File content as of revision 0:d08b5dcb3f52:

#include "mbed.h"
DigitalOut led1(p24);
DigitalOut led2(p23);
DigitalOut led3(p22);
DigitalOut led4(p21);
AnalogIn photo(p15);
AnalogIn LM19(p18);
Serial pc(USBTX, USBRX);

struct NMEA{
    char header[5];
    char buffer[100];
    char checksum[2];
};

NMEA data;
Timer t;
    
int main() {
    t.start(); 
    while(1) {
        float light = photo.read();
        float temp = LM19.read();
        float tempC = (1.8663 - 3.3*temp)/0.01169;
        //print NMEA string
         pc.printf("$TTMPL  %f, %f, %f, %f; \r\n", t.read(), temp, tempC, light);
        if (tempC < 20 & light > 1.75) {
        led1 = 1;
        led2 = 0;
        led3 = 0;
        led4 = 0;
        // 3.3 print out 
        pc.printf("$TTMPL  %f, %f, %f, Cold, %f, Day; \r\n", t.read(), temp, tempC, light);
        } 
        if (tempC < 20 & light < 1.75) {
        led1 = 0;
        led2 = 1;
        led3 = 0;
        led4 = 0;
         // 3.3 print out 
        pc.printf("$TTMPL  %f, %f, %f, Cold, %f, Night; \r\n", t.read(), temp, tempC, light);
        }
        if (tempC > 20 & light > 1.75) {
        led1 = 0;
        led2 = 0;
        led3 = 1;
        led4 = 0;
         // 3.3 print out 
         pc.printf("$TTMPL  %f, %f, %f, Hot, %f, Day; \r\n", t.read(), temp, tempC, light);
        }
        if (tempC > 20 & light < 1.75) {
        led1 = 0;
        led2 = 0;
        led3 = 0;
        led4 = 1;
         // 3.3 print out 
         pc.printf("$TTMPL  %f, %f, %f, Hot, %f, Night; \r\n", t.read(), temp, tempC, light);
        }
        wait(5);
            
            //clean serial ports 
            while(pc.readable()){
            pc.getc();
            
            }
        }
        }