一、按键原理图
蓝色框中是与对应按键相连接的引脚，红色框中是按键。
将PB0、PB1、PB2、PA0这四个引脚设置为上拉输入模式，即
按键没有按下时，输入得到高电平，(按键断开(未被按下),PB0只会接收来自VDD的高电平)。
按键按下时， 输入得到低电平，(按键闭合(被按下),PB0接收来自GND的低电平)。
二、按键扫描函数
三、LCD 显示
fun.c
cpp
#include "headfile.h"
int count = 0;
void led_show(uint8_t led, uint8_t mode)
{
HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);
if(mode)
{
HAL_GPIO_WritePin(GPIOC,GPIO_PIN_8 << (led-1),GPIO_PIN_RESET);
}
else
{
HAL_GPIO_WritePin(GPIOC,GPIO_PIN_8 << (led-1),GPIO_PIN_SET);
}
HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);
}
uint8_t B1_state; //B1当前状态
uint8_t B1_last_state; //B1上次的状态
uint8_t B2_state;
uint8_t B2_last_state;
void key_scan()
{
B1_state = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_0);
B2_state = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_1);
if(B1_state == 0 && B1_last_state == 1)//按键B1按下
{
count++;
}
if(B2_state == 0 && B2_last_state == 1)//按键B1按下
{
count--;
}
B1_last_state = B1_state;
B2_last_state = B2_state;
}
char date[20]; //因为这块lcd屏幕最多只能展示20个字符
void lcd_show()
{
sprintf(date, " test ");
LCD_DisplayStringLine(Line0, (uint8_t *)date);
sprintf(date, " count: %d ", count);
LCD_DisplayStringLine(Line3, (uint8_t *)date);
}四、解决led和lcd引脚冲突问题
解决方法
五、定时器
一般用通用定时器
1s中断一次
led闪烁
长按键和短按键
定时器的三个寄存器
长按的意思是：当按键按下时，CNT = 0，（在未松开按键的这段时间里面，CNT的值会一直增加） 过来一段时间后，判断CNT是否大于10000，自己定义如果大于，就意味着按键是长按。
lcd高亮显示（fun.c）
cpp
#include "headfile.h"
int count = 0; //计数
uint8_t led_mode = 0; //mode为1，灯亮；mode为2，灯灭
uint8_t lcd_highshow = 0; //lcd_highshow行进行高亮显示
void led_show(uint8_t led, uint8_t mode)
{
HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);
if(mode)
{
HAL_GPIO_WritePin(GPIOC,GPIO_PIN_8 << (led-1),GPIO_PIN_RESET);
}
else
{
HAL_GPIO_WritePin(GPIOC,GPIO_PIN_8 << (led-1),GPIO_PIN_SET);
}
HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);
}
uint8_t B1_state; //B1当前状态
uint8_t B1_last_state = 1; //B1上次的状态
uint8_t B2_state;
uint8_t B2_last_state = 1;
uint8_t B3_state;
uint8_t B3_last_state = 1;
uint8_t B4_state;
uint8_t B4_last_state = 1;
void key_scan()
{
B1_state = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_0);
B2_state = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_1);
B3_state = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_2);
B4_state = HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0);
//按键B1
if(B1_state == 0 && B1_last_state == 1)//按键B1按下
{
TIM3->CNT = 0; //计数器清零
}
else if(B1_state == 0 && B1_last_state == 0)//按键B1一直按着
{
if(TIM3->CNT >= 10000)//按键B1长按1s
{
count++;
}
}
else if(B1_state == 1 && B1_last_state == 0) //按键B1松开
{
if(TIM3->CNT < 10000) //按键B1短按
{
count += 2;
}
}
//按键B2
if(B2_state == 0 && B2_last_state == 1)//按键B1按下
{
TIM3->CNT = 0; //计数器清零
}
else if(B2_state == 0 && B2_last_state == 0)//按键B1一直按着
{
if(TIM3->CNT >= 10000)//按键B1长按1s
{
count--;
}
}
else if(B2_state == 1 && B2_last_state == 0) //按键B1松开
{
if(TIM3->CNT < 10000) //按键B1短按
{
count -= 2;
}
}
//按键B3
if(B3_state == 0 && B3_last_state == 1)//按键B1按下
{
led_show(2, 1);
}
//按键B4
if(B4_state == 0 && B4_last_state == 1)//按键B1按下
{
lcd_highshow++;
lcd_highshow %= 3; //lcd_highshow的取值范围为0、1、2
led_show(2, 0);
}
B1_last_state = B1_state;
B2_last_state = B2_state;
B3_last_state = B3_state;
B4_last_state = B4_state;
}
char date[20]; //因为这块lcd屏幕最多只能展示20个字符
void lcd_show()
{
sprintf(date, " test ");
LCD_DisplayStringLine(Line0, (uint8_t *)date);
if(lcd_highshow == 0)
{
LCD_SetBackColor(Yellow);//设置文字背景色
sprintf(date, " count: %d ", count);
LCD_DisplayStringLine(Line3, (uint8_t *)date);
LCD_SetBackColor(Black);
sprintf(date, " para4 ");
LCD_DisplayStringLine(Line4, (uint8_t *)date);
sprintf(date, " para5 ");
LCD_DisplayStringLine(Line5, (uint8_t *)date);
sprintf(date, " para8 ");
LCD_DisplayStringLine(Line8, (uint8_t *)date);
}
else if(lcd_highshow == 1)
{
sprintf(date, " count: %d ", count);
LCD_DisplayStringLine(Line3, (uint8_t *)date);
LCD_SetBackColor(Yellow);
sprintf(date, " para4 ");
LCD_DisplayStringLine(Line4, (uint8_t *)date);
LCD_SetBackColor(Black);
sprintf(date, " para5 ");
LCD_DisplayStringLine(Line5, (uint8_t *)date);
sprintf(date, " para9 ");
LCD_DisplayStringLine(Line9, (uint8_t *)date);
}
else if(lcd_highshow == 2)
{
sprintf(date, " count: %d ", count);
LCD_DisplayStringLine(Line3, (uint8_t *)date);
sprintf(date, " para4 ");
LCD_DisplayStringLine(Line4, (uint8_t *)date);
LCD_SetBackColor(Yellow);
sprintf(date, " para5 ");
LCD_DisplayStringLine(Line5, (uint8_t *)date);
LCD_SetBackColor(Black);
sprintf(date, "12345678901234567890");
LCD_DisplayStringLine(Line9, (uint8_t *)date);
}
led_show(1, led_mode);//放在次处，是为了避免lcd和led引脚冲突
}
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) //中断回调函数（时间到了，就会触发该函数）
{
if(htim->Instance == TIM2) //判断定时器中断来源是定时器2吗
{
led_mode++;
led_mode = led_mode % 2;
}
}