Race Photogate

/* PhototransistorVoltage Solar Car Timer by Nelson Farrier
 * Power each phototransistor with 5v and GND
 * Connect the 2 phototransistors yellow wires 
 *       into A0 & A1 to detect start and stop of car.
 * Use 4 pins (below) to indicate laser alignment
 * Use 4 analog pins (A0-A3) for detecting photo transistor voltage
 */
#include <LiquidCrystal_I2C.h>  // Must be downloaded separtely & put in your Arduino's libraries folder

/*----- LCD Pin configuration-----*/
//GND - GND
//VCC - 5V
//SDA - ANALOG Pin 4
//SCL - ANALOG pin 5

LiquidCrystal_I2C lcd(0x27, 16, 2);

const boolean testing = false;

const int align1Pin = 8;  // pin to show laser is on 1st mark
const int align2Pin = 9;  // pin to show laser is on 2nd mark
const int align3Pin = 10;  // pin to show laser is on 1st mark
const int align4Pin = 11;  // pin to show laser is on 2nd mark

const int interval = 10;  // accuracy of timer in milliseconds
float threshold = 0.75;    // voltage where phototransistor shows car is in the way
float v1, v2, v3, v4, timer1Count, timer2Count;
boolean A, B, C, D, doneLtiming, doneRtiming, triggeredL, triggeredR, overLmtL, overLmtR, statusLCDshown, statusRshown, statusLshown, finishLshown, finishRshown;  // A & C on one lane, B & D on other
int count=0, msg = 0;
char inSerial[15];
const int StartL = 1;
const int StartR = 2;
const int FinishL = 3;
const int FinishR = 4;
const int leftLane = 0;
const int rightLane = 1;
const float overtime = 60000; // 1 minute

// bluetooth codes
const int Reset = 9;
const int Other = 10;

void setup()                                 // Built-in initialization block
{
  Serial.begin(9600);                        // Set data rate to 9600 bps
  pinMode(align1Pin,OUTPUT);
  pinMode(align2Pin,OUTPUT);
  pinMode(align3Pin,OUTPUT);
  pinMode(align4Pin,OUTPUT);
  Serial.println("!Waiting to connect to Bluetooth...");      
  lcd.begin();
  lcd.clear();
  lcd.setCursor(16,2);   
  lcd.backlight();
  lcd.setCursor(0 ,0); 
}

void loop() {  
  lcd.setCursor(16,2);   // initialize the lcd for 16 chars 2 lines, turn on backlight
  lcd.backlight();

  A = B = C = D = doneLtiming = doneRtiming= triggeredL = triggeredR = overLmtL = overLmtR = statusLCDshown = false;  // A & C on one lane, B & D on other
  finishLshown = finishRshown = statusLshown = statusRshown = false;
  boolean wait = true;
  waitForAlignment();
  timer1Count = 0;
  timer2Count = 0;
  count = 0;
  
  delay(1000);
  Serial.print("!Ready...");       
  lcd.clear();
  lcd.setCursor(0 ,0); //Start at character 4 on line 0
  lcd.print("Ready...");
  delay(1000);
  
  Serial.println("Set...");
  lcd.print("Set...");
  
  while ((!doneLtiming) || (!doneRtiming)) {
    if (triggeredL || triggeredR) {
      if (!statusLCDshown) {
      lcd.setCursor(0 ,1);
      lcd.print("Race Started!");
      if (testing) { 
        Serial.println(A); 
        Serial.println(B); 
        Serial.println(C); 
        Serial.println(D); 
        }
      statusLCDshown = true;
      }
      if ((triggeredL) && (!statusLshown)) {
        Serial.println("Race started in left lane");
        statusLshown = true;
      }
      if ((triggeredR) && (!statusRshown)) {
        Serial.println("Race started in right lane");
        statusRshown = true;
      }
      
    }     

    if (triggeredL && !doneLtiming) {             //  add interval to timer because L lane has started 
      timer1Count = timer1Count+interval; 
    }
    if (triggeredR && !doneRtiming) {             //  add interval to timer because R lane has started 
      timer2Count = timer2Count+interval; 
    }
    if (timer1Count > overtime) {
      doneLtiming = overLmtL = true;
    }
    if (timer2Count > overtime) {
      doneRtiming = overLmtR = true;
    }
    v1 = volts(A0);                    
    v2 = volts(A1);                    
    v3 = volts(A2);                    
    v4 = volts(A3);                    
    if (v1 < threshold) { digitalWrite(align1Pin, LOW); }   // turn off (and leave off) LED's as they are triggered
    if (v2 < threshold) { digitalWrite(align2Pin, LOW); }
    if (v3 < threshold) { digitalWrite(align3Pin, LOW); }
    if (v4 < threshold) { digitalWrite(align4Pin, LOW); }

    if (!triggeredL) {
      triggeredL = (v1 < threshold) || (v3 < threshold);       // initial trigger L (front or back)
      A = (v1 < threshold);
      C = (v3 < threshold);
    }
    else {
      if (A) {                                                 // final trigger L (front or back)
        if (v3 < threshold) { 
          doneLtiming = true; 
          if (!finishLshown) {
            Serial.println("Left lane finished"); 
            showLaneTime(leftLane,timer1Count,overLmtL);
            finishLshown = true; 
          }  
        }
       }
      if (C) {
        if (v1 < threshold) { 
          doneLtiming = true; 
          if (!finishLshown) {
            Serial.println("Left lane finished"); 
            showLaneTime(leftLane,timer1Count,overLmtL);
            finishLshown = true;
          }   
        }
      }
    }
    
    if (!triggeredR) {
      triggeredR = (v2 < threshold) || (v4 < threshold);        // initial trigger R (front or back)
      B = (v2 < threshold);
      D = (v4 < threshold);
    }
    else {
      if (B) {                                                  // final trigger R (front or back)
        if (v4 < threshold) { 
          doneRtiming = true; 
          if (!finishRshown) {
            Serial.println("Right lane finished"); 
            showLaneTime(rightLane,timer2Count,overLmtR);
            finishRshown = true;
          }   
        }
        }
      if (D) {
        if (v2 < threshold) { 
          doneRtiming = true; 
          if (!finishRshown) {
            Serial.println("Right lane finished"); 
            showLaneTime(rightLane,timer2Count,overLmtR);
            finishRshown = true;
          }   
        }
        }
      }

    delay(interval);                 // Delay for defined time
  }

  // end timer count and display results
  flashScreen();
  delay(80);
  if (testing) {
    Serial.print(triggeredL);
    Serial.print(triggeredR);
    Serial.print(doneLtiming);
    Serial.println(doneRtiming);
  }
  Serial.println("!Race Complete");  
  showLaneTime(leftLane,timer1Count,overLmtL);
  showLaneTime(rightLane,timer2Count,overLmtR);
  Serial.println("");                  // print blank line
       
//loop until bluetooth "Reset" sent or rebooted


while (wait) {
  int i=0;
  int m=0;
  delay(500);
  if (Serial.available() > 0) {
  while (Serial.available() > 0) {
  inSerial[i]=Serial.read();
  i++;
  }
  inSerial[i]='\0';
  msg = Check_Protocol(inSerial);
  wait = (! msg == Reset);
  if (msg == Reset) {
    flashLED(8);
  }
  }
}
}

//-----------------------------------------

void showLaneTime(int lane, float timerCount, boolean overLmt) {
if (lane == leftLane) {
  Serial.print("Left Lane Time:  ");       
  lcd.setCursor(0,0);
  lcd.print("L Time=");       
} else {
  Serial.print("Right Lane Time: ");       
  lcd.setCursor(0,1);
  lcd.print("R Time=");       

}
  if (!overLmt) {
    Serial.print(timerCount/1000);       // Display timerCount in #.## format
    Serial.println(" sec");             
    lcd.print(timerCount/1000);       
    lcd.println(" sec  ");             
  }
  else {
    Serial.print("past limit");
    lcd.println(" past lmt  ");             
  }
}

                                        
float volts(int adPin)                       // Measures volts at adPin
{                                            // Returns floating point voltage
 return float(analogRead(adPin)) * 5.0 / 1024.0;
}    

void flashScreen() {
    for(int i = 0; i< 3; i++)
  {
    lcd.backlight();
    delay(150);
    lcd.noBacklight();
    delay(150);
  }
  lcd.backlight(); // finish with backlight on  
}

int Check_Protocol(char inStr[]){
  int i=0;
  int m=0;
  uint32_t c=0;  // color of bounce
  
  Serial.println(inStr);
  if (!strcmp(inStr,"Reset")){    //Reset system  
    //Serial.println("Reset");
    return Reset;
    for(m=0;m<11;m++){
      inStr[m]=0;}
      i=0;
    }

  if (!strcmp(inStr,"other")){     
    Serial.println("Other");
    return Other;
    for(m=0;m<11;m++){
      inStr[m]=0;}
    i=0;
    }
  else{
    for(m=0;m<11;m++){
      inStr[m]=0;}
  i=0;
  }
}

void flashLED(int pinNum) {
    digitalWrite(pinNum, LOW);
    delay(200);
    digitalWrite(pinNum, HIGH);
    delay(200);
    digitalWrite(pinNum, LOW);
    delay(200);
    digitalWrite(pinNum, HIGH);
    delay(200);
    digitalWrite(pinNum, LOW);
    delay(200);
    digitalWrite(pinNum, HIGH);
    delay(200);
    digitalWrite(pinNum, LOW);
}

void  waitForAlignment() {
  boolean Start1 = false;
  boolean Start2 = false;
  boolean Finish1 = true;
  boolean Finish2 = true;
  Serial.println("!Checking Laser Alignment...");       // wait for either phototransistor to be dimmed
  lcd.clear();
  lcd.setCursor(0 ,0);     //Start at character 1 on line 0
  lcd.print("Checking Laser");
  lcd.setCursor(0 ,1);     //Start at character 1 on line 1
  lcd.print("Alignment...");
  delay(2000);
  boolean done = false;
  lcd.clear();
  while (!done) {
    v1 = volts(A0);
    digitalWrite(align1Pin, !(v1 < threshold));
    Start1 = !(v1 < threshold);
    alignmentCheck(Start1,StartL,v1);
    if (testing) {
      Serial.print( " ");                    
      Serial.print(v1);                  // Display measured A0 volts
      Serial.println(" volts ");       
    }

    v2 = volts(A1);
    digitalWrite(align2Pin, !(v2 < threshold));
    Start2 = !(v2 < threshold);
    alignmentCheck(Start2,StartR,v2);
    if (testing) {
      Serial.print( " ");                    
      Serial.print(v2);                  // Display measured A1 volts
      Serial.println(" volts ");       
    }

    v3 = volts(A2);
    digitalWrite(align3Pin, !(v3 < threshold));
    Finish1 = !(v3 < threshold);
    alignmentCheck(Finish1,FinishL,v3);
    if (testing) {
      Serial.print( " ");                     
      Serial.print(v3);                 // Display measured A2 volts
      Serial.println(" volts ");       
    }

    v4 = volts(A3);
    digitalWrite(align4Pin, !(v4 < threshold));
    Finish2 = !(v4 < threshold);
    alignmentCheck(Finish2,FinishR,v4);
    if (testing) {
      Serial.print( " ");                     
      Serial.print(v4);                 // Display measured A3 volts
      Serial.println(" volts ");        
    }
    
    Serial.println("  ");       
    delay(500);                               // Delay for 0.5 seconds
    done = (Start1 && Start2 && Finish1 && Finish2);
  }
  Serial.println("!Lasers Aligned");       // wait for either phototransistor to be dimmed
  lcd.clear();
  lcd.setCursor(0 ,0); //Start at character 4 on line 0
  lcd.print("Lasers Aligned");
  delay(2000);
}

void alignmentCheck(boolean aligned, int section, float v) {
    String fullTextOut, smTextOut;
    if (section == StartL) { 
      fullTextOut = "Left Start"; 
      smTextOut = "A"; 
      lcd.setCursor(0, 0);
      }
    if (section == StartR) {
      fullTextOut = "Right Start"; 
      smTextOut = "B"; 
      lcd.setCursor(8, 0);
      }
    if (section == FinishL) { 
      fullTextOut = "Left Finish"; 
      smTextOut = "C"; 
      lcd.setCursor(0, 1);
     }
    if (section == FinishR) { 
      fullTextOut = "Right Finish"; 
      smTextOut = "D"; 
      lcd.setCursor(8, 1);
      }
    if (aligned) {
      Serial.println(fullTextOut+" Aligned");                  
      lcd.print(smTextOut+"=OK   ");                            
    }
    else {
      Serial.print(fullTextOut+"=");                     // Display "Ax = "
      lcd.print(smTextOut+"=");
      Serial.print(v);                  // Display measured Ax volts
      Serial.println(" volts ");        // Display " volts" & newline
      lcd.print(v);                     // Display measured Ax volts
      lcd.print("v ");                  // Display " volts" & newline
    }
}