Serial_Comm_Nano.ino.c

/*
* Serial_Comm_Nano.ino
*
*/
///@file Serial_Comm_Nano.ino
///@brief AT-command compatible cellular/GPRS/IP modem initialization & communication for SIM900D -> Arduino -> ArduCopter
///@author Robert Haddad
///@date 25-10-2014
#include <SoftwareSerial.h> // Include SoftwareSerial Library
//Serial Communication Ports
#define rxPin 4 // TX from GSM Modem to RX on Arduino
#define txPin 5 // RX from GSM Modem to TX on Arduino
#define LED 12 // All Good LED Turns green when data is being sent over UDP Connection
#define ERR 11 // Error LED Turns Red when error is encountered, turns off if all is okay
#define powerKey 3 // Set PWRKEY pin
#define resetPin 2 // Set reset pin
boolean isReady = false; // GSM modem is Ready to receive AT Commands flag
int count = 0; // Counter for instances of an error (For monitor/debug only);
String checker = "";
// set up a new serial port for GSM Module
SoftwareSerial mySerial = SoftwareSerial(rxPin, txPin); // Initialize mySerial SoftwareSerial
// Setup procedure
void setup()
{
    pinMode(rxPin, INPUT); // Set pin mode to input for Software serial RX Pin
    pinMode(txPin, OUTPUT); // Set pin mode to output for Software serial TX Pin
    pinMode(LED, OUTPUT); // All Good LED
    pinMode(ERR, OUTPUT); // Warning LED
    digitalWrite(LED,LOW); // Set All Good LED to Off
    digitalWrite(ERR,LOW); // Set Warning LED to Off
    digitalWrite(resetPin, HIGH); // Set reset pin to high

    // Set Data Rate for Serial Ports
    mySerial.begin(57600); // Start GSM Module Serial Communication @ 57,600 Baud Rate
    pinMode(resetPin, OUTPUT); // Set reset pin to output
    // Wait 3 Seconds for power on (Add Auto on feature through GSM module power button pin
    startUPWait();

    // Initializing GSM Module
    mySerial.print("AT\r");
    while(!isReady){
        if(mySerial.available()){
            String b=mySerial.readString();
            if(b.indexOf("+CREG: 1") > 0 || b.indexOf("+CREG: 2") > 0){
                isReady = true;
                //while(!sendATCommand("AT+IPR=57600","OK",100)); // Uncomment to set Modem Baudrate
                //while(!sendATCommand("AT&W","OK",100)); // Uncomment to write settings to non-volatile memory
                while(!sendATCommand("AT V1 E1 X1 S0=0","OK",100)); // Set error response and do not pickup on ring
                while(!sendATCommand("AT+CREG=2","OK",100)); // Set various notice messages and parameters
                while(!sendATCommand("AT+CMEE=2","OK",100));
                while(!sendATCommand("AT+CR=1","OK",100));
                while(!sendATCommand("AT+CRC=1","OK",100));
                while(!sendATCommand("AT+CSNS=4","OK",100));
                while(!sendATCommand("AT+CSMINS=1","OK",100));
                while(!sendATCommand("AT+CSCLK=0","OK",100));
                while(!sendATCommand("AT+CIURC=1","OK",100));
                while(!sendATCommand("AT+CGEREP=2","OK",100));
                while(!sendATCommand("AT+CIPMUX=0","OK",100)); // Single channel communication (ie only one socket can be opened)
                while(!sendATCommand("AT+CIPMODE=1","OK",100)); // Transparent bridge mode
                while(!sendATCommand("AT+CIPCCFG=8,10,400,0","OK",100)); // GPRS params
                mySerial.print("AT+CMUX=0,0,4,32768,10,3,30,10,2\r"); // GPRS/IP params
                delay(2000);
                while(!sendATCommand("AT+CGATT?","OK",1000)); // Make sure GPRS is Attached
                while(!sendATCommand("AT+CSTT= \"zain\",\"\",\"\"","OK",1000)); // AT+CSTT="APN","username","password" - login to service provider/carrier
                while(!sendATCommand("AT+CIICR","OK",1000)); // Connect!
                while(!sendATCommand("AT+CIFSR",".",100)); // Get IP address (for info only);
                while(!sendATCommand("AT+CLPORT=\"UDP\",8888","OK",100)); // Prep UDP Port 8888
                while(!sendATCommand("AT+CIPSTART=\"UDP\",\"drone.dyndns.biz\",8888","OK",1000)); // AT+CIPSTART="protocol","ip address or domain","port #"
                Serial.begin(57600); // Start Serial port for communication with Ardupilot
                digitalWrite(LED,HIGH); // Turn on All Good LED
                digitalWrite(ERR,LOW); // Turn off Warning LED
                delay(1000);
                digitalWrite(LED,LOW);
            } else {
                digitalWrite(ERR,HIGH); // Turn on Warning LED
                digitalWrite(LED,LOW); // Turn off All Good LED
            }
        }
    }
}
                                                                            // AT Command Sender
boolean sendATCommand(String input, String output, int wait){ // AT Command, Expected Result, Delay before issue command
    boolean resp = false;
    mySerial.print(input + "\r"); // Send input command to modem
    delay(wait); // Delay function time "wait" variable
    while(!resp){
        if(mySerial.available()){ // Check if response is available
            String b=mySerial.readString(); // Store response string in "b"
            mySerial.read(); // Clear buffer again
            if(b.indexOf(output) > 0){ // True if expected result is returned
                resp = true;
                count = 0;
                digitalWrite(LED,HIGH); // Green LED ON
                digitalWrite(ERR,LOW); // Warning LED OFF
                digitalWrite(LED,LOW); // Green LED OFF
                return resp;
            } else if(b.indexOf("DEACT") > 0 || b.indexOf("NORMAL POWER DOWN") > 0){ // Check if lost connection or modem power down
                if(powerUpOrDown()){ // Reset comm hardware
                    digitalWrite(resetPin,LOW); // Restart Modem
                }
            } else {
                digitalWrite(ERR,HIGH); // Warning LED ON
                count++;
                return resp;
            }
        }
    }
}
//Start Up Wait Period with LEDs
void startUPWait(){
    digitalWrite(LED,HIGH);
    digitalWrite(ERR,LOW);
    delay(500);
    digitalWrite(LED,LOW);
    digitalWrite(ERR,HIGH);
    delay(500);
    digitalWrite(LED,HIGH);
    digitalWrite(ERR,LOW);
    delay(500);
    digitalWrite(LED,LOW);
    digitalWrite(ERR,HIGH);
    delay(500);
    digitalWrite(LED,HIGH);
    digitalWrite(ERR,HIGH);
    delay(1000);
    digitalWrite(LED,LOW);
    digitalWrite(ERR,LOW);
}
// Main Loop
void loop(){
    digitalWrite(LED,HIGH); // Keep Green LED ON while connected
    // Relay All GSM Module communication to Autopilot
    if(mySerial.available()){
        char b=mySerial.read();
        Serial.write(b);
        // Check For Disconnection
        checker += b;
        if(checker.indexOf("\n") > 0 || checker.indexOf("\r") > 0){ // Check for new line
            if(checker.indexOf("DEACT") > 0 || checker.indexOf("NORMA") > 0){ // Check for lost connection or Modem power down
                digitalWrite(LED,LOW); // Green LED OFF
                digitalWrite(ERR,HIGH); // Warning LED ON
                if(powerUpOrDown()){ // Reset Comm Hardware
                    digitalWrite(resetPin,LOW); // Reset Modem
                }
            }
            checker = "";
        }
        digitalWrite(ERR,HIGH); // Flash Warning LED on data send/receive
        digitalWrite(ERR,LOW);
        //Serial.print(b);
    }

    // Relay all Autopilot communication to GSM module and USB (USB for monitor/debug only)
    if(Serial.available()){
        char c=Serial.read();
        mySerial.write(c);
        digitalWrite(ERR,HIGH); // Flash Warning LED on data send/receive
        digitalWrite(ERR,LOW);
    }
}
boolean powerUpOrDown() // Cycle power on Modem
{
    boolean powered = false;
    pinMode(powerKey, OUTPUT);
    digitalWrite(powerKey,LOW);
    delay(1000);
    digitalWrite(powerKey,HIGH);
    delay(2000);
    digitalWrite(powerKey,LOW);
    delay(3000);
    powered = true;
    return powered;
}