ECG Front-End Design: Low-Noise Amplification & Signal Acquisition

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET    -1 // Share reset pin with Arduino
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

const int ecgPin = A0;   // Analog input connection from front-end
int xPos = 0;            // Horizontal chart coordinate
int lastY = 32;          // Track previous sample height

void setup() {
  Serial.begin(115200);
  
  // Initialize SSD1306 display panel over I2C at address 0x3C
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("OLED Allocation Failed"));
    for(;;);
  }
  
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(15, 24);
  display.println(F("ECG FRONT-END READY"));
  display.display();
  delay(1500);
  display.clearDisplay();
}

void loop() {
  // Read raw biometric signal from data pipeline
  int rawAnalog = analogRead(ecgPin); 
  
  // Map the 10-bit input value (0-1023) down into OLED screen height limits (0-63)
  int yPos = map(rawAnalog, 0, 1023, SCREEN_HEIGHT - 5, 5);
  
  // Render continuous signal tracking bars dynamically
  if (xPos > 0) {
    display.drawLine(xPos - 1, lastY, xPos, yPos, SSD1306_WHITE);
  }
  
  lastY = yPos;
  xPos++;
  
  // Sweep screen edge constraint loop reset
  if (xPos >= SCREEN_WIDTH) {
    xPos = 0;
    display.clearDisplay();
  }
  
  display.display();
  delay(10); // Enforces proper sampling constraints
}

Technical Specifications