int8_t  led_pin=13;int8_t  led2_pin=12;
void setup() {// put your setup code here, to run once:pinMode(led_pin, INPUT);//输入pinMode(led2_pin, OUTPUT);//输出
}void loop() {// put your main code here, to run repeatedly:if(digitalRead(led_pin)==1){//digitalRead(引脚号)digitalWrite(led2_pin, LOW);}if(digitalRead(led_pin)!=1){digitalWrite(led2_pin, HIGH);}}

digitalRead(引脚号)   //检测引脚电平   高为1   低为   0       或  HIGH //   1    //高 LOW  // 0//低

按键结构

去抖动

         

#define DEBOUNCE_DELAY 20 // 延时等待的时间（单位：毫秒）bool debounce(int pin) {if (digitalRead(pin) == HIGH) {delay(DEBOUNCE_DELAY); // 等待if (digitalRead(pin) == HIGH) {return true; // 按键稳定为高电平}}return false; // 按键不是稳定的高电平
}