Comments on: ESP32 Web Server: Display Sensor Readings in Gauges

By: Sara Santos

Sara Santos — Thu, 02 Apr 2026 17:12:16 +0000

In reply to EnDy500. Hi. You'll need to save the Javascript library file to the ESP32 filesystem. Then, it will automatically be served by this line: server.serveStatic("/", LittleFS, "/"); You also have to modify the import in the HTML file from this: To this (if you name the file gauge.min.js): I hope this helps. Regards, Sara

By: EnDy500

EnDy500 — Mon, 30 Mar 2026 12:33:13 +0000

Thank you for this, it’s been very helpful for my project. Can you provide an example code of how to run this as an AP that can be view with no internet connection? Is there a way to add an icon to the gauges?

By: Sara Santos

Sara Santos — Thu, 15 Jan 2026 16:05:46 +0000

In reply to Roger Ashley.

Hi.

But did you upload those files to the board according to the instructions?

When you open the IP address on your browser, open the JavaScript console on the browser and check which error you get.

Regards,
Sara

By: Roger Ashley

Roger Ashley — Thu, 15 Jan 2026 15:57:43 +0000

Hi Sara, Below are my findings:
From “File Explorer”
Group File “Arduino_ESP32 Single File ESP32_gauge.
Under this heading::
data
ESP32_gauge.

Opening Data:::
Favicon
index
Script
Style

Opening index brings up picture of gauges
opening Script bring up
Script C:\Arduino_ESP32\ ESP32_gauges\data\script.js
Line 52
Char 1
Error Expected identifier, string or number
Code 800A0404
Source JavaScript compitation error

opening Style.css
brings up file sript.

Hope this all makes sense and may help my dead stop.

By: Sara Santos

Sara Santos — Thu, 15 Jan 2026 15:27:20 +0000

In reply to Roger Ashley.

Hi.
Did you upload the files to the Filesystem?
Check the section “Uploading Code and Files”.
Regards,
Sara

By: Roger Ashley

Roger Ashley — Thu, 15 Jan 2026 06:54:06 +0000

Hi Sara,
Just come across this tutorial, tried and all went well until I viewed the web page 192.168.0.83 this just gave me “Handler did not hanle the request”… Tried all I know, any ideas please.

By: Sara Santos

Sara Santos — Wed, 03 Dec 2025 15:06:59 +0000

In reply to Peter van der Lee.

Hi.

I’m sorry, but I don’t think I can help you with your issue as I’m not familiar with that particular ESP8266.

Regards,
Sara

By: Peter van der Lee

Peter van der Lee — Sun, 30 Nov 2025 18:48:42 +0000

Hi Rui and Sara,
Based on your example of the webserver for the GPIO Output and the webserver for Gauges I made a project for a camper van. Information from water tanks and temperature meters is read. The actuators I control via my Mega 2560 are solenoid valves and water pumps (via Relays). I also used example “2.5 – WebSocket Web Server: Control Multiple Outputs” from the e-book.
The project I made run very well on a NodeMCU with the original binary software.
For the second step I wanted to transfer this project to a Mega-WiFi_R3_ATmega2560_ESP8266 board, because I have 5 analog tank level sensors in my project.
The Test version I made was running fine on my NodeMCU ESP8266., working with 1 analog input. I used the NodeMCU because during development I didn’t want to have to change the switches on the Mega-WiFi_R3_ATmega2560_ESP8266 board every time. When I was ready to transfer my project from the NodeMCU to the Mega-WiFi_R3_ATmega2560_ESP8266 I first flashed the firmware on the ESP8266 (on the Mega-WiFi_R3_ATmega2560_ESP8266) with AT firmware, because I saw that in many other examples people were using the AT commands for communication between the Mega and the ESP8266.
Then I found out that many of the libraries (ESP8266WiFi.h, ESPAsyncTCP.h, ESPAsyncWebServer.h ) were made specific for the ESP8266 and did not run on the Mega part. So my conclusion was I had to run the webserver part on the ESP8266 chip of the Mega-WiFi_R3_ATmega2560_ESP8266 board.
But I found out that the webserver is not running ok on the ESP8266 of the Mega-WiFi_R3_ATmega2560_ESP8266 board. Can this be because of the AT firmware?
But now my question: how can I change back to the original firmware on the ESP8266 in the Mega-WiFi_R3_ATmega2560_ESP8266 board? I hope you can help me with that, or send me in the right direction.
Or will an original binary file for the NodeMCU work on the Mega-WiFi_R3_ATmega2560_ESP8266 board?

Kind regards, Peter

By: Sara Santos

Sara Santos — Sat, 08 Mar 2025 06:20:03 +0000

In reply to Klaus.

Hi.
It may also help taking a look at this: https://rntlab.com/question/solvedassert-failed-tcp_alloc-idf-components-lwip-lwip-src-core-tcp-c1851-required-to-lock-tcpip-core-functionality/
Regards,
Sara

By: Klaus

Klaus — Fri, 07 Mar 2025 11:48:02 +0000

Oh, sorry. Mein Fehler. Habe gerade noch einmal geschaut und festgestellt, dass dass es noch eine AsyncTCP neben der AsyncTCP-Master gab. Diese wurde vermutlich beim compilieren gezogen. Habe die AsyncTCP gelöscht, neu compiliert und? Es funktioniert!!
Vielen Dank für die tolle Arbeit!!!

Gruß Klaus