STM32F4ZGT6 示波器制作教程及案例

制作示波器需要以下步骤：

配置 ADC 模块，将模拟信号转换成数字信号；
配置 DAC 模块，将数字信号转换成模拟信号；
配置 DMA 模块，实现 ADC 和 DAC 之间的数据传输；
配置定时器模块，实现定时采样和更新 DAC 输出；
配置中断模块，实现数据处理和显示。

以下是一个基于 STM32F407ZGT6 的示波器案例：

配置 ADC 模块：

首先，需要配置 ADC 模块以将模拟信号转换为数字信号。我们选择使用 ADC1 和 ADC2 两个通道进行采样。以下是 ADC 配置代码：

RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2, ENABLE);

ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_CommonStructInit(&ADC_CommonInitStructure);
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInit(&ADC_CommonInitStructure);

ADC_InitTypeDef ADC_InitStructure;
ADC_StructInit(&ADC_InitStructure);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 2;
ADC_Init(ADC1, &ADC_InitStructure);
ADC_Init(ADC2, &ADC_InitStructure);

ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_15Cycles);
ADC_RegularChannelConfig(ADC2, ADC_Channel_1, 1, ADC_SampleTime_15Cycles);

ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
ADC_DMARequestAfterLastTransferCmd(ADC2, ENABLE);
ADC_DMACmd(ADC1, ENABLE);
ADC_DMACmd(ADC2, ENABLE);

ADC_Cmd(ADC1, ENABLE);
ADC_Cmd(ADC2, ENABLE);

配置 DAC 模块：

接下来，需要配置 DAC 模块以将数字信号转换为模拟信号。我们选择使用 DAC1 通道来输出信号。以下是 DAC 配置代码：

RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);

DAC_InitTypeDef DAC_InitStructure;
DAC_StructInit(&DAC_InitStructure);
DAC_InitStructure.DAC_Trigger = DAC_Trigger_None;
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bit0;
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
DAC_Init(DAC_Channel_1, &DAC_InitStructure);

DAC_Cmd(DAC_Channel_1, ENABLE);

配置 DMA 模块：

为了实现 ADC 和 DAC 之间的数据传输，我们需要配置 DMA 模块。以下是 DMA 配置代码：

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);

DMA_InitTypeDef DMA_InitStructure;
DMA_StructInit(&DMA_InitStructure);
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC_Buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = ADC_BUFFER_SIZE * 2;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA1_Stream0, &DMA_InitStructure);

DMA_InitStructure.DMA_Channel = DMA_Channel_7;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&DAC->DHR12R1;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&DAC_Buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_BufferSize = ADC_BUFFER_SIZE;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_Init(DMA1_Stream5, &DMA_InitStructure);

DMA_Cmd(DMA1_Stream0, ENABLE);
DMA_Cmd(DMA1_Stream5, ENABLE);

配置定时器模块：

为了实现定时采样和更新 DAC 输出，我们需要配置定时器模块。以下是定时器配置代码：

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Period = 1000;
TIM_TimeBaseStructure.TIM_Prescaler = 84 - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);
TIM_Cmd(TIM2, ENABLE);

配置中断模块：

最后，我们需要配置中断模块以实现数据处理和显示。以下是中断配置代码：

NVIC_InitTypeDef NVIC_InitStructure;
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

DMA_ITConfig(DMA1_Stream0, DMA_IT_TC, ENABLE);

void DMA1_Stream0_IRQHandler(void)
{
    if (DMA_GetITStatus(DMA1_Stream0, DMA_IT_TCIF0) != RESET)
    {
        DMA_ClearITPendingBit(DMA1_Stream0, DMA_IT_TCIF0);

        for (int i = 0; i < ADC_BUFFER_SIZE; i++)
        {
            DAC_Buffer[i] = ADC_Buffer[i * 2];
        }
    }
}

以上是一个基于 STM32F407ZGT6 的示波器案例。此示波器将模拟信号采样并转换为数字信号，然后将数字信号转换为模拟信号并输出。通过定时器模块和 DMA 模块，示波器可以实现定时采样和更新 DAC 输出。最后，通过中断模块，示波器可以对数据进行处理和显示。