/* ---------------------------------------------------------------- 
 Arduino Ultrasoninc Sensor HC-SR04
 Ultrasonics based on code by Arbi Abdul Jabbaar
 eSign output by Pete Osborn
 Using Arduino IDE 1.8.13
 Using HC-SR04 Module
 Tested on 15/08/2022 https://wokwi.com/projects/340727728988750418
 ---------------------------------------------------------------- 
*/
long duration; // variable for the duration of sound wave travel
long potVoltage; //votage at potWiper input (fill level)
int distance; // variable for the distance measurement
int fillLevel; // no of segments illuminated on eSign
int maxDistance = 100; //max range in cm ("empty" value)
int minDistance = 3; //min range in cm ("full" value)
int maxSegments = 15; //15 or 9 depending on eSign type
int interval; //eSign segment spacing
int opMode; //selects ultrasonic (=1) or potentiometer (=0) input

//allocate Arduino pin numbers
const byte trigPin = 14; //allocate pin A0/D14 Arduino to pin Trig of HC-SR04
const byte echoPin = 15; // allocate pin A1/D15 Arduino to pin Echo of HC-SR04
const byte potWiper = 16; //allocate pin A2/D14 Arduino to potentiometer wiper
const byte modeSelect = 19; //allocate pin A5/D19 Arduino to input mode switch (1=u/s 0=pot)
const byte eSign1 = 2;//BCD output to high-side driver (lsb)
const byte eSign2 = 4;//BCD output to high-side driver
const byte eSign3 = 6;//BCD output to high-side driver
const byte eSign4 = 8;//BCD output to high-side driver (msb)

void setup() {
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
  pinMode(echoPin, INPUT); // Sets the echoPin as an INPUT
  pinMode(potWiper, INPUT); // Sets the potWiper as an INPUT
  //pinMode(modeSelect, INPUT); // Sets the modeSelect as an INPUT
  pinMode(modeSelect,INPUT_PULLUP); // Sets the modeSelect as an INPUT with pullup resistor
  pinMode(eSign1, OUTPUT);
  pinMode(eSign2, OUTPUT);
  pinMode(eSign3, OUTPUT);
  pinMode(eSign4, OUTPUT);
  digitalWrite(eSign1, LOW);
  digitalWrite(eSign2, LOW);
  digitalWrite(eSign3, LOW);
  digitalWrite(eSign4, LOW);

  Serial.begin(9600); // // Serial Communication is starting with 9600 of baudrate speed
  Serial.println("Ultrasonic Sensor HC-SR04 Test"); 
  Serial.println("with Arduino Nano");


 
}
void loop() {
  opMode=digitalRead(modeSelect);
  if (opMode == 1) { //Ultrasonic sensor mode
  Serial.println(opMode);
  interval = int(maxDistance/maxSegments);
  // Clears the trigPin condition
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Set trigPin HIGH (ACTIVE) for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite (trigPin, LOW);
  // Read echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  // Calculate distance
  distance = duration * 0.034 / 2; // Speed of sound wave divided by 2 (out and back)
  /* Display distance on the Serial Monitor
   Serial.print("Distance reading: ");
   Serial.print(distance);
   Serial.println(" cm");
  */
  if(distance>maxDistance){distance=maxDistance;} //truncate at max range
  /* Serial.println(distance);
   Serial.println(interval);
   */
  fillLevel = int((maxDistance-distance)/interval); //calculate no of segments to be illuminated
  if(fillLevel>maxSegments){fillLevel=maxSegments;} // truncate at min range
 /*
  Serial.print("Fill Level: ");
  Serial.println(fillLevel);
  
  //Print eSign inputs representing fill level
  Serial.print(bitRead(fillLevel,3));
  Serial.print(bitRead(fillLevel,2));
  Serial.print(bitRead(fillLevel,1));
  Serial.println(bitRead(fillLevel,0));
*/

  // Set eSign1..4 outputs to BCD of fillLevel
  if(bitRead(fillLevel,0) == 1) {digitalWrite(eSign1, HIGH);}
  else {digitalWrite(eSign1, LOW);}
  if(bitRead(fillLevel,1) == 1) {digitalWrite(eSign2, HIGH);}
  else {digitalWrite(eSign2, LOW);}
  if(bitRead(fillLevel,2) == 1) {digitalWrite(eSign3, HIGH);}
  else {digitalWrite(eSign3, LOW);}
  if(bitRead(fillLevel,3) == 1) {digitalWrite(eSign4, HIGH);}
  else {digitalWrite(eSign4, LOW);} 
 
   delay(1000); // ensures echo reads are >60ms apart
  }
  else { // Pot input mode
  //Serial.println("Pot Input");
  interval = int(1024/(maxSegments));
  potVoltage = analogRead(potWiper); //Read potWiper position
  Serial.println(potVoltage);
  Serial.print(bitRead(fillLevel,3));
  Serial.print(bitRead(fillLevel,2));
  Serial.print(bitRead(fillLevel,1));
  Serial.println(bitRead(fillLevel,0));
  fillLevel = int((1066-potVoltage)/interval); //calculate no of segments to be illuminated
  
   // Set eSign1..4 outputs to BCD of fillLevel
  if(bitRead(fillLevel,0) == 1) {digitalWrite(eSign1, HIGH);}
  else {digitalWrite(eSign1, LOW);}
  if(bitRead(fillLevel,1) == 1) {digitalWrite(eSign2, HIGH);}
  else {digitalWrite(eSign2, LOW);}
  if(bitRead(fillLevel,2) == 1) {digitalWrite(eSign3, HIGH);}
  else {digitalWrite(eSign3, LOW);}
  if(bitRead(fillLevel,3) == 1) {digitalWrite(eSign4, HIGH);}
  else {digitalWrite(eSign4, LOW);}

  delay(1000);
  }
}