//-----------------------------------------------------------------------------
// MSP430F169 TMP100 I2C Slave Emulation II
//
// Uses ADC12 and I2C modules to emulate behaviour of the TMP100
// temperature sensor.
//
// - DMA services I2C module (transmit and receive)
// - Timer_A triggers ADC12 temperature conversion every 1/10s
//
//   +--------------------+
//   |                    |
//   |                    |
//   |                    |
//   |               P3.1 +<------> I2C SDA
//   |               P3.3 +<------- I2C SCL
//   |  MSP430F169        |
//   |                    |
//   |                    |
//   |                    |
//   |                    |
//   |                    |
//   +--------------------+
//
//
// Andreas Dannenberg
// MSP430 Applications
// Texas Instruments Inc.
// August 2003
//
// History:  V1.01 (08/29/03)
//           - I2C enable sequence corrected
//           V1.00 (08/28/03)
//           - initial release
//-----------------------------------------------------------------------------
#include <msp430x16x.h>
//-----------------------------------------------------------------------------
#define TMPADDR              0x48                // TMP100 Slave Address with
                                                 // A0=A1=A2=0

void Init_Sys(void);                             // function prototype

static unsigned int ADCResult;                   // holds the last ADC result
static unsigned int CurrentTmp;                  // holds current temperature
                                                 // to be transmitted
static unsigned int ReceivedWord;                // 
//----------------------------------------------------------------------------- 
// ADC12 Module Temperature Table
//
// These values assume nominal values for the temp diode and
// temperature coefficient. They also assume the 2.5V internal
// reference is used for the conversion. The transfer function out
// of Figure 17-10 of the MSP430x1xx Family User's Guide (SLAU049C)
// has been used.
//-----------------------------------------------------------------------------
static const unsigned int Temp_Tab[] =
{
  0x064F,                                        // 0C
  0x0655,
  0x065B,
  0x0660,
  0x0666,
  0x066C,                                        // 5C
  0x0672,
  0x0678,
  0x067D,
  0x0683,
  0x0689,                                        // 10C
  0x068F,
  0x0695,
  0x069B,
  0x06A0,
  0x06A6,                                        // 15C
  0x06AC,
  0x06B2,
  0x06B8,
  0x06BD,
  0x06C3,                                        // 20C
  0x06C9,
  0x06CF,
  0x06D5,
  0x06DB,
  0x06E0,                                        // 25C
  0x06E6,
  0x06EC,
  0x06F2,
  0x06F8,
  0x06FD,                                        // 30C
  0x0703,
  0x0709,
  0x070F,
  0x0715,
  0x071B,                                        // 35C
  0x0720,
  0x0726,
  0x072C,
  0x0732,
  0x0738,                                        // 40C
  0x073D,
  0x0743,
  0x0749,
  0x074F,
  0x0755,                                        // 45C
  0x0FFF                                         // Too high
};
//-----------------------------------------------------------------------------
void main(void)
{
  unsigned int i;

  Init_Sys();                                    // initialize system
  _EINT();                                       // enable interrupts
  
  while (1)                                      // repeat forever
  {
    _BIS_SR(LPM3);                               // wait for ADC conversion
                                                 // completion
  
    for (i = 0; i < sizeof Temp_Tab; i++)        // get temperature value out
      if (ADCResult < Temp_Tab[i])               // of table
        break;

    _DINT();                                     // protect next statement
    CurrentTmp = i;                              // save current temperature
    _EINT();
  }
}
//-----------------------------------------------------------------------------
// setup system and peripherals
//-----------------------------------------------------------------------------
void Init_Sys(void)
{
  WDTCTL = WDTPW + WDTHOLD;                      // stop watchdog timer
  BCSCTL1 = XT2OFF + RSEL2 + RSEL0;              // adjust DCO frequ
  
  // D169 specific initialisation
  P1OUT = 0x10;                                  // disable audio output stage
  P1DIR = 0x3f;                                  // P1.6/P1.7 inp, all other outp
  P2OUT = 0x00;                                  // clear P2 output register
  P2DIR = 0xff;                                  // unused pins as outp  
  P3SEL = 0x0a;                                  // assign I2C pins to module
  P3OUT = 0x00;                                  // clear P3 output register
  P3DIR = 0xff;                                  // unused pins as outp  
  P4OUT = 0x00;                                  // clear P4 output register
  P4DIR = 0xff;                                  // unused pins as outp  
  P5OUT = 0x00;                                  // clear P5 output register
  P5DIR = 0xff;                                  // unused pins as outp  
  P6OUT = 0x00;                                  // clear P6 output register
  P6DIR = 0xfe;                                  // unused pins as outp  

  // Setup I2C module
  U0CTL |= I2C + SYNC;                           // switch USART0 to I2C mode
  U0CTL = RXDMAEN + TXDMAEN;                     // enable I2C DMA triggers
  I2COA = TMPADDR;                               // own address = TMP100 device addr
  I2CTCTL = I2CWORD + I2CSSEL1;                  // select SMCLK, word mode
  U0CTL |= I2CEN;                                // enable I2C module, 7 bit addr,
                                                 // slave mode
                                                 
  // Setup DMA
  DMACTL0 = DMA0TSEL2 + DMA1TSEL1 + DMA1TSEL0;   // I2C transmit ready -> DMA0
                                                 // I2C receive ready -> DMA1
  DMA0SA = (int)&CurrentTmp;
  DMA0DA = I2CDRW_;
  DMA0CTL = DMADT2 + DMAEN;                      // Repeated single transfer
  DMA1SA = I2CDRW_;
  DMA1DA = (int)&ReceivedWord;
  DMA1CTL = DMADT2 + DMAEN;                      // Repeated single transfer

  // Setup Timer_A
  CCR0 = 3277;                                   // 1/10s w/ 32kHz ACLK
  CCR1 = 3276;                                   // ADC12 start-of-conversion
  TACCTL1 = OUTMOD_3;                            // set on EQU1, reset on EQU0
  TACTL = TASSEL_1 + MC0;                        // ACLK, start timer in up-mode

  // Setup ADC12
  ADC12CTL0 = ADC12ON + REFON + REF2_5V + SHT0_6;// Turn on ADC12, 2.5Vref, set SHT0
                                                 // for longer sampling required by
                                                 // temp diode.
  ADC12CTL1 = SHS_1 + SHP + CONSEQ_2;            // Use sampling timer, Timer_A.OUT1
                                                 // triggers conversion, rep. single
                                                 // channel
  ADC12MCTL0 = INCH_10 + SREF_1;                 // Select channel A10, Vref+
  ADC12IE = 0x01;                                // enable ADC12IFG.0 for ADC12MEM0            
  ADC12CTL0 |= ENC;                              // Enable conversions
}
//----------------------------------------------------------------------------- 
// Interrupt Service Routine for ADC12
//-----------------------------------------------------------------------------
interrupt[ADC_VECTOR]  void ADC12ISR(void)
{
  ADCResult = ADC12MEM0;                         // Move result, IFG is cleared
  _BIC_SR_IRQ(LPM3_bits);                        // Return active
}