mixly ARDUINO图形编程LCD1602显示的超声波测距程序

代码：

//Arduino超声波测距程序
#include <LiquidCrystal_SoftI2C.h>
#include <SoftI2CMaster.h>
LiquidCrystal_SoftI2C mylcd(0x27,16,2,A5,A4);
volatile int distance;
float checkdistance_2_4() {
  digitalWrite(2, LOW);
  delayMicroseconds(2);
  digitalWrite(2, HIGH);
  delayMicroseconds(10);
  digitalWrite(2, LOW);
  float distance = pulseIn(4, HIGH) / 58.00;
  delay(10);
  return distance;
}
void setup(){
  distance = 0;
  pinMode(2, OUTPUT);
  pinMode(4, INPUT);
  mylcd.init();
  mylcd.backlight();
}
void loop(){
  distance = checkdistance_2_4();
  mylcd.clear();
  mylcd.setCursor(0, 0);
  mylcd.print("distance");
  mylcd.setCursor(0, 1);
  mylcd.print(String(String(distance, DEC)) + String("cm"));
  delay(200);