Launchpad: tmp102

tmp102.c

#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "driverlib/i2c.h"
#include "utils/uartstdio.h"

#define SLAVE_ADDRESS 0x48        // TMP102 I2C Address (ADDR0 is GND)

void initUART(void)
{
  //enable portA
  SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
  //configure the pin multiplexing
  GPIOPinConfigure(GPIO_PA0_U0RX);
  GPIOPinConfigure(GPIO_PA1_U0TX);
  //configure the type of the pins for uart tx/rx
  GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
  //init the console
  UARTStdioInit(0);
}

int main(void){
  unsigned char tx;
  unsigned char rx[2];
  
  SysCtlClockSet(SYSCTL_SYSDIV_4|SYSCTL_USE_PLL|SYSCTL_XTAL_16MHZ|SYSCTL_OSC_MAIN);
  
  initUART();
  
  SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0);
  SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
  
  // Set up the pins as I2C
  GPIOPinTypeI2CSCL(GPIO_PORTB_BASE, GPIO_PIN_2);
  GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_3);
  
  GPIOPinConfigure(GPIO_PB2_I2C0SCL);
  GPIOPinConfigure(GPIO_PB3_I2C0SDA);
  
  I2CMasterInitExpClk(I2C0_MASTER_BASE, SysCtlClockGet(), false);//false for 100kHz mode 
  I2CMasterEnable(I2C0_MASTER_BASE);
  
  UARTprintf("Read TMP102(TEMP SENSOR) \n");
    
  // start I2C transmit
  // Set Point Register in TMP102
  I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, SLAVE_ADDRESS, false);
  tx = 0x00; // TMP102 Point Register is 0x00
  I2CMasterDataPut(I2C0_MASTER_BASE, tx); // Point Register byte to be written  
  while(I2CMasterBusy(I2C0_MASTER_BASE)) {} // Check, the bus isn't busy (low?)
  
  // Single Byte
  I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_SINGLE_SEND);    
  while(I2CMasterBusy(I2C0_MASTER_BASE)) {}    //wait  
  // end I2C transmit  
 
  while(1)
  {
    // start I2C receive
    // Read TEMPERATURE REGISTER
    I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, SLAVE_ADDRESS, true); // set to true since it's a read

    I2CMasterControl(I2C_MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START);
    while(I2CMasterBusy(I2C0_MASTER_BASE)) {}    
    
    rx[0] = I2CMasterDataGet(I2C0_MASTER_BASE);
    
    I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
    while(I2CMasterBusBusy(I2C0_MASTER_BASE)) {}
    
    rx[1] = I2CMasterDataGet(I2C0_MASTER_BASE);
    // end I2C receive
    
    int temperature = ((rx[0] << 8) | rx[1]) >> 4; 
    int celsius = temperature*625;
    UARTprintf("Temperature: %d\n", (int)(celsius/10000)-5);
    
    //UARTprintf("rx[0]: %x\n", rx[0]);  
    //UARTprintf("rx[1]: %x\n", rx[1]);
    SysCtlDelay(5000000);
  }
  return(0);
}