blinky1/measure.c

/*
 * adc.cpp
 *
 *  Created on: 03.10.2014
 *      Author: wn
 */

#include <msp430g2553.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdbool.h>
#include <float.h>

#include "measure.h"
#include "PontCoopScheduler.h"
#include "pattern.h"


const float R_REF = 1000.0;
const uint16_t N_MAX = 1023;
const float PT1000_R0 = 1000.0;
const float PT1000_Coeff = 3.85e-3;


const uint32_t MEASURE_CYCLE = 20;
const uint32_t MEASURE_FETCH_RESULT_DELAY = 5;
const uint8_t AVERAGING_CYCLES = 50;



void measureCollectAndProcessConversion() {
  
  static uint32_t averagingSum = 0;
  static uint8_t averagingCnt = 0;

  uint16_t n = 0xffff;
  if ((ADC10CTL0 & ADC10IFG) != 0) {
    n = ADC10MEM;
    ADC10CTL0 &= ~(ADC10IFG | ENC);
  }

  if (n != 0xffff) {
    averagingSum += n;
    averagingCnt++;
  }

  if (averagingCnt == AVERAGING_CYCLES)  {
    uint32_t nAvg = averagingSum / averagingCnt;

    // process adcValue
    // store result in variable temperature
    float r = 0.0;
    if (nAvg == 0) {
      r = 0.0;
    } else if (nAvg == N_MAX) {
      r = FLT_MAX;
    } else {
      r = R_REF / ((((float)N_MAX) / ((float)nAvg)) - 1.0);
    }
    float t = (r / PT1000_R0 - 1) / PT1000_Coeff;

    uint8_t temperature = (t < 0) ? 0 : ((uint8_t)t);

    // do something with the temperature
    patternSetTemperature(temperature);

    averagingCnt = 0;
    averagingSum = 0;
  }
}

void measureTestExec() {
  static uint8_t t = 0;
  static int8_t dir = 1;

  if (t == 0) {
    dir = 1;
  }

  if (t == 50) {
    dir = -1; 
  }

  t += dir;

  patternSetTemperature(t);
}

void measureStartConversion() {
  ADC10CTL0 |= ENC | ADC10SC;
  schAdd(measureCollectAndProcessConversion, NULL, MEASURE_FETCH_RESULT_DELAY, 0);
}


void measureInit() {
  ADC10CTL0 = SREF_0 | ADC10SHT_3 | ADC10SR | ADC10ON;
  ADC10CTL1 = INCH_0;
  ADC10AE0 = BIT0;

  schAdd(measureStartConversion, NULL, 0, 100);
//  schAdd(measureTestExec, NULL, 0, 10000);
}