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今天就进入最后一步，写代码。

首先打开之前生成的工程文件。（代码有专门视频讲解——讲解如何搭建“跳动的心”所需要的开发环境以及其中的细节配置）完善“跳动的心”程序视频

打开main.c文件

可以看到之前配置过的在这里边自动生成，找到刚才的定时器TIM5初始化函数。

static void MX_TIM5_Init(void)

{

TIM_ClockConfigTypeDef sClockSourceConfig;

  TIM_MasterConfigTypeDef sMasterConfig;

  TIM_OC_InitTypeDef sConfigOC;

  htim5.Instance = TIM5;

  htim5.Init.Prescaler = 0;

  htim5.Init.CounterMode = TIM_COUNTERMODE_UP;

  htim5.Init.Period = 0;

  htim5.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;

  if (HAL_TIM_Base_Init(&htim5) != HAL_OK)

  {

    _Error_Handler(__FILE__, __LINE__);

  }

  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;

  if (HAL_TIM_ConfigClockSource(&htim5, &sClockSourceConfig) != HAL_OK)

  {

    _Error_Handler(__FILE__, __LINE__);

  }

  if (HAL_TIM_PWM_Init(&htim5) != HAL_OK)

  {

    _Error_Handler(__FILE__, __LINE__);

  }

  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;

  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;

  if (HAL_TIMEx_MasterConfigSynchronization(&htim5, &sMasterConfig) != HAL_OK)

  {

    _Error_Handler(__FILE__, __LINE__);

  }

  sConfigOC.OCMode = TIM_OCMODE_PWM1;

  sConfigOC.Pulse = 0;

  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;

  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;

  if (HAL_TIM_PWM_ConfigChannel(&htim5, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)

  {

    _Error_Handler(__FILE__, __LINE__);

  }

  HAL_TIM_MspPostInit(&htim5);

}

设置Pulse的值可以修改脉宽。这里在main.c文件中添加一个用户PWM设置函数，函数的参数为修改的值。

void user_pwm_setvalue(uint16_t value)

{

  TIM_OC_InitTypeDef sConfigOC;

  sConfigOC.OCMode = TIM_OCMODE_PWM1;

  sConfigOC.Pulse = value;

  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;

  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;

  HAL_TIM_PWM_ConfigChannel(&htim5, &sConfigOC, TIM_CHANNEL_1);

  HAL_TIM_PWM_Start(&htim5, TIM_CHANNEL_1);  

}

然后在main.c文件中添加心率传感器的驱动程序

下面是驱动定义的变量

// these variables are volatile because they are used during the interrupt service routine!

#define true 1

#define false 0

int BPM;                   // used to hold the pulse rate

int Signal;                // holds the incoming raw data

int IBI = 600;             // holds the time between beats, must be seeded!

unsigned char Pulse = false;     // true when pulse wave is high, false when it's low

unsigned char QS = false;        // becomes true when Arduoino finds a beat.

int rate[10];                    // array to hold last ten IBI values

unsigned long sampleCounter = 0;          // used to determine pulse timing

unsigned long lastBeatTime = 0;           // used to find IBI

int P =512;                      // used to find peak in pulse wave, seeded

int T = 512;                     // used to find trough in pulse wave, seeded

int thresh = 512;                // used to find instant moment of heart beat, seeded

int amp = 100;                   // used to hold amplitude of pulse waveform, seeded

int Num;

unsigned char firstBeat = true;     // used to seed rate array so we startup with reasonableBPM

unsigned char secondBeat = false;  // used to seed rate array so we startup with reasonableBPM

然后是驱动程序

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)

{

unsigned int runningTotal;

if(htim->Instance==htim9.Instance)

{

Signal=HAL_ADC_GetValue(&hadc1);  // read the Pulse Senso

sampleCounter += 2;                         // keep track of the time in mS with this variable

Num = sampleCounter - lastBeatTime;       // monitor the time since the last beat to avoid noise

HAL_ADC_Start(&hadc1); //restart ADC conversion

//  find the peak and trough of the pulse wave

  if(Signal < thresh && Num > (IBI/5)*3){       // avoid dichrotic noise by waiting 3/5 of last IBI

    if (Signal < T){                        // T is the trough

      T = Signal;                         // keep track of lowest point in pulse wave

    }

  }

  if(Signal > thresh && Signal > P){          // thresh condition helps avoid noise

    P = Signal;                             // P is the peak

  }                                        // keep track of highest point in pulse wave

  //  NOW IT'S TIME TO LOOK FOR THE HEART BEAT

  // signal surges up in value every time there is a pulse

  if (Num > 250){                                   // avoid high frequency noise

    if ( (Signal > thresh) && (Pulse == false) && (Num > (IBI/5)*3) ){        

      Pulse = true;                               // set the Pulse flag when we think there is a pulse

      HAL_GPIO_WritePin(GPIOA,GPIO_PIN_5,GPIO_PIN_SET);                // turn on pin 13 LED

      IBI = sampleCounter - lastBeatTime;         // measure time between beats in mS

      lastBeatTime = sampleCounter;               // keep track of time for next pulse

      if(secondBeat){                        // if this is the second beat, if secondBeat == TRUE

        secondBeat = false;                  // clear secondBeat flag

        for(int i=0; i<=9; i++){             // seed the running total to get a realisitic BPM at startup

          rate[i] = IBI;                      

        }

      }

      if(firstBeat){                         // if it's the first time we found a beat, if firstBeat == TRUE

        firstBeat = false;                   // clear firstBeat flag

        secondBeat = true;                   // set the second beat flag

 //       sei();                               // enable interrupts again

        return;                              // IBI value is unreliable so discard it

      }   

      // keep a running total of the last 10 IBI values

      runningTotal = 0;                  // clear the runningTotal variable    

      for(int i=0; i<=8; i++){                // shift data in the rate array

        rate[i] = rate[i+1];                  // and drop the oldest IBI value

        runningTotal += rate[i];              // add up the 9 oldest IBI values

      }

      rate[9] = IBI;                          // add the latest IBI to the rate array

      runningTotal += rate[9];                // add the latest IBI to runningTotal

      runningTotal /= 10;                     // average the last 10 IBI values

      BPM = 60000/runningTotal;       // how many beats can fit into a minute? that's BPM!

      QS = true;                              // set Quantified Self flag

      // QS FLAG IS NOT CLEARED INSIDE THIS ISR

    }                       

  }

  if (Signal < thresh && Pulse == true){   // when the values are going down, the beat is over

     HAL_GPIO_WritePin(GPIOA,GPIO_PIN_5,GPIO_PIN_RESET);        // turn off pin 13 LED

    Pulse = false;                         // reset the Pulse flag so we can do it again

    amp = P - T;                           // get amplitude of the pulse wave

    thresh = amp/2 + T;                    // set thresh at 50% of the amplitude

    P = thresh;                            // reset these for next time

    T = thresh;

  }

  if (Num > 2500){                           // if 2.5 seconds go by without a beat

    thresh = 512;                          // set thresh default

    P = 512;                               // set P default

    T = 512;                               // set T default

    lastBeatTime = sampleCounter;          // bring the lastBeatTime up to date        

    firstBeat = true;                      // set these to avoid noise

    secondBeat = false;                    // when we get the heartbeat back

  }

}

}

最后在主函数中，添加代码

（快去看楼主小哥哥嗓子发炎依旧坚持录制的配套视频）

大家也可以在自己制作的过程中，通过改变延时函数和变量的大小来达到不同的效果，楼主在配置过程中可是尝试了很多不同的变量大小，呈现了很多不同的效果，也从中得到了很多有趣的东西，至于是哪些有趣的东西，等各位萌新自己制作出来，自己要记得调试哦，欢迎在下面留言发表你看到的不同的效果和你认为的有趣的东西。最棒的那位萌新，你的建议会帮助到许许多多的人的~~~也欢迎留言分享在制作过程中遇到的困难和心得~~