answer = 1;
            }
            // check if the desired answer 2 is in the response of the module
            else if (strstr(response, expected_answer2) != NULL)
            {
                answer = 2;
            }
        }
    }
    // Waits for the asnwer with time out
    while((answer == 0) && ((millis() - previous) < timeout));

    return answer;
}