Working & Interfacing

IoT (Internet of Things)

The Internet of Things, or which is also known as IoT, that implies the billions of physical devices in a daily life that is around the world & that are related with the web. It's possible to turn anything, from something as meager as a pill to something, into a bit of the IoT. Now the most of the devices are controlled with the help of internet. Most of devices everyone can controlled with home automation. Light bulb usually switch on and off with help of IoT. IoT is related to the billions of physical devices that are present around the world. Working of IoT is very simple most of the devices are collect data from the sensors and transmit the data to the other devices after that all sensor data are stored and analyzing of data is started.

Implementation of internet of things based With sensors

All Sensors are used for collecting the information from the human body. After collecting the data from human body that data directly send to the server (IoT cloud). Monitoring system includes the following parameters for the transmission of data on cloud.

Sensor module
Controller module
Wi-Fi module
Power module

Sensor Module :- Sensors Module includes AD8232 (ECG Sensor), DHT11 ( Temperature & Humidity Sensor) and MAX30100 (Pulse & Oximeter Sensor) Sensor module is very important part place in ECG monitoring because with the help of this module we can collect the log values (data) from the human body and that sensor usually named as ad 8232 ECG sensor module. This sensor can also detect a weak ECG signal. We know that a very typical frequency should be lies between 0.5 Hz to 100 Hz of the ECG signal. For the removal of unwanted noise in a system we will use bandpass filter in ECG signal. After that pure signal is transmitted with the help of signal amplifier and in the last finally with the help of power module these sensors can operate on 3.3 v.

Controller Module :-In a case of ECG monitoring which used ESP 32 controller to control the ECG sensor. ESP 32 is generally a Wi-Fi module and that by the module is used to transmit the information or data on server and also on cloud. ESP 32 is connected with ECG sensor AD8232 module.

Power Module :- Power module generally used for provide the energy to controller and also to sensor.

MQTT

MQTT is a message Quing Telememtry transport. MQTT is a protocol. MQTT is also known as the light weight public device and that can also subscribe the system in which we can work as both publish and receive a message as a client. MQTT is a simple messaging protocol with low bandwidth. MQTT is a perfect solution of IoT based platforms because by using of MQTT we can send the data to cloud.

MQTT is also responsible to send commands to the server to control outputs and also read,published data from the sensor nodes.

MQTT basic Concept

MQTT consists of the four concepts

Publish/Subscribe
Messages
Topic
Broker

First step of MQTT that publish and subscribe system. In publish and subscribe system firstly a device that can publish a message to the server it can either be subscribed to a particular topic in order to receive message. In a second concept message contains information that you want to exchange between the your device and the server. It can either be a command or data. The third main concept is related to the topics.

The topics are the very important concept of the MQTT topics for specifies the interest for the incoming message and how to define where we want to publish the message. Topics are always described as strings that is separated by the forward slash. Each slash in a given topic indicates as the topic level. Topics are also case sensitive. The final concept of MQTT is a broker.

The working of broker in MQTT is to receive the message and filtering the message. It can also publish the message to the subscribe client. There are so many brokers can be used but for the home automation we always use mosquito broker that can be installed with the help of raspberry pi but alternative you can easily use cloud MQTT broker.

Interfacing of LCD with arduino and DHT 11

Interfacing of DHT11 with arduino is simple. Arduino has so many digital pins & it can easily interface with LCD. DHT 11 has three pins. On the other hand arduino has 16 pins but we will use only the 12 pins. Firstly LCD pins will connected to you arduino and then the pins of DHT 11 will also connected to arduino.

Auduino can be operates on 5 volts. DHT 11 can stick to human body and it will show the temperature and humidity on LCD. It is very easy to operate and simple to use. Temperature will appear on LCD in a form of Celsius.

Interfacing of ESP 32 with ad8232 module

The first step is to transmit the ECG signal to the cloud is to interface both ESP 32 and Ad8232 together. For the interfacing of ESP 32 we will use 3 pins of ESP 32 to control the ECG sensor. These pins are 3 volt, ground and output. The output signal is a analogue signal. After connecting the three pins, now our next step is to connect the ECG patches to 8232 ECG module. In ECG sensor there are only three types of electrodes are present these electrodes have the three different colours that are yellow, green and red. Mainly two electrodes yellow and green electrodes are used for capturing the ECG signal.

ESP32 with AD8232

Black pin = 3V

Brown Pin = Ground

Output= Green

Yellow electrode can be placed on human chest while other green electrode can be placed on the right hand in human body. After placing then both electrodes for human body the ECG sensor will collect the data from the human body and send it to the ESP 32. Now ESP 32 is connected with Wi-Fi and it can easily transmit the data to the IOT cloud. Now the ECG data will appear live on the server.

Interfacing of DHT11 with ESP 32

Now our next step is to interface DHT11 to ESP 32. DHT 11 has three pins that are voltage, ground and data. D15 data pin is used as output pain for or humidity and temperature. With the help of DHT 11 we can check the human body temperature. This DHT 11 will stick to human body and that will record the human temperature. The voltage pin of DHT 11 will directly connect to the ESP 32 voltage while the ground pin of DHT 11 will connect to the ground of ESP 32. And for output of DHT 11 it will directly connect to the digital pin of ESP 32.

ESP32 with DHT11

Black pin = 3V

Brown Pin = Ground

Output= Green

ESP 32 collect output from DHT 11 of the body temperature and it will directly send to the server. From the server every user can access this data. Mainly the temperature can be accessed in Celsius on server. ESP 32 can operate on the 5 volts.

Interfacing of ESP 32 with Max 30100

Max30100 is a pulse and oximeter capturing system. The ground of Max 30100 is connected to the ground of ESP 32. Vin of Max 30100 is connected to the 3 volt of ESP 32. ESP 32 has the many digital pins & it has also the capability of SCL and SDA system. SCL pin of Max 30100 is connected to the D21 21 pin of ESP 32 while SDA pin of Max 30100 is connected to the D22 pin of ESP 32.

ESP32 with MAX30100

Black pin = 3V

Brown Pin = Ground

SCL = D21

SDA = D22