main.cpp

00001 /*********************************
00002 **Read DS1631 Temperature Sensor**
00003 ******Made by Stijn Sontrop*******
00004 **********22 Dec 2010*************
00005 **********************************/
00006 
00007 #include "mbed.h"
00008 #include <TextLCD.h> //Include the TextLCD lib (add this one to your project)
00009 
00010 ///DS1631 Address:
00011 //Formation: 1001 A2 A1 A0 R/W'
00012 //Write: Make R/W' 0
00013 #define DS1631WRITEADDRESS 0x90
00014 //Read: Make R/W' 1
00015 #define DS1631READADDRESS 0x91
00016 
00017 TextLCD lcd(p15, p16, p17, p18, p19, p20); //LCD config rs, e, d4-d7
00018 
00019 I2C i2c(p9, p10); //SDA & SCL from I2C
00020 typedef struct { //Struct to contain read values
00021     char msb;
00022     char lsb;
00023 } temperature;
00024 
00025 temperature readds1631(void) {
00026     temperature readval;
00027     i2c.start();
00028     i2c.write(DS1631WRITEADDRESS);
00029     i2c.write(0xAA); //Read the temperature
00030     i2c.stop();
00031     wait_ms(1);
00032     i2c.start();
00033     i2c.write(DS1631READADDRESS);
00034     readval.msb = i2c.read(1); //Read the MSB (and do an ACK)
00035     readval.lsb = i2c.read(0); //Read the LSB (and don't do an ACK)
00036     i2c.stop();
00037     readval.msb = readval.msb - 2; //Apparently you need to do -2 to get the right value
00038     return readval; //Return the value
00039 }
00040 
00041 int main() {
00042     temperature readval;
00043     i2c.start();
00044     i2c.write(DS1631WRITEADDRESS); //address
00045     i2c.write(0xAC); //config reg
00046     i2c.write(0x02); //config
00047     i2c.stop();
00048     
00049     //Start conversion:
00050     i2c.start();
00051     i2c.write(DS1631WRITEADDRESS);
00052     i2c.write(0x51); //start conversion
00053     i2c.stop();
00054     while(1) {
00055         readval = readds1631(); //Call the readds1631 function
00056         lcd.cls(); //Clear the LCD
00057         lcd.printf("Temp: %d\nLSB:%d", readval.msb, readval.lsb);
00058         wait(0.3); 
00059     }
00060 }