单片机收音机程序

这里提供一个基于STM32单片机的简单收音机程序，仅供参考：

#include "stm32f4xx.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_tim.h"
#include "stm32f4xx_dma.h"
#include "stm32f4xx_adc.h"

#define ADC3_DR_ADDRESS     ((uint32_t)0x4001224C)

uint16_t ADC3ConvertedValue[1024];

void GPIO_Configuration(void);
void DMA_Configuration(void);
void ADC_Configuration(void);
void TIM_Configuration(void);

int main(void)
{
  GPIO_Configuration();
  DMA_Configuration();
  ADC_Configuration();
  TIM_Configuration();

  while (1)
  {
  }
}

void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOC, &GPIO_InitStructure);
}

void DMA_Configuration(void)
{
  DMA_InitTypeDef DMA_InitStructure;

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);

  DMA_InitStructure.DMA_Channel = DMA_Channel_2;
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC3_DR_ADDRESS;
  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC3ConvertedValue;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
  DMA_InitStructure.DMA_BufferSize = 1024;
  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(DMA2_Stream0, &DMA_InitStructure);

  DMA_Cmd(DMA2_Stream0, ENABLE);
}

void ADC_Configuration(void)
{
  ADC_InitTypeDef ADC_InitStructure;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE);

  ADC_CommonInitTypeDef 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_InitStructure.ADC_Resolution = ADC_Resolution_12b;
  ADC_InitStructure.ADC_ScanConvMode = DISABLE;
  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
  ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
  ADC_InitStructure.ADC_NbrOfConversion = 1;
  ADC_Init(ADC3, &ADC_InitStructure);

  ADC_RegularChannelConfig(ADC3, ADC_Channel_10, 1, ADC_SampleTime_15Cycles);

  ADC_DMARequestAfterLastTransferCmd(ADC3, ENABLE);

  ADC_Cmd(ADC3, ENABLE);

  ADC_SoftwareStartConv(ADC3);
}

void TIM_Configuration(void)
{
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

  TIM_TimeBaseStructure.TIM_Period = 84000 / 8000;
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

  TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

  NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  TIM_Cmd(TIM2, ENABLE);
}

void TIM2_IRQHandler(void)
{
  if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
  {
    TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
    DMA_Cmd(DMA2_Stream0, DISABLE);
    ADC_Cmd(ADC3, DISABLE);
    TIM_Cmd(TIM2, DISABLE);

    uint16_t max = 0;
    for (int i = 0; i < 1024; i++)
    {
      if (ADC3ConvertedValue[i] > max)
      {
        max = ADC3ConvertedValue[i];
      }
    }

    if (max > 2000)
    {
      GPIO_SetBits(GPIOA, GPIO_Pin_5);
    }
    else
    {
      GPIO_ResetBits(GPIOA, GPIO_Pin_5);
    }

    ADC_SoftwareStartConv(ADC3);
    DMA_Cmd(DMA2_Stream0, ENABLE);
    ADC_Cmd(ADC3, ENABLE);
    TIM_Cmd(TIM2, ENABLE);
  }
}

该程序使用的是ADC3、DMA2和TIM2模块，其中ADC3用于将声音信号转换为数字信号，DMA2用于将转换的数据存储到数组中，TIM2用于定时触发转换和处理转换结果。在程序中，我们将PC0口配置为模拟输入，连接到收音机模块的输出端，使用DMA2将转换结果存储到ADC3ConvertedValue数组中，每次TIM2定时器触发中断时对数组进行处理，获取最大值并根据阈值控制GPIO输出。注意，该程序仅作为简单示例，实际使用中需要根据具体的硬件和场景进行调整。