Heart Rate Monitor AD8232 Interface Arduino

The AD8232 from Analog Devices is a dedicated single lead heart rate monitor front end integrated circuit. The AD8232 is an integrated signal conditioning block for ECG and other biopotential measurement applications. It is designed to extract, amplify, and filter small biopotential signals in the presence of noisy conditions, such as those created by motion or remote electrode placement.

This design allows for an ultralow power analog-to-digital converter (ADC) or an embedded microcontroller to acquire the output signal easily.

What Is ECG

Electrocardiography (ECG or EKG) is the method of recording the electrical activity of heart over a period of time using the electrodes placed on the skin.

Heart Monitor AD8232 Board

The simple and easy to use breakout board for heart rate monitoring from Sparkfun. This board measures electrical activity of heart through the Electrode pads placed on the skin. By Interfacing this board with Arduino we can get ECG graph through Processing IDE window.

Pin Configuration

connections :

GND Ground GND

3.3v 3.3v Power Supply3.3v

OUTPUT OutputSignal A0

LO- Leads-off Detect –11

LO+ Leads-off Detect +10

SDN Shutdown Not used

Electrode Pads Cable ColorSignal

BlackRA (Right Arm)

BlueLA (Left Arm)

RedRL (Right Leg)

Circuit Diagram

#Heart Rate Monitor AD8232 Interface arduino

components needed

arduino uno

AD8232 sensor

3 electrodes

wires

Arduino Code

/****************************************************************************** Heart_Rate_Display.inoDemo Program for AD8232 Heart Rate sensor. Casey Kuhns @ SparkFun Electronics 6/27/2014 https://github.com/sparkfun/AD8232_Heart_Rate_Monitor ******************************************************************************/ void setup() { // initialize the serial communication: Serial.begin(9600); pinMode(10, INPUT); // Setup for leads off detection LO + pinMode(11, INPUT); // Setup for leads off detection LO - } void loop() { if((digitalRead(10) == 1)||(digitalRead(11) == 1)){ Serial.println('!'); } else{ // send the value of analog input 0: Serial.println(analogRead(A0)); } //Wait for a bit to keep serial data from saturating delay(1); }

Processing Code

/****************************************************************************** Heart_Rate_Display.inoDemo Program for AD8232 Heart Rate sensor. Casey Kuhns @ SparkFun Electronics 6/27/2014 https://github.com/sparkfun/AD8232_Heart_Rate_Monitor ******************************************************************************/ import processing.serial.*; Serial myPort; // The serial port int xPos = 1; // horizontal position of the graph float height_old = 0; float height_new = 0; float inByte = 0; void setup () { // set the window size: size(1000, 400); // List all the available serial ports println(Serial.list()); // Open whatever port is the one you're using. myPort = new Serial(this, Serial.list()[0], 9600); // don't generate a serialEvent() unless you get a newline character: myPort.bufferUntil('\n'); // set inital background: background(0xff); } void draw () { // everything happens in the serialEvent() } void serialEvent (Serial myPort) { // get the ASCII string: String inString = myPort.readStringUntil('\n'); if (inString != null) { // trim off any whitespace: inString = trim(inString); // If leads off detection is true notify with blue line if (inString.equals("!")) { stroke(0, 0, 0xff); //Set stroke to blue ( R, G, B) inByte = 512; // middle of the ADC range (Flat Line) } // If the data is good let it through else { stroke(0xff, 0, 0); //Set stroke to red ( R, G, B) inByte = float(inString); } //Map and draw the line for new data point inByte = map(inByte, 0, 1023, 0, height); height_new = height - inByte; line(xPos - 1, height_old, xPos, height_new); height_old = height_new; // at the edge of the screen, go back to the beginning: if (xPos >= width) { xPos = 0; background(0xff); } else { // increment the horizontal position: xPos++; } } }