File content as of revision 1:b672c24629d5:

#include "mbed.h"
#include "MPL3115A2.h"
#include "string.h"
MPL3115A2 pressure_sensor(PB_7,PB_6,0x60);
Serial pc(SERIAL_TX, SERIAL_RX, 115200);
Serial device(PA_9, PA_10, 115200);  // tx, rx
DigitalOut myled(LED1);

/*  Checks to see if the xDot has a buffered message OK to 
    confirm that operation has succeeded
*/
int confirmOK() { 
    char buf[20];
    int i = 0; 
    while (device.readable()) { 
        buf[i] = device.getc();
        if (i > 20) { 
            return 0;
        }
        i++;
    }
    return strncmp("OK",buf,2);
}
/*  Sends a message to the xDot
    Messages are expected to end in \n so that an OK confirmation will be 
    recieved
*/
int sendAtMessage(char * message) { 
    while (*message) { 
        device.putc(*message);
        message++;
    }
    return confirmOK();
}

/*
Send a message to the xDot without checking for acknowledge
*/
void sendAtMessageNACK(char * message) { 
    while (*message) { 
        device.putc(*message);
        message++;
    }
}
int main() {
    
    pc.printf("Starting program\n\r");

    //Try to connect xDot to network
    // Provice network name
    char networkName[] = "AT+NI=1, MTCDT-19400691\n";
    sendAtMessage(networkName);
    //Provide network passphrase
    char networkPassphrase[] = "AT+NK=1,MTCDT-19400691\n";
    sendAtMessage(networkPassphrase);
    //Set the frequency sub band
    char frequencySubBand[] = "AT+FSB=1\n";
    sendAtMessage(frequencySubBand);
    //Join the network
    char joinNetwork[] = "AT+JOIN\n"; // Unable to join network atm.
    if (!sendAtMessage(joinNetwork)) { 
        pc.printf("Error, unable to connect to network");
    }
    wait_ms(500);
    
    //When an s is read from the serial pc,
    // read the current pressure/temperature from the I2C pressure sensor
    // and send it to the MQTT server pivot.iuiot
    
    //Unsure of what size to set Buffer so that it doesn't go over
    //when trying to send a message
    while(1) {
        if (pc.readable()) { 
            if (pc.getc() == 's') { 
                double temp = pressure_sensor.getTemperature();
                char tempBuf[6];
                double pres = pressure_sensor.getPressure();
                char presBuf[7];
                pc.printf("Current temp is %f\n\r",temp);
                pc.printf("Current pres is %f\n\r",pres);
                sprintf(tempBuf, "%2.2f",temp);
                sprintf(presBuf, "%4.1f",pres);
                pc.printf("After convert with sprintf temp = %s\n\r",tempBuf);
                pc.printf("After convert with sprintf pres = %s\n\r",presBuf);
                
            }
        }
    }
    
    /*
    while(1) {
        if(pc.readable()) {
            device.putc(pc.getc());
            myled = !myled;
        }
        if(device.readable()) {
            pc.putc(device.getc());
            myled = !myled;
        }
    }
    */
}