IoT Analog Dial Gauge

Updated: Jul 2, 2021

In this tutorial to Learn and uses of JavaScripts, CSS and HTML. Here we are using LDR reading analog value of ADC and display it on HTML web page, which is served by ESP8266 Web server.


And also SPIFFS lets you access the flash chip memory like you would do in a normal filesystem in your computer, but simpler and more limited. You can read, write, close, and delete files. SPIFFS doesn’t support directories, so everything is saved on a flat structure.

Using SPIFFS with the ESP8266 board is specially useful to:

  • Create configuration files with settings;

  • Save data permanently;

  • Create files to save small amounts of data instead of using a microSD card;

  • Save HTML and CSS files,JavaScripts to build a web server;

  • Save images, figures and icons;

  • And much more.



In most of our web server projects, we’ve written the HTML code for the web server as a String directly on the Arduino sketch. With SPIFFS, you can write the HTML and CSS in separated files and save them on the ESP8266 filesystem.

refer previous tutorial about SPIFFS. https://www.dofbot.com/post/esp8266-spiffs-uploader


ESP8266 have only one adc channel. Lets begin to read analog and make something cool.


Circuit Diagram