main.cpp

00001 #include "mbed.h"
00002 
00003 /***********************************************************************
00004 * Read temperature by using DS1631
00005 *
00006 * Normal I2C-protocol (start,write,..,stop) does NOT work
00007 * It has to be used 
00008 *   i2c.write(address,data,length,repeat) 
00009 * which includes start and stop and a special addressing function
00010 ************************************************************************/
00011 DigitalOut myled(LED2);
00012 DigitalIn button(USER_BUTTON);
00013 I2C i2c (PB_9,PB_8);           // sda, scl
00014 
00015 int main() {
00016     int data;
00017     uint16_t cr1;
00018     int ack;
00019     char data_write[2];
00020     char data_read[2];
00021     //cr1 = I2C1->CR1;
00022     //I2C1->CR2 = 0x0002;
00023      
00024     data_write[0] = 0xEE;
00025     ack = i2c.write(0x90, data_write, 1, 0);       
00026     data_write[0] = 0xAC;               // writes the 1-byte configuration register
00027     data_write[1] = 0x0F;               // 1shot;12bit;pol=1
00028     ack = i2c.write(0x90, data_write, 2, 0);       
00029 
00030     while(1) {
00031         while (button);                 // start measurement by user_button
00032  
00033         data_write[0] = 0x51;           // Initiates temperature conversions
00034         ack = i2c.write(0x90, data_write, 1, 0);       
00035         //printf("%d\n",ack);
00036         wait_ms(1000);
00037          
00038         data_write[0] = 0xAA;           // Reads last converted temperature value from the 2-byte temperature register
00039         ack = i2c.write(0x90, data_write, 1, 1);     
00040         i2c.read(0x90, data_read, 2, 0); 
00041          
00042         data=data_read[0]*100;
00043         data=data+(((data_read[1] >> 4 )* 50)/8);
00044         printf("%d\n",data);
00045         //wait_ms(1000);               
00046     }
00047 }