#define TRIG D4
#define ECHO D5
#define LED2 D8
#define LED1 D11
long duration;
float distance;
void setup() {
  pinMode(TRIG,OUTPUT);
  pinMode (ECHO,INPUT);
  pinMode (LED1,OUTPUT);
  pinMode (LED2,OUTPUT);
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, STM32!");
}

void loop() {
 digitalWrite(TRIG,LOW);
 delayMicroseconds(2);
 digitalWrite(TRIG,HIGH);
 delayMicroseconds(10);
 digitalWrite(TRIG,LOW);
 duration=pulseIn(ECHO,HIGH);
 distance=(duration*0.0343)/2;
 Serial.println(distance);
}