ADC_EXTERNALTRIGCONV_T2_CC2怎么使用

ADC_EXTERNALTRIGCONV_T2_CC2是ADC的外部触发源，使用TIM2的CC2通道触发ADC转换。以下是基于STM32CubeMX和HAL库的代码实现：

1. 配置TIM2和ADC时钟

/* TIM2 clock enable */
__HAL_RCC_TIM2_CLK_ENABLE();

/* ADC1 clock enable */
__HAL_RCC_ADC1_CLK_ENABLE();

2. 配置GPIO引脚和时钟

/* Configure GPIO pin : PA1 */
GPIO_InitStruct.Pin = GPIO_PIN_1;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOA_CLK_ENABLE();

3. 配置TIM2为输出PWM模式，配置ADC为单通道转换模式

/* TIM2 configuration */
htim2.Instance = TIM2;
htim2.Init.Prescaler = 0;
htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
htim2.Init.Period = 999;
htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
HAL_TIM_PWM_Init(&htim2);

/* Configure PWM channel */
sConfigOC.OCMode = TIM_OCMODE_PWM1;
sConfigOC.Pulse = 500;
sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
HAL_TIM_PWM_ConfigChannel(&htim2, &sConfigOC, TIM_CHANNEL_2);

/* ADC configuration */
hadc1.Instance = ADC1;
hadc1.Init.ScanConvMode = DISABLE;
hadc1.Init.ContinuousConvMode = DISABLE;
hadc1.Init.DiscontinuousConvMode = DISABLE;
hadc1.Init.ExternalTrigConv = ADC_EXTERNALTRIGCONV_T2_CC2;
hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc1.Init.NbrOfConversion = 1;
HAL_ADC_Init(&hadc1);

/* Configure Regular Channel */
sConfig.Channel = ADC_CHANNEL_1;
sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
HAL_ADC_ConfigChannel(&hadc1, &sConfig);

4. 配置TIM2的触发源和开启TIM2和ADC

/* Start PWM */
HAL_TIM_PWM_Start(&htim2, TIM_CHANNEL_2);

/* Start ADC conversion */
HAL_ADC_Start(&hadc1);

5. 在ADC转换完成中断中获取采样值

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
{
    /* Get ADC value */
    uint16_t adc_value = HAL_ADC_GetValue(hadc);
    
    /* Do something with the ADC value */
    ...
}

以上是基于STM32CubeMX和HAL库的代码实现，需要根据实际情况进行修改。在这个例子中，TIM2的CC2通道触发ADC转换，所以需要确保TIM2的CC2通道输出的PWM信号能够触发ADC转换。