#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Adafruit_BMP085.h>

#define BUZZER_PIN    PA1
#define GREEN_LED_PIN PA4
#define RED_LED_PIN   PA5

// Changed to integers to save flash space!
// 100,000 Pa -> 100 kPa
const int32_t LOW_PRESSURE_KPA  = 50;   
const int32_t HIGH_PRESSURE_KPA = 100; 

LiquidCrystal_I2C lcd(0x27, 16, 2);
Adafruit_BMP085 bmp;

void setup() {
  // REMOVED Serial.begin(115200); -> Saves ~1KB to 2KB of flash!
    
      pinMode(BUZZER_PIN, OUTPUT);
        pinMode(GREEN_LED_PIN, OUTPUT);
          pinMode(RED_LED_PIN, OUTPUT);

            lcd.init();
              lcd.backlight();
                
                  if (!bmp.begin()) {
                      lcd.print("Sensor Error!");
                          while (1); 
                            }
                              lcd.clear();
                              }

                              void loop() {
                                // Read pressure and immediately convert to kPa using integer division
                                  int32_t pressureKPa = bmp.readPressure() / 1000; 
                                    
                                      // Quick integer conversion to PSI (1 kPa is approx 0.145 PSI)
                                        // Multiplying by 145 and dividing by 1000 avoids float math entirely
                                          int32_t pressurePSI = (pressureKPa * 145) / 1000;

                                            // Display Output
                                              lcd.setCursor(0, 0);
                                                lcd.print("Pres: ");
                                                  lcd.print(pressurePSI);
                                                    lcd.print(" PSI   ");

                                                      lcd.setCursor(0, 1);
                                                        if (pressureKPa < LOW_PRESSURE_KPA) {
                                                            lcd.print("ALERT: LOW!!    ");
                                                                digitalWrite(GREEN_LED_PIN, LOW);   
                                                                    digitalWrite(RED_LED_PIN, HIGH);    
                                                                        triggerBeep();                      
                                                                          } 
                                                                            else if (pressureKPa > HIGH_PRESSURE_KPA) {
                                                                                lcd.print("ALERT: HIGH!!   ");
                                                                                    digitalWrite(GREEN_LED_PIN, LOW);   
                                                                                        digitalWrite(RED_LED_PIN, HIGH);    
                                                                                            triggerBeep();                      
                                                                                              } 
                                                                                                else {
                                                                                                    lcd.print("Status: Normal  ");
                                                                                                        digitalWrite(RED_LED_PIN, LOW);     
                                                                                                            digitalWrite(GREEN_LED_PIN, HIGH);  
                                                                                                                digitalWrite(BUZZER_PIN, LOW);      
                                                                                                                    delay(500);                         
                                                                                                                      }
                                                                                                                      }

                                                                                                                      void triggerBeep() {
                                                                                                                        digitalWrite(BUZZER_PIN, HIGH);
                                                                                                                          delay(150);
                                                                                                                            digitalWrite(BUZZER_PIN, LOW);
                                                                                                                              delay(150);
                                                                                                                              }