/*
 * misc.c
 *
 *  Created on: 21 Sep 2016
 *      Author: Mike
 */
#include "stm32f1xx_hal.h"
#include "misc.h"
#include "main.h"

// this is set if there is a timer timeout interrupt
unsigned char volatile periodPulse = 0;

// this is set when timer 3 was triggerd 
unsigned char volatile tim3triggered = 0;

// this is exported 
void
triggerTim3(void)
{
  htim3.Instance->CNT = 0;
  htim3.Instance->CR1 |= TIM_CR1_CEN;
}

// timer variable shared between TIM3 and TIM4 handler.
static char chtTimer = 0;

void TIM3_IRQHandler(void)
{
  if (__HAL_TIM_GET_FLAG(&htim3, TIM_FLAG_UPDATE))
  {
    __HAL_TIM_CLEAR_FLAG(&htim3, TIM_FLAG_UPDATE);

    tim3triggered = 0;
    if (chtTimer >= 3) // every 300mS
    {
      chtTimer = 0;

      resetTempCS();
      for (int instance = 0; instance < NUM_SPI_TEMP_SENS; instance++)
      {
        uint8_t buffer[2];

        nextTempCS();
        HAL_SPI_Receive(&hspi1, buffer, 2, 2);

        uint16_t obs = (buffer[0] << 8) | buffer[1];

        // good observation if the status bit is clear, and the reading is less than 1023

        uint16_t temp_c = obs >> 5;

        uint8_t good = ((obs & 7) == 0) && (temp_c > 0) && (temp_c < 250);

        if (good)
        {
          Temp_Observations[instance] = temp_c;
        }
      }
      nextTempCS(); // clock CS one more time to deselect all chips
    }
  }
}

// 100mS periodic sampler handler
void TIM4_IRQHandler(void)
{
  static char blink = 0;
  if (__HAL_TIM_GET_FLAG(&htim4, TIM_FLAG_UPDATE))
  {
    __HAL_TIM_CLEAR_FLAG(&htim4, TIM_FLAG_UPDATE);

    blink = !blink;
    HAL_GPIO_WritePin(LED_Blink_GPIO_Port, LED_Blink_Pin,
                      blink ? GPIO_PIN_SET : GPIO_PIN_RESET);


    if (periodPulse == 1)
    {
      triggerTim3();
    }
    // indicate that timer 4 firing is owning the timer 3 trigger
    periodPulse = 1;

    chtTimer++;
  }
}