/*
 * thermometer.c
 *
 *  Created on: Jun 13, 2017
 *      Author: wn
 */


#include "stm32f1xx_hal.h"
#include "thermometer.h"
#include <PontCoopScheduler.h>


extern ADC_HandleTypeDef hadc1;


#define NUM_OF_CONV 10

uint16_t adcBuf[NUM_OF_CONV];
volatile uint32_t value;

const float R_REF = 1000.0;
const uint16_t N_MAX = 4095;
const float PT1000_R0 = 1000.0;
const float PT1000_Coeff = 3.85e-3;



void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc) {
  HAL_ADC_Stop_DMA(hadc);

  uint32_t sum = 0;
  for (uint8_t i = 0; i < NUM_OF_CONV; i++) {
    sum += adcBuf[i];
  }
  uint32_t avg = sum / NUM_OF_CONV;
  value = avg;
}

void thermometerStartCycle(void *handle) {
  HAL_ADC_Start_DMA(&hadc1, ((uint32_t*)adcBuf), NUM_OF_CONV);
}

void thermometerInit() {
  HAL_ADCEx_Calibration_Start(&hadc1);
  schAdd(thermometerStartCycle, NULL, 0, 100);
}

uint32_t thermometerGetValue() {
  float r = R_REF / ((((float)N_MAX) / ((float)value)) - 1.0);
  float t = ((r / PT1000_R0) - 1) / PT1000_Coeff;
  uint32_t tn = (t < 0) ? 0 : (uint16_t)t;
  return tn;
}