嵌入式开发，Stm32芯片外接RGB模块，实现按下按键，亮起一个灯，按下三次之后，所有灯熄灭

为了实现按下按键亮起一个灯，按下三次之后所有灯熄灭的功能，可以使用状态机的思想，通过判断按键的状态和次数来控制灯的亮灭。具体实现步骤如下：

1.首先需要初始化按键和LED模块，可以使用外部中断和定时器来实现按键的检测和LED的控制。可以参考以下代码：

#include "stm32f10x.h"
#include "led.h"

#define KEY_GPIO_PORT   GPIOA
#define KEY_GPIO_PIN    GPIO_Pin_0

#define LED_GPIO_PORT   GPIOB
#define LED_GPIO_PIN_R  GPIO_Pin_0
#define LED_GPIO_PIN_G  GPIO_Pin_1
#define LED_GPIO_PIN_B  GPIO_Pin_2

uint8_t key_state = 0;  // 按键状态
uint8_t key_count = 0;  // 按键计数

void KEY_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    EXTI_InitTypeDef EXTI_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);

    GPIO_InitStructure.GPIO_Pin = KEY_GPIO_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;    GPIO_Init(KEY_GPIO_PORT, &GPIO_InitStructure);

    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0);

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

    NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

void LED_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    GPIO_InitStructure.GPIO_Pin = LED_GPIO_PIN_R | LED_GPIO_PIN_G | LED_GPIO_PIN_B;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(LED_GPIO_PORT, &GPIO_InitStructure);
}

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

        if (GPIO_ReadInputDataBit(KEY_GPIO_PORT, KEY_GPIO_PIN) == RESET)
        {
            key_state = 1;
        }
    }
}

2.然后需要实现状态机的逻辑，可以参考以下代码：

void LED_Control(uint8_t r, uint8_t g, uint8_t b)
{
    if (r)
    {
        GPIO_SetBits(LED_GPIO_PORT, LED_GPIO_PIN_R);
    }
    else
    {
        GPIO_ResetBits(LED_GPIO_PORT, LED_GPIO_PIN_R);
    }

    if (g)
    {
        GPIO_SetBits(LED_GPIO_PORT, LED_GPIO_PIN_G);
    }
    else
    {
        GPIO_ResetBits(LED_GPIO_PORT, LED_GPIO_PIN_G);
    }

    if (b)
    {
        GPIO_SetBits(LED_GPIO_PORT, LED_GPIO_PIN_B);
    }
    else
    {
        GPIO_ResetBits(LED_GPIO_PORT, LED_GPIO_PIN_B);
    }
}

void StateMachine(void)
{
    static uint8_t state = 0;
    static uint32_t time = 0;

    switch (state)
    {
        case 0:
            if (key_state == 1)
            {
                key_state = 0;
                state = 1;
                time = 0;
                LED_Control(1, 0, 0);
            }
            break;

        case 1:
            if (key_state == 0)
            {
                state = 0;
                LED_Control(0, 0, 0);
            }
            else
            {
                time++;

                if (time >= 1000)
                {
                    state = 2;
                    time = 0;
                    LED_Control(0, 1, 0);
                }
            }
            break;

        case 2:
            if (key_state == 0)
            {
                state = 0;
                LED_Control(0, 0, 0);
            }
            else
            {
                time++;

                if (time >= 1000)
                {
                    state = 3;
                    time = 0;
                    LED_Control(0, 0, 1);
                }
            }
            break;

        case 3:
            if (key_state == 0)
            {
                state = 0;
                key_count = 0;
                LED_Control(0, 0, 0);
            }
            else
            {
                time++;

                if (time >= 1000)
                {
                    time = 0;
                    key_count++;

                    if (key_count >= 3)
                    {
                        state = 4;
                        LED_Control(0, 0, 0);
                    }
                    else
                    {
                        state = 1;
                        LED_Control(1, 0, 0);
                    }
                }
            }
            break;

        case 4:
            if (key_state == 0)
            {
                state = 0;
                key_count = 0;
                LED_Control(0, 0, 0);
            }
            break;

        default:
            break;
    }
}

3.最后在主函数中循环调用状态机即可：

int main(void)
{
    KEY_Init();
    LED_Init();

    while (1)
    {
        StateMachine();
    }
}