# (志航) [STM32]定時器

## 定時器輸入捕獲 PWM占空比

### 定時器TIM
:::success


:::
***
#### 硬體設置

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#### 主要程式碼

#include "main.h"
#include "stdio.h"
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_TIM3_Init(void);
static void MX_USART1_UART_Init(void);

char txBuffer[100];
uint8_t rising_flag = 0;
uint8_t falling_flag = 0;
uint8_t overflow_v = 0;
uint16_t cnt_v = 0;
uint32_t V = 0;

void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)//輸入捕獲
{
	if(htim -> Instance == TIM3 && htim->Channel == HAL_TIM_ACTIVE_CHANNEL_4)
	{
			if(falling_flag == 0){
				if(rising_flag == 1){	
					falling_flag = 1;
					cnt_v = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_4);
					__HAL_TIM_SET_CAPTUREPOLARITY(htim, TIM_CHANNEL_4, TIM_INPUTCHANNELPOLARITY_RISING);
				}else{
					overflow_v = 0;
					cnt_v = 0;
					V = 0;
					rising_flag = 1;    
					__HAL_TIM_DISABLE(htim);
					__HAL_TIM_SET_COUNTER(htim, 0);
					__HAL_TIM_SET_CAPTUREPOLARITY(htim, TIM_CHANNEL_4, TIM_INPUTCHANNELPOLARITY_FALLING);
					__HAL_TIM_ENABLE(htim);
				}
			}
	}
}

int main(void)
{
    HAL_Init();
    SystemClock_Config();
    
    MX_GPIO_Init();
    MX_TIM3_Init();
    MX_USART1_UART_Init();
    
    HAL_TIM_Base_Start_IT(&htim3);
	HAL_TIM_IC_Start_IT(&htim3, TIM_CHANNEL_4);
    while (1)
  {
         if(falling_flag == 1){
	  			V = overflow_v * 65536; // 按鈕按下秒數=溢出次數*(ARR+1) + CNT
	  			V += cnt_v;
	  			sprintf(txBuffer, "PB1_Trigger_time: %ld ms\n", V/1000);
	  			HAL_UART_Transmit(&huart1, (uint8_t *)txBuffer, strlen(txBuffer), 1000);
	  			falling_flag = 0;
	  			rising_flag = 0;
	  		}
  }
}

CCR：比較值或捕獲值，用於輸入捕獲。
ARR：自動重載寄存器，控制計數器的最大值。

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)//記數週期結束觸發
{

	if(htim -> Instance == TIM3 )
	{
		if(rising_flag == 1){
			if((overflow_v & 0xff) == 0xff){
				falling_flag = 1;
				__HAL_TIM_SET_CAPTUREPOLARITY(htim, TIM_CHANNEL_4, TIM_INPUTCHANNELPOLARITY_RISING);
			}else{
				overflow_v ++;
				}
		}
	}
}



MX_TIM2_Init();
HAL_TIM_PWM_Start(&htim2, TIM_CHANNEL_1);

uint8_t PB_ON (GPIO_TypeDef *GPIOx, uint16_t GPIO_Pin){
	uint8_t PB = 0;
	if (HAL_GPIO_ReadPin(GPIOx, GPIO_Pin))
	{
		HAL_Delay(50);
		PB = 1;
	}
	while(HAL_GPIO_ReadPin(GPIOx, GPIO_Pin))
	{
	}
	HAL_Delay(50);
	return PB;
}
void LED_BRI (void){
	if(PB_ON(GPIOD, PB2_Pin)){
		i += 30;
        if (i > 100) {
            i = 0;
        }
		__HAL_TIM_SET_COMPARE(&htim2, TIM_CHANNEL_1, i);
	}
}

#### 成果
{%youtube I9U-Xy01ewM%}
{%youtube I9QaW7QKIJQ%}

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## **實驗進度**
- [x] 6-跑馬燈實驗
- [x] 7-蜂鳴器實驗
- [x] 8-按鈕輸入實驗
- [x] 9-序列埠通訊實驗
- [x] 10-外部中斷實驗
- [x] 12-窗口門狗(WWDG)實驗
- [x] 13-定時器中斷實驗
- [x] 14-PWN輸出實驗
- [ ] 16-電容觸摸按鍵實驗
- [ ] 18-TFTLCD顯示實驗
- [ ] 19-USMART調試組件實驗
- [ ] 20-RTC即時時鐘實驗
- [ ] 23-ADC實驗
- [ ] 29-IIC實驗
- [ ] 30-SPI實驗
- [ ] 36-DHT11數位溫濕度感測器實驗