Final project, hat with ultrasonic sensor and sound warning

As my final project I got an idea about a hat which can talk to the user and guide example a blind guy to the right way and not to crash anything. Or one could solve a maze in complete darkness because the ultrasonic sensor. I first tried to make Arduino say something but it didn't succeed. Then I eased my project and thought maybe same kind of noise what car rear-view cameras make. I found Arduino Tone library. With that I managed to make Arduino Beep! Then I found a broken headset. I ripped the speaker elements out of it and soldered two wires to it. Then I connected the ultrasonic sensor which I got earlier hc-sr04 to Arduino, tested if it works and can measure the distance. I coded it to check if the distance is between three ranges. If the range is shorter than 30 centimeters it will beep very fast and warn the user that you are going to crash. If the distance is between 31 and 60 centimeters it will beep normal speed and it tells that it is safe to turn. If the distance is between 61 and 90 it beeps very slow to warn that you are approaching an obstacle. If the distance is bigger than 90 it stays silent. I think this was very fun project and of course interesting. Thanks to Tero Karvinen i'm now very excited about the Arduino and its possibilities. And then about the project.

I first started to code the project by one piece at a time. First the ultrasonic sensor, then the beep sound and then connected those together. Here i'm currently in test environment.

Next I had to hot glue all the parts to an old peaked cap and solder few wires together.

Then I tested if the parts still work without computer test environment and it didn't. I had to change the speaker connection a little bit and then it worked. Here is the final ultrasonic hat. The battery plus wire was too short but it is just long enough to work.

Testing phase for distance and beep to function correctly together.

And here it is. The final version of my prototype hat for the blind people or drunk people or what ever.

And how I coded it ? Here is the whole code.

Connection like in ultrasonic sensor post and tone post. hc-sr04 vcc to +5v, gnd to gnd, trig to pin 12, echo to pin 13. Speaker element goes to ground and digital pin 8.

//define the pins for ultrasonic sensor here
#define trigPin 12
#define echoPin 13

//setup trig is output and echo is input for the sound. Read serial fastest possible speed
void setup() {
    Serial.begin (115200);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

//below methods for beep speed
void beepFast(){
   // play a note on pin 8 for 200 ms:
  tone(8, 440, 200);
  delay(50);
  // turn off tone function for pin 8:
  noTone(8);
  delay(300);
}

void beepSlow(){
  tone(8, 440, 200);
  delay(500);
  noTone(8);
  delay(300);
}

void beepMedium(){
  tone(8, 440, 200);
  delay(200);
  noTone(8);
  delay(300);
}

//no beep here
void beepNo(){
  noTone(8);
  delay(300);
}

//send a pulse and calculate how long it took to travel
void loop() {
   int duration, distance;
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(1000);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration/2) / 29.1;

//then check the distance and beep if it is in the range
   if (distance >= 200 || distance <= 0){
    Serial.println("Out of range");
  }
  else if (distance >=0 && distance <=30){
    beepFast();
    Serial.print(distance);
    Serial.println(" cm");
  }
else if (distance >=31 && distance <=60) {
  Serial.print(distance);
    Serial.println(" cm");
beepMedium();
}
else if (distance >=61 && distance <= 90){
  Serial.print(distance);
    Serial.println(" cm");
beepSlow();
}
else {
   beepNo();
     Serial.print(distance);
    Serial.println(" cm");
}

}

And the guy behind this blog and random hat project...

Testing phase. She managed to walk to the door from kitchen and back. Succeed.

The project was fun to do and i'm proud that I managed to complete it. One thing more to add my portfolio.