用中断写stm32矩阵键盘代码

以下是一个简单的基于中断的STM32矩阵键盘代码示例。假设我们使用的是4x4的矩阵键盘。

#include "stm32f10x.h"

#define KEYPAD_PORT GPIOA
#define ROW_1 GPIO_Pin_0
#define ROW_2 GPIO_Pin_1
#define ROW_3 GPIO_Pin_2
#define ROW_4 GPIO_Pin_3
#define COL_1 GPIO_Pin_4
#define COL_2 GPIO_Pin_5
#define COL_3 GPIO_Pin_6
#define COL_4 GPIO_Pin_7

void Keypad_Init(void);
void Keypad_Scan(void);

uint8_t Keypad_Buffer; // 存储按下的键值

int main(void)
{
    Keypad_Init();
    while (1) {
        // 在主循环中不需要做任何事情，因为中断会处理按键事件。
    }
}

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

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

    GPIO_InitStructure.GPIO_Pin = ROW_1 | ROW_2 | ROW_3 | ROW_4;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(KEYPAD_PORT, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = COL_1 | COL_2 | COL_3 | COL_4;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(KEYPAD_PORT, &GPIO_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    EXTI_ClearITPendingBit(EXTI_Line0 | EXTI_Line1 | EXTI_Line2 | EXTI_Line3);
    EXTI_InitStructure.EXTI_Line = EXTI_Line0 | EXTI_Line1 | EXTI_Line2 | EXTI_Line3;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);
}

void Keypad_Scan(void)
{
    uint8_t row, col;
    static uint8_t last_key = 0xFF; // 上一次按下的键值，初始值为无效值

    // 扫描行
    for (row = 0; row < 4; row++) {
        GPIO_ResetBits(KEYPAD_PORT, ROW_1 << row);
        for (col = 0; col < 4; col++) {
            if (!GPIO_ReadInputDataBit(KEYPAD_PORT, COL_1 << col)) {
                // 检测到按键按下
                uint8_t key = row * 4 + col;
                if (key != last_key) {
                    // 避免重复按键
                    Keypad_Buffer = key;
                    last_key = key;
                }
            }
        }
        GPIO_SetBits(KEYPAD_PORT, ROW_1 << row);
    }
}

// 中断处理函数
void EXTI0_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line0) != RESET) {
        Keypad_Scan();
        EXTI_ClearITPendingBit(EXTI_Line0);
    }
}

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

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

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

在初始化函数中，我们设置了4个行引脚为输入上拉模式，4个列引脚为推挽输出模式。然后我们初始化了4个外部中断线，并将它们映射到4个按键上。在中断处理函数中，我们调用了Keypad_Scan()函数来扫描矩阵键盘，检测是否有按键按下，如果有，将按键值存储在Keypad_Buffer变量中。

在主循环中，我们不需要做任何事情，因为中断会处理按键事件。我们只需要在需要的时候读取Keypad_Buffer变量即可。