Comments on: ESP8266 NodeMCU Relay Module – Control AC Appliances (Web Server)

By: Sara Santos

Sara Santos — Tue, 07 Oct 2025 14:17:28 +0000

Great.
Thanks.
Regards,
Sara

By: Christoph Krzikalla

Christoph Krzikalla — Tue, 07 Oct 2025 12:40:04 +0000

Hello Sara,
yes! this did the trick. Not being very knowledgeable in the Arduino C## world, simple things like breaking changes in libraries can easily thow one of the track.
I’ve seen that you’ve already updated the code on randomnerdturorials.com. Absolutely perfect and professional.
Muito obrigado!
Chris

By: Chris

Chris — Fri, 03 Oct 2025 07:48:53 +0000

Thank you very much. I’ll try this out as soon as I’m back home in a couple of days.
Kind regards
Chris

By: Sara Santos

Sara Santos — Wed, 01 Oct 2025 20:24:19 +0000

In reply to Chris Krzikalla.

Hi.

A new update on the core probably broke what was previously working.

To fix the issue:

replace
request->send(200, “text/html”, index_html, processor);
with
request->send_P(200, “text/html”, index_html, processor);

Let me know if this fixes the issue.

Regards,
Sara

By: Sara Santos

Sara Santos — Sun, 28 Sep 2025 15:26:19 +0000

In reply to Chris Krzikalla.

Hi.
I’ll try it out, but I’m currently out of the office.
I can only do that in a few days.

Regards,
Sara

By: Chris Krzikalla

Chris Krzikalla — Thu, 25 Sep 2025 09:57:25 +0000

In reply to Sara Santos.

Hello,
same problem here. My ESP8266 (D1 Mini) connects to the WiFi but as soon as I call its IP Address with a browser, I get a Memory Pointer Error or something similar.
The IDE error message is:Exception (3):
epc1=0x4000bf64 epc2=0x00000000 epc3=0x00000000 excvaddr=0x4023fb7d depc=0x00000000
and then a lot of hex numbers from the stack.
I assume it’s a library problem. I use AsyncTCP Version 3.4.8 from ESP32Async and ESPAsyncWebServer version 3.8.1. from ESP32Async. I tried several older versions but to no avail.
I tried several browsers (firefox, Safari, Edge) … doesn’t help.
Can you try this out and see for yourself?
Kind regards
Chris

By: Sara Santos

Sara Santos — Tue, 29 Apr 2025 15:23:28 +0000

In reply to Jose Hodak.

Hi.
Unfortunately, no.
I haven no idea what might be causing the issue.
Do you have any antivirus or other extensions on the browser?
What ESP8266 board model are you using?
Regards,

Sara

By: Jose Hodak

Jose Hodak — Tue, 29 Apr 2025 03:55:05 +0000

Hello, Sara
Unfortunately, I do not know much about the Java debugging console. I have tried what you suggested the best way I could:
1-compile and flush the cude into the nodemcu and use the serial monitor to see the connection status and IP adress. This gave me 192.168.0.14.
2-After pasting the ip address of the nodemcu esp8266 on google chrome on my laptop I do not see the webpage, and an error:
This site can’t be reached
The connection was reset.
Try:

Checking the connection
Checking the proxy and the firewall
Running Windows Network Diagnostics
ERR_CONNECTION_RESET
Is shown.

At this stage the serial monitor shows text as i described two posts ago.

3-On google chrome i press Ctrl+Shift+J to open the java console
Under the “Network” tab i see the following:

192.168.0.14 (failed)net::ERR_CONNECTION_RESET document 0.0 kB 9.61 s
192.168.0.14 (canceled) document Other 0.0 kB 9.66 s
192.168.0.14 (canceled) document Other 0.0 kB 9.59 s
192.168.0.14 (failed)net::ERR_CONNECTION_RESET document 0.0 kB 11.74 s
Imagedata:image/png;base… 200 png chrome-error://chromewebdata/:1505 (memory cache) 0 ms
Imagedata:image/png;base… 200 png chrome-error://chromewebdata/:1505 (memory cache) 0 ms
Imagedata:image/png;base… 200 png chrome-error://chromewebdata/:1505 (memory cache) 0 ms
Imagedata:image/png;base… 200 png chrome-error://chromewebdata/:1505 (memory cache) 0 ms
Imagedata:image/png;base… 200 png chrome-error://chromewebdata/:1505 (memory cache) 0 ms
Imagedata:image/png;base… 200 png chrome-error://chromewebdata/:1505 (memory cache) 0 ms
If I reload the page (192.168.0.14) I get additional lines on this table under “network”, that look like the last ones pasted here.
Is this information helpful to figure out what is happening?

By: Sara Santos

Sara Santos — Mon, 28 Apr 2025 09:57:43 +0000

In reply to Jose Hodak.

Hi.
Is your computer on the same network of the ESP8266?
Can you open the web browser javascript console when you try to access the web page and see which error you get.
Regards
Sara

By: Jose Hodak

Jose Hodak — Sun, 27 Apr 2025 23:31:23 +0000

Hello Sara,
I tried 3 different boards. Two of them were the NOD-MCU ESP8266, but they are sligthly different judging by the laser marking on the metal shielding. Then I went on and tried an ESP-07 board. In all 3 cases the results are exactly the same. The connection to the WIFI router is succesful, I get the IP address from the serial monitor and paste it on the web browser (Chrome and Edge do the same). Thn tere is text being posted in the serial monitor but the browser says that the page can not be reached. I do not get to see the webpage with the buttons as you show. It seems unrelated to the boards, and to the browser. But what could it be?
Thanks again for looking into this issue.