gistfile1.txt

#include "mbed.h"
#include "N5110.h"

#define TMP102_ADD 0X48
#define TMP102_R_ADD 0x91
#define TMP102_W_ADD 0x90

#define TEMP_REG 0x00
#define CONFIG_REG 0x01
#define THIGH_REG 0x02
#define TLOW_REG 0x03

////////////////////////////////////////////////////////////////////////////////////
N5110 lcd(p7,p8,p9,p10,p11,p13,p21);
BusOut leds(LED4,LED3,LED2,LED1);
LocalFileSystem local("local"); // create local filesystem
float getTemperature();
void initTMP102();
void error(int code);
Serial serial(USBTX,USBRX);
void serialISR(); // ISR that is called when serial data is received
void setTime(); // function to set the UNIX time
void writeDataToFile(int data, float temperature, char *date, char *time);
int setTimeFlag = 0; // flag for ISR
char rxString[16]; // buffer to store received string


I2C tmp102(p28,p27); // SDA, SCL

int main()
{
    int counter = 0; // variable to increment
    serial.attach(&serialISR); // attach serial ISR
    char buffer1[30]; // buffer used to store time string
    char buffer2[30]; // buffer used to store time string

    set_time(1420195048); // initialise time to 1st January 1970

    initTMP102();
    lcd.init();
    char buffer[30];

    while(1)
    {
        float temperatureTW = getTemperature();
        sprintf(buffer,"Temp=%4.2f",temperatureTW);
        lcd.printString(buffer,0,3);
//wait(0.2);
        time_t seconds = time(NULL); // get current time
        // format time into a string (time and date)
        strftime(buffer1, 30 , "%X", localtime(&seconds));
        // print over serial
        serial.printf("Time = %s\n",buffer1);
        strftime(buffer2, 30 , "%D", localtime(&seconds));
        // print over serial
        //serial.printf("Time = %s\n",buffer2);
        //wait(1.0); // delay for a second

        if (setTimeFlag) { // if updated time has been sent
            setTimeFlag = 0; // clear flag
            setTime(); // update time
        }

        lcd.printString(buffer1,0,1);
        lcd.printString(buffer2,0,2);

        writeDataToFile(counter, temperatureTW, buffer2, buffer1); // write current value to disk
        counter++; // increment counter
        wait(1.0); // small delay
    }
}




//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void initTMP102()
{
    tmp102.frequency(400000); // set bus speed to 400 kHz
    int ack; // used to store acknowledgement bit
    char data[2]; // array for data
    char reg = CONFIG_REG; // register address
    //////// Read current status of configuration register ///////

    ack = tmp102.write(TMP102_W_ADD,&reg,1); // send the slave write address and the configuration register address
    if (ack)
        error(1); // if we don't receive acknowledgement, flash error message
    ack = tmp102.read(TMP102_R_ADD,data,2); // read default 2 bytes from configuration register and store in buffer
    if (ack)
        error(2); // if we don't receive acknowledgement, flash error message
    ///////// Configure the register //////////
    // set conversion rate to 1 Hz
    data[1] |= (1 << 6); // set bit 6
    data[1] &= ~(1 << 7); // clear bit 7

    //////// Send the configured register to the slave ////////////

    ack = tmp102.write(TMP102_W_ADD,&reg,1); // send the slave write address and the configuration register address
    if (ack)
        error(3); // if we don't receive acknowledgement, flash error message
    ack = tmp102.write(TMP102_W_ADD,data,2); // send 2 data bytes to the configuration register
    if (ack)
        error(4); // if we don't receive acknowledgement, flash error message

}
// hang in infinite loop flashing error code
void error(int code)
{
    while(1) {
        leds = 0;
        wait(0.25);
        leds = code;
        wait(0.25);
    }
}



//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
float getTemperature()
{
    int ack; // used to store acknowledgement bit
    char data[2]; // array for data
    char reg = TEMP_REG; // temperature register address
    ack = tmp102.write(TMP102_W_ADD,&reg,1); // send temperature register address
    if (ack)
        error(5); // if we don't receive acknowledgement, flash error message
    ack = tmp102.read(TMP102_R_ADD,data,2); // read 2 bytes from temperature register and store in array
    if (ack)
        error(6); // if we don't receive acknowledgement, flash error message
    int temperature = (data[0] << 4) | (data[1] >> 4);
    return temperature*0.0625;
}



//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void setTime() {
    // print time for debugging
    serial.printf("set_time - %s",rxString);
    // atoi() converts a string to an integer
    int time = atoi(rxString);
    // update the time
    set_time(time);
}
void serialISR() {
    // when a serial interrupt occurs, read rx string into buffer
    serial.gets(rxString,16);
    // set flag
    setTimeFlag = 1;
}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void writeDataToFile(int data, float temperature, char *date, char *time)
{
    leds = 15; // turn on LEDs for feedback
    FILE *fp = fopen("/local/log.txt", "a"); // open 'log.txt' for appending
    // if the file doesn't exist it is created, if it exists, data is appended to the end
    fprintf(fp, "%s %s, %4.2f", date, time, temperature);
    fclose(fp); // close file
    leds = 0; // turn off LEDs to signify file access has finished
}