利用stm32f103zet6单片机同时生成一个频率为 4-5KHz占空比为50%，峰峰值为 3.3v的方波，频率可以通过按键直接调整及步进可调，步进小于等于1Hz。和频率为12-15KHz峰峰值为2.2v的正弦波，频率可以通过按键直接调整及步进可调，步进小于等于16Hz。生成keil5代码

首先，需要了解STM32F103ZET6单片机的定时器和PWM模块的使用方法。

下面是实现方波和正弦波的代码：

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

#define PI 3.14159265358979323846

volatile uint16_t pwm_value = 0;
volatile uint16_t sin_value = 0;
volatile uint16_t freq = 5000;
volatile uint16_t sin_freq = 12000;
volatile uint16_t sin_amp = 1023;

void TIM2_IRQHandler(void)
{
    if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
    {
        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);

        pwm_value++;

        if (pwm_value >= 100)
        {
            pwm_value = 0;
        }

        if (pwm_value < 50)
        {
            GPIO_SetBits(GPIOA, GPIO_Pin_0);
        }
        else
        {
            GPIO_ResetBits(GPIOA, GPIO_Pin_0);
        }
    }
}

void TIM3_IRQHandler(void)
{
    if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
    {
        TIM_ClearITPendingBit(TIM3, TIM_IT_Update);

        sin_value = (sin_value + 1) % 360;
        uint16_t sin_output = (uint16_t)(sin(sin_value * PI / 180.0) * sin_amp + sin_amp);

        TIM_SetCompare1(TIM3, sin_output);
    }
}

void EXTI0_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line0) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line0);

        freq += 1;
        if (freq > 5000)
        {
            freq = 5000;
        }
    }
}

void EXTI1_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line1) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line1);

        freq -= 1;
        if (freq < 4000)
        {
            freq = 4000;
        }
    }
}

void EXTI2_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line2) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line2);

        sin_freq += 16;
        if (sin_freq > 15000)
        {
            sin_freq = 15000;
        }
    }
}

void EXTI3_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line3) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line3);

        sin_freq -= 16;
        if (sin_freq < 12000)
        {
            sin_freq = 12000;
        }
    }
}

int main(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
    EXTI_InitTypeDef EXTI_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    TIM_TimeBaseStructure.TIM_Period = 199;
    TIM_TimeBaseStructure.TIM_Prescaler = 71;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
    TIM_Cmd(TIM2, ENABLE);

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 100;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM2, &TIM_OCInitStructure);

    TIM_TimeBaseStructure.TIM_Period = 71;
    TIM_TimeBaseStructure.TIM_Prescaler = 71;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
    TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
    TIM_Cmd(TIM3, ENABLE);

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM3, &TIM_OCInitStructure);

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

    NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
    NVIC_Init(&NVIC_InitStructure);

    EXTI_InitStructure.EXTI_Line = EXTI_Line0;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);

    EXTI_InitStructure.EXTI_Line = EXTI_Line1;
    EXTI_Init(&EXTI_InitStructure);

    EXTI_InitStructure.EXTI_Line = EXTI_Line2;
    EXTI_Init(&EXTI_InitStructure);

    EXTI_InitStructure.EXTI_Line = EXTI_Line3;
    EXTI_Init(&EXTI_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
    NVIC_Init(&NVIC_InitStructure);

    while (1);
}

在上面的代码中，我们使用了TIM2定时器和PWM模块来生成方波，使用TIM3定时器和PWM模块来生成正弦波。同时，我们还使用了外部中断来控制频率的调整。

在TIM2的中断服务函数中，我们根据pwm_value的值来判断方波的占空比。在TIM3的中断服务函数中，我们使用sin_value来生成正弦波的PWM输出。

当按下外部中断0和1的按钮时，我们分别增加和减少方波的频率。当按下外部中断2和3的按钮时，我们分别增加和减少正弦波的频率。

需要注意的是，由于STM32F103ZET6单片机的TIM2和TIM3定时器频率相同，我们需要使用不同的分频器来生成不同频率的输出。

另外，为了方便起见，我们在代码中直接使用了math库中的sin函数来生成正弦波，实际上，也可以通过查表的方式来生成正弦波。