STM32F103 使用并口通讯AD9851输出正弦波，方波，三角波，脉冲波

AD9851 是一款数字频率合成器，能够通过并口通讯控制输出正弦波、方波、三角波和脉冲波等多种波形。下面是使用 STM32F103 控制 AD9851 输出这些波形的示例程序：

#include "stm32f10x.h"

#define AD9851_W_CLK_GPIO    GPIOB
#define AD9851_W_CLK_PIN     GPIO_Pin_12
#define AD9851_FQ_UD_GPIO    GPIOB
#define AD9851_FQ_UD_PIN     GPIO_Pin_13
#define AD9851_DATA_GPIO     GPIOB
#define AD9851_DATA_PIN      GPIO_Pin_15

#define AD9851_RESET_GPIO    GPIOB
#define AD9851_RESET_PIN     GPIO_Pin_14

#define AD9851_W_CLK_SET()   GPIO_SetBits(AD9851_W_CLK_GPIO, AD9851_W_CLK_PIN)
#define AD9851_W_CLK_CLR()   GPIO_ResetBits(AD9851_W_CLK_GPIO, AD9851_W_CLK_PIN)
#define AD9851_FQ_UD_SET()   GPIO_SetBits(AD9851_FQ_UD_GPIO, AD9851_FQ_UD_PIN)
#define AD9851_FQ_UD_CLR()   GPIO_ResetBits(AD9851_FQ_UD_GPIO, AD9851_FQ_UD_PIN)
#define AD9851_DATA_SET()    GPIO_SetBits(AD9851_DATA_GPIO, AD9851_DATA_PIN)
#define AD9851_DATA_CLR()    GPIO_ResetBits(AD9851_DATA_GPIO, AD9851_DATA_PIN)
#define AD9851_RESET_SET()   GPIO_SetBits(AD9851_RESET_GPIO, AD9851_RESET_PIN)
#define AD9851_RESET_CLR()   GPIO_ResetBits(AD9851_RESET_GPIO, AD9851_RESET_PIN)

// AD9851 输出波形类型
typedef enum {
    AD9851_WAVE_SINE    = 0x00,
    AD9851_WAVE_TRIANGLE= 0x02,
    AD9851_WAVE_SQUARE  = 0x04,
    AD9851_WAVE_PULSE   = 0x06
} AD9851_WaveType;

// 向 AD9851 发送一帧数据
void AD9851_Send(uint32_t data) {
    uint8_t i;
    for (i = 0; i < 32; i++) {
        if (data & 0x00000001) {
            AD9851_DATA_SET();
        } else {
            AD9851_DATA_CLR();
        }
        AD9851_W_CLK_SET();
        AD9851_W_CLK_CLR();
        data >>= 1;
    }
}

// 初始化 AD9851
void AD9851_Init(void) {
    GPIO_InitTypeDef GPIO_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    GPIO_InitStructure.GPIO_Pin = AD9851_W_CLK_PIN | AD9851_FQ_UD_PIN | AD9851_DATA_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = AD9851_RESET_PIN;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    AD9851_W_CLK_CLR();
    AD9851_FQ_UD_CLR();
    AD9851_DATA_CLR();
    AD9851_RESET_SET();
    AD9851_RESET_CLR();
}

// 设置 AD9851 输出频率
void AD9851_SetFreq(uint32_t freq) {
    uint32_t phase = 0;
    uint64_t data = 0;

    // 计算相位步进值
    phase = (uint32_t)((double)0xFFFFFFFF * ((double)freq / 125000000.0));
    data = ((uint64_t)phase << 2) | 0x20000000; // 0x20000000 表示幅度为满幅度

    // 发送频率设置帧
    AD9851_FQ_UD_CLR();
    AD9851_Send(data >> 24);
    AD9851_Send(data >> 16);
    AD9851_Send(data >> 8);
    AD9851_Send(data >> 0);
    AD9851_FQ_UD_SET();
}

// 设置 AD9851 输出波形
void AD9851_SetWave(AD9851_WaveType wave) {
    uint64_t data = 0;

    // 发送波形设置帧
    AD9851_FQ_UD_CLR();
    data = ((uint64_t)wave << 8) | 0x40000000; // 0x40000000 表示频率不变
    AD9851_Send(data >> 24);
    AD9851_Send(data >> 16);
    AD9851_Send(data >> 8);
    AD9851_Send(data >> 0);
    AD9851_FQ_UD_SET();
}

int main(void) {
    // 初始化系统时钟和 IO 端口
    SystemInit();
    AD9851_Init();

    // 设置输出频率和波形
    AD9851_SetFreq(1000000); // 设置输出频率为 1MHz
    AD9851_SetWave(AD9851_WAVE_SINE); // 设置输出波形为正弦波

    while (1) {
        // 循环执行
    }
}

注意，在实际使用中需要根据自己的硬件电路和 AD9851 的特性进行适当调整。例如，AD9851 的时钟信号需要在 30MHz 左右，需要使用外部晶振或者 PLL 使系统时钟提高到这个频率。同时，也需要根据 AD9851 的特性设置相应的输出幅度和增益等参数。