Temperature.cpp

00001 #include "mbed.h"
00002 #include "Temperature.h"
00003 
00004 //DigitalOut sensor_en ( PC8 ); // GPIO pin PC8 connected to the sensor
00005     
00006 //I2C i2c(PD6, PD7);  //SDA pin connected to PD6, SCL pin cpnnected to PD7
00007 Labb2::Labb2(char Address): sensor_en (PC8), i2c( PD6, PD7){
00008 cAddress=Address;}
00009 float Labb2::get_temp()
00010 {
00011     
00012     //const int address = 0x80; // address too the thermometer
00013     
00014     char command[1]; // store commands
00015     command[0] = 0xF3; // measure temperature
00016     
00017     char data[2]; // store data
00018     
00019     float temp; // store our temperature
00020     
00021     if(true) {
00022 
00023         i2c.write(cAddress, command, 1);                 //Initialize SI7021
00024 
00025         wait(0.5);
00026 
00027         i2c.read(cAddress, data, 2);                        //Read data
00028 
00029         temp = (uint16_t)((data[0] << 8)|data[1]);    //convert two chars to int
00030 
00031         temp = ((175.72*temp)/65536)-46.85;            //16-bit word return to celsius 
00032                 
00033         wait(2); 
00034         return temp;       
00035     }   
00036 }
00037 
00038 void Labb2::power_sensor(int i)   //Starts sensor with 1 and stops with 0
00039 {
00040     if(i == 1)
00041     {
00042         sensor_en = 1; // enable power supply
00043         printf("Sensor is on\n");
00044         wait (0.1) ; // give the sensor some time to start up
00045     }
00046     else
00047     {
00048         sensor_en = 0; // disable power supply
00049         printf("Sensor is off\n");
00050     }
00051 }
00052 
00053 
00054 float Labb2::c_to_f(float celsius)
00055 {
00056         float fahrenheit;
00057         fahrenheit = (1.8 * celsius + 32);    //converts temperature to Fahrenheit
00058         return fahrenheit;
00059 }