In this project, we will learn how to make an IoT-based ECG monitoring system using an AD8232 ECG sensor and a NodeMCU ESP8266. We will use an IoT platform called Ubidots to watch the ECG waveform/Graph made by the AD8232 Sensor online.

In the last few decades, heart diseases have become a big problem, and many people die because of health problems. So, heart disease is not something to be taken lightly. So, there should be a technology that can keep an eye on the patient's heart rate and how it works. By analyzing or keeping an eye on the ECG signal early on, different types of heart disease can be avoided. This is why I'm showing you this great Internet of Things (IoT) project. In this project, I'll show you how to connect the AD8232 ECG Sensor to the NodeMCU ESP8266 Board and watch the ECG Waveform on the Serial Plotter Screen. In the same way, you can send the ECG waveform over the IoT Cloud platform and monitor the signal online using a PC or a smartphone from anywhere in the world. If you want to watch your heart's activity or behavior, you don't have to stay in the hospital. You can do it online from anywhere. So, it can be said that the Patient Health Monitoring System has made progress. The IoT platform that I am gonna use here is Ubidots. Ubidots is an Internet of Things (IoT) platform that lets innovators and businesses build

prototypes of IoT projects and scale them up to make them. You can send data to the cloud from any device that can connect to the Internet by using the Ubidots platform. Then, you can set up actions and alerts based on your real-time data and use visual tools to get the most out of your data. AD8232 ECG Sensor This sensor is a cheap board that is used to measure the heart's electrical activity. This electrical activity can be charted as an ECG or Electrocardiogram and output as an analog reading. ECGs can be extremely noisy, the AD8232 Single Lead Heart Rate Monitor acts as an op-amp to help obtain a clear signal from the PR and QT Intervals easily. The AD8232 is a built-in signal conditioning block that can be used to measure ECG and other biopotentials. It is made to find, boost, and filter small biopotential signals even when there is a lot of noise, like when the electrodes are moved or placed far away. The AD8232 module breaks out nine connections from the IC that you can solder pins, wires, or other connectors to. This monitor can be used with an Arduino or other development board through its SDN, LO+, LO-, OUTPUT, 3.3V, and GND pins. There are also RA (Right Arm), LA (Left

Arm), and RL (Right Leg) pins on this board so you can attach and use your own custom sensors. There is also an LED indicator light that pulses to the beat of your heart. Note: This product is NOT a medical device, and it is not meant to be used as one or as a part of one. It is also not meant to be used to diagnose or treat any health problems.

NodeMCU (ESP8266-12E Board) ECG Sensor (AD8232 ECG Sensor Kit) Data Cable (5V Micro USB Data Cable) USB Adapter - 5V Breadboard Circuit Diagram: Interfacing AD8232 ECG Sensor with NodeMCU ESP8266 Here is a diagram of how to connect the NodeMCU ESP8266 to the AD8232 ECG sensor. AD8232 Breakout Board has six pins. SDN is not linked together.

Connect the OUTPUT to Nodemcu's analog A0. Connect the LO+ and LO- wires to NodeMCU's D5 and D6. Give the AD8232 kit 3.3V VCC and connect its GND to the GND on the kit. ECG Leads/Electrode Placement It is recommended to snap the sensor pads on the leads before application to the body. The better the reading, the closer the pads are to the heart. The cables are color-coded to help identify proper placement. Red: RA (Right Arm) Yellow: LA (Left Arm) Green: RL (Right Leg) We connected an ESP8266 with an AD8232 to a patient chest, or you can just put it in your chest, as shown in the figure picture. Result & Observations

Open the Serial Monitor and set the Buad Rate to 9600 once the code is uploaded. As a visualization effect on Serial Monitor, the ECG waveform can be seen in the next image. IoT based ECG Monitoring with AD8232 ECG Sensor & ESP8266 With the code shown above, you can see the ECG waveform on the Serial Plotter Screen. Now, though, we want to be able to see the ECG waveform from anywhere in the world. So, I won't have to send the signal to any IoT platform for that. I did that with Ubidots. With Ubidots, you can send information to the cloud from any device that can connect to the Internet. Results & Observations After you upload the code, you can open the serial Monitor. If the module is connected to WiFi and Ubidot's token is valid, the Serial Monitor will show the following lines.

You can now go to the Ubidots dashboard and watch the waveform get posted on Ubidots. Due to a small amount of delay, the waveform may not look exactly like the one above. But it's enough to show something simple. In the near future, the device can be made in a better way.