#include "stm32f10x.h"
#include <math.h>

#define SINE_WAVE_FREQ      1000    // 1kHz正弦波
#define SAMPLE_RATE         20000   // 采样率20kHz（每个周期20个点）
#define DAC_BUFFER_SIZE     20      // 缓冲区大小（一个周期的点数）

// 手动定义π值（解决M_PI未定义问题）
#define PI 3.14159265358979323846

uint16_t sineWave[DAC_BUFFER_SIZE]; // 正弦波数据缓冲区

void RCC_Config(void) {
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC | RCC_APB1Periph_TIM6, ENABLE);
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE); // DAC DMA使用DMA2
}

void GPIO_Config(void) {
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4; // PA4对应DAC1
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN; // 模拟输入模式（DAC专用）
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void DAC_Config(void) {
    DAC_InitTypeDef DAC_InitStructure;
    DAC_InitStructure.DAC_Trigger = DAC_Trigger_T6_TRGO; // TIM6触发DAC
    DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
    DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
    DAC_Init(DAC_Channel_1, &DAC_InitStructure);
    DAC_Cmd(DAC_Channel_1, ENABLE);
}

void DMA_Config(void) {
    DMA_InitTypeDef DMA_InitStructure;
    DMA_DeInit(DMA2_Channel3); // DAC1使用DMA2通道3
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&DAC->DHR12R1;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)sineWave;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
    DMA_InitStructure.DMA_BufferSize = DAC_BUFFER_SIZE;
    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_M2M = DMA_M2M_Disable;
    DMA_Init(DMA2_Channel3, &DMA_InitStructure);
    DMA_Cmd(DMA2_Channel3, ENABLE);
    DAC_DMACmd(DAC_Channel_1, ENABLE); // 启用DAC DMA
}

void TIM6_Config(void) {
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_TimeBaseStructure.TIM_Period = (SystemCoreClock / SAMPLE_RATE) - 1;
    TIM_TimeBaseStructure.TIM_Prescaler = 0;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM6, &TIM_TimeBaseStructure);
    TIM_SelectOutputTrigger(TIM6, TIM_TRGOSource_Update); // 触发DAC
    TIM_Cmd(TIM6, ENABLE);
}

void GenerateSineWave(void) {
    for (int i = 0; i < DAC_BUFFER_SIZE; i++) {
        float angle = 2 * PI * i / DAC_BUFFER_SIZE; // 使用手动定义的PI
        sineWave[i] = (uint16_t)((sin(angle) + 1) * 2047); // 修正括号并映射到12位DAC范围
    }
}

int main(void) {
    SystemInit();
    RCC_Config();
    GPIO_Config();
    GenerateSineWave();
    DMA_Config();
    DAC_Config();
    TIM6_Config();

    while (1) {
        __WFI(); // 进入低功耗模式
    }
}
