// Patient Health Monitoring Project - Source Code
// Monitors heart rate and body temperature, alerting and logging to the cloud
 
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <SoftwareSerial.h>
 
// ----- Pin Definitions -----
#define pulsePin A0
#define tempPin 4
#define buzzerPin 8
 
OneWire oneWire(tempPin);
DallasTemperature tempSensor(&oneWire);
LiquidCrystal_I2C lcd(0x27, 16, 2);
SoftwareSerial espSerial(10, 11); // RX, TX for ESP8266
 
// ----- Safe Threshold Configuration -----
const int minSafeBPM = 60;
const int maxSafeBPM = 100;
const float minSafeTemp = 36.0;
const float maxSafeTemp = 37.8;
 
int bpm = 0;
int beatCount = 0;
unsigned long lastBeatTime = 0;
unsigned long windowStart = 0;
 
void setup() {
  pinMode(buzzerPin, OUTPUT);
 
  tempSensor.begin();
  lcd.init();
  lcd.backlight();
  lcd.print("Patient Monitor");
 
  espSerial.begin(9600);
  Serial.begin(9600);
 
  windowStart = millis();
  delay(1500);
  lcd.clear();
}
 
void loop() {
  int sensorValue = analogRead(pulsePin);
 
  // Basic threshold-based heartbeat detection
  if (sensorValue > 550 && (millis() - lastBeatTime) > 300) {
	beatCount++;
	lastBeatTime = millis();
  }
 
  // Calculate BPM every 10 seconds
  if (millis() - windowStart >= 10000) {
	bpm = beatCount * 6;
	beatCount = 0;
	windowStart = millis();
 
|  | tempSensor.requestTemperatures(); |
| --- | --- |
|  | float temperature = tempSensor.getTempCByIndex(0); |
 
|  | updateDisplay(bpm, temperature); |
| --- | --- |
|  | checkVitals(bpm, temperature); |
|  | sendToCloud(bpm, temperature); |
| } |  |
}
 
// Updates the LCD with both heart rate and temperature
void updateDisplay(int currentBPM, float temp) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("HR: " + String(currentBPM) + " BPM");
  lcd.setCursor(0, 1);
  lcd.print("Temp: " + String(temp) + " C");
}