Trinket Back-up Sensor

Recently I purchased some Trinket 5V boards from ADAFRUIT. They are a great little board for Learning about electronics and they use the Arduino IDE for programming. With a price tag of $9 in Canada they make a great substitution for the Arduino board and its $30 price tag.

I have put together a great little project using the Trinket and a HC-SR04 distance sensor. All this is a simple back-up sensor. If there is a safe amount of space it displays a green light, as you approach a yellow and then red light are displayed.



Code:


int ECHOPIN = 3;        // Pin to receive echo pulse
int TRIGPIN = 4;       // Pin to send trigger pulse
int LED1 = 0;
int LED2 = 1;
int LED3 = 2;

void setup(){

  pinMode(ECHOPIN, INPUT); // sets echo pin to recive pulse from range finder
  pinMode(TRIGPIN, OUTPUT); //sets trigger pin so range finder can start pulse
  pinMode(LED1,OUTPUT);
  pinMode(LED2,OUTPUT);
  pinMode(LED3,OUTPUT);
}
void loop (){
  digitalWrite(TRIGPIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGPIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGPIN, LOW);
  float distance = pulseIn(ECHOPIN, HIGH);
  distance= distance/58;

  if(distance >= 100){
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
    delay(100);
  }
  if(distance <= 75 && distance >=50 ){

    digitalWrite(LED2, HIGH);
    digitalWrite(LED1, LOW);
    digitalWrite(LED3, LOW);
    delay(100);
  }

  if(distance <= 49.9 && distance >=25 ){

    digitalWrite(LED3, HIGH);
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);

    delay(100);
  }

  if(distance <= 24.5 && distance >=15){

    digitalWrite(LED3, HIGH);
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);

    delay(500);

    digitalWrite(LED3, LOW);
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);

    delay(500);
  }

  if(distance <= 14.5){

    digitalWrite(LED3, HIGH);
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, HIGH);

    delay(100);

    digitalWrite(LED3, LOW);
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);

    delay(100);
  }
}