Series) This project demonstrates how to construct a web server using the ESP8266 NodeMCU board so that sensor readings can be plotted in charts that contain more than one series. On the same chart, we will plot the readings from four different DS18B20 temperature sensors so that you can see how this works. You are free to modify the project in order to plot any other data you require. We will be utilizing the Highcharts JavaScript library in order to create the charts.

This project will build a web server with the ESP8266 NodeMCU board. The web server will display temperature readings from four DS18B20 temperature sensors on the same chart; the chart will have multiple series. The chart can show a maximum of forty data points for each series, and it refreshes itself with fresh data every thirty seconds. These values can be changed in your code as you see fit. DS18B20 Temperature Sensor The DS18B20 temperature sensor is a digital temperature sensor that only requires a single wire to operate. This indicates that only a single data line is necessary in order to successfully communicate with your microcontroller.

Because every sensor has its own one-of-a-kind 64-bit serial number, it is possible to connect multiple sensors to the same GPIO, which is exactly what we're going to do in this tutorial. Find out more information regarding

Server-Sent Events Server-Sent Events are used to ensure that the readings on the website are kept up to date automatically (SSE). Those files that have been saved on the filesystem (LittleFS)

The HTML, CSS, and JavaScript files that will be used to construct the web page will be saved on the filesystem of the board. This will ensure that our project is better organized and easier to comprehend (LittleFS).

ESP8266 (read Best ESP8266 development boards) 4x DS18B20 temperature sensor (one or multiple sensors), in a water-resistant version 4.7k Ohm resistor A set of jumper wires Breadboard Prerequisites Before moving on with the project, you must first ensure that all of the prerequisites outlined in this section have been met.

1. Open the Arduino Software and Install the ESP8266 Board Using Arduino IDE, we'll write some code for the ESP8266. Therefore, the ESP8266 add-on component needs to be installed on your system. 2. Filesystem Uploader Plugin We will be utilising a plugin for the Arduino IDE known as the LittleFS Filesystem uploader in order to upload the HTML, CSS, and JavaScript files to the flash memory (LittleFS) of the ESP8266. 3. Installing Libraries You will need to install the following libraries in order to construct this project: OneWire, which was developed by Paul Stoffregen and is managed by the Arduino Library Manager; DallasTemperature, which is also managed by the Arduino Library Manager; the Arduino JSON library, which was developed by Arduino and is currently at version 0.1.0 (Arduino Library Manager) ESPAsyncWebServer (.zip folder); ESPAsyncTCP (.zip folder). You will need to use the Arduino Library Manager in order to install the first two libraries. Find the library's name by going to Sketch > Include Library > Manage Libraries and searching for it there. Due to the fact that the ESPAsyncWebServer and AsynTCP libraries cannot be installed using the Arduino Library Manager, it is necessary for you to manually copy the library files into the folder designated for Arduino Installation Libraries. Alternately, you can select the libraries you just downloaded by going to the Sketch menu in your Arduino IDE, selecting the Include Library option, and then clicking the Add.zip Library button. Library Installation (VS Code + PlatformIO)

If you are using PlatformIO to write code for the ESP8266, you need to add the following lines to the platformio.ini file in order to include the libraries (you should also change the speed of the Serial Monitor to 115200): You can use three or two DS18B20 sensors if you don't have enough of them to use all four. Alternately, you can also use other sensors (though doing so will require you to modify the code), as well as data from any other source (for instance, sensor readings received via MQTT, ESP-NOW, or random values—to experiment with this project...)

Connect four DS18B20 sensors to your board using the wires provided.

Finding Out the Addresses of the DS18B20 Sensors A unique serial number is allotted to each individual DS18B20 temperature sensor. To begin, you will need to locate that number so that you can label each sensor appropriately. You need to do this so that you will later be able to identify the temperature sensor from which you are reading the value. Wire only one sensor at a time to determine its address (or add a new sensor one by one), and repeat this process until you are able to recognize each

device based on its address. After that, you will be able to attach a physical label to every sensor. After opening the Serial Monitor with a baud rate of 115200 and pressing the RST/EN button found on the circuit board, you should see something similar to the following (but with different addresses): To enable you to copy the addresses, uncheck the box labelled "Autoscroll" in the options menu. In our

Sensor 1: 28 FF A0 11 33 17 3 96 Sensor 2: 28 FF B4 6 33 17 3 4B Sensor 3: 28 FF 11 28 33 18 1 6B Sensor 4: 28 FF 43 F5 32 18 2 A8

Launch your web browser, then type the ESP8266's IP address into the address bar. It is recommended that you gain access to the web page that displays the sensor readings. Please be patient while it collects some data points and wait some time. You can select a point to view its value as well as the timestamp it was last updated.

Wrapping Up You have learned how to make charts with multiple series to display temperature from various DS18B20 sensors from this project. You have the ability to customize this project to generate any number of charts and series you desire, as well as plot data from any other sensors or sources.