A patient's temperature remote control system based on NODEMCU ESP8266

. With the prompt development in wireless communication, in addition to the evolution of wireless patient monitoring system, and to reduce the death of a big number of patients who endear as a result of heart failure or sudden high temperature in children. This paper proposed a sophisticated method of observation human body parameters like temperature measurements with employ at NodeMcu ESP8266 unit in the Internet of Things (IoT). This prototype is based on NodeMcu module (a static access point that provides the WIFI network, a server, a client and a mobile access point attached to the remote surveillance object) programmed under Arduino IDE and communicating between them via the HTTP protocol.


INTRODUCTION
The development of the medical field largely resulted from the rapid development of technology. This has led to an increase in the average age of human beings and low mortality rates, especially in industrialized and developed countries [1]. The lack of modern medical equipment that helps diagnose and treat patients has led to poor medical services in developing countries and weak technology such as Third World countries .
Here in this project, we will create an IoT based health monitoring system that records body temperature and also send an email alert. Readings are recorded in the ThingSpeak and Google Sheets so that the patient's health can be monitored from anywhere in the world via the Internet.
Note that the communication between the different nodes is done by the HTTP protocol of the library ESP8266.h and the integrated development environment Arduino_IDE.
The rest of the paper is organized as follows. In section 2 related works were defined. In section 3 proposed system were explained.. In section 4 Hardware realizations were shown. In section 5 System implementation and the conclusion and future work was discussed in section 6.

NODEMCU (ESP8266)
The NodeMcu ESP8266 includes a WiFi module, memory, a serial link and manages GPIO ports. This microcontroller has the ability to perform activities related to WIFI.
In this article, we will discuss the use of the NodeMcu ESP8266 unit in the Internet of Things, (IoT) using AT or Arduino IDE commands for data exchange.

LM35 temperature sensor
This component makes it possible to measure the temperature around the sensor. It is precise, inexpensive, very easy to use and extremely reliable. The temperature measured by the sensor is proportional to the voltage on the analog output of the sensor. To reduce the difference between the actual temperature and the measured temperature, especially at extremes (around -55 ° and around 150 °).

Description
The LM35 series are precision integrated-circuit temperature devices with an output voltage linearly proportional to the Centigrade temperature. The LM35 device has an advantage over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from the output to obtain convenient Centigrade scaling. The LM35 device does not require any external calibration or trimming to provide typical accuracies of ±¼°C at room temperature and ±¾°C over a full −55°C to 150°C temperature range. Lower cost is assured by trimming and calibration at the wafer level. The lowoutput impedance, linear output, and precise inherent calibration of the LM35 device makes interfacing to readout or control circuitry especially easy. The device is used with single power supplies, or with plus and minus supplies. As the LM35 device draws only 60 μA from the supply, it has very low self-heating of less than 0.1°C in still air. The LM35 device is rated to operate over a −55°C to 150°C temperature range, while the LM35C device is rated for a −40°C to 110°C range (−10° with improved accuracy). The LM35series devices are available packaged in hermetic TO transistor packages, while the LM35C, LM35CA, and LM35D devices are available in the plastic TO-92 transistor package. The LM35D device is available in an 8-lead surface-mount small-outline package and a plastic TO-220 package.

ThingSpeak
ThingSpeak provides a great tool for IoT based projects. With ThingSpeak, we can monitor our data and control an online system, using the web pages provided by ThingSpeak, we can collect sensor data, analyze it, visualize it and finally trigger actions.
ThingSpeak will be used to monitor temperature online over the Internet. For this, it is necessary to set up the IFTTT platform to connect ThingSpeak to the messaging service so that the alert message can be sent whenever the patient is in a critical state. 1st step: Creation of a user account on ThingSpeak.com.  Step: Now you will see a template for channel creation, fill in the name and description as you want. Fill in "Temperature" and "Action" in the fields Field 1, Field 2, check the boxes of the fields. Finally, check Save channel. Now your new channel has been created Step: You will see three graphics as shown below. Note the write API key and we'll use that key in our code. Step: Now we will use the ThingHTTP app on the server to launch the IFTTT app to enter data into Google Sheets and send emails / SMS

ThingHTTP and IFTTT
ThingHTTP enables communication between devices, websites, and web services without having to implement the protocol at the device level. You can specify actions in ThingHTTP, which you want to perform with other ThingSpeak apps such as React. To make ThingHTTP new, we'll need a URL to run which we'll get from IFTTT

IFTTT:
IFTTT is a separate business from Google. Its name means "If This Then That".Your custom command and action form a whole called an "applet".

PROPOSED SYSTEM
The LM35DZ temperature sensor is powered by 3.3v generated by the NodeMcu board, the analog value Vin image of the temperature is sent to the Node board for processing.
The transfer of data between the NodeMcu card and the computer must go through the ThingSpeak site which is a website for the IoT. It is an interface that is used to connect software to services, to collect, store and analyze data.

HARWARD REALIZATION
In The Figure 10 shows the components of an "object detection and monitoring" system that includes: The LM35DZ temperature sensor, an NodeMcu.

System Implementation
The operation of the measuring system is based on the developed program which is executed by the NodeMcu card, which will then deliver all the measurements obtained each determined time interval.
The next is to send the measurements taken via wifi to the ThingSpeak site to be saved and displayed as graphs. The flowchart for the transmission of data from the NodeMcu card to the computer is shown in the figure.

Temperature Measurement
When turn on the energy, the system consists in sending the measurements carried out via wifi to the ThingSpeak site to be saved and displayed as graphs.

Discussions
The first series of tests with the NodeMCU assembled with Thingspeak server allowed us to obtain the following curve: the delay for taking measurements is carried out regularly by setting the "Delay" loop from the Arduino code one second for our example.

CONCLUSION
In this work we sought to design a system for measuring the temperature of a patient. It is composed of a temperature sensor, a NodeMcu microcontroller card whose the role is data processing and sending measurements to the ThingSpeak site for be recorded and displayed as graphs on a computer. As perspectives of this work, extensions of the measurement system can be considered taking into account other health variables such as blood pressure measurement and other measurements.