Qduino

#define trigPin 1
#define echoPin 0

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  Serial.begin(9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(10, OUTPUT);
  pinMode(2, OUTPUT);
  digitalWrite(2, LOW);
  pinMode(4, INPUT_PULLUP);
}

// the loop function runs over and over again forever
void loop() {
  bool HIGH_LOW = digitalRead(4);
  digitalWrite(10, HIGH_LOW);
  digitalWrite(2, !HIGH_LOW);
  ping();
}

void ping() {
  long duration, distance;
  digitalWrite(trigPin, LOW);  // Added this line
  delayMicroseconds(2); // Added this line
  digitalWrite(trigPin, HIGH);
//  delayMicroseconds(1000); - Removed this line
  delayMicroseconds(10); // Added this line
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration/2) / 29.1;
  Serial.println(distance);
}

void blink() {
    digitalWrite(10, HIGH);   // turn the LED on (HIGH is the voltage level)
  digitalWrite(2, HIGH);
  delay(100);
  digitalWrite(2, LOW);
  delay(900);                       // wait for a second
  digitalWrite(10, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);          
}

• https://cdn.sparkfun.com/datasheets/Dev/Arduino/Boards/Qduino_Mini_v14.pdf
• https://www.sparkfun.com/products/13614
• https://www.hackster.io/team-qtechknow/qduino-mini-quickstart-guide-8b2d68