Comments on: ESP8266 NodeMCU with Load Cell and HX711 Amplifier (Digital Scale)

By: Ramon

Ramon — Sat, 22 Feb 2025 15:43:08 +0000

Good afternoon;
Thank you very much for your tutorials, they are very helpful for any of my personal projects.
I am trying to measure small weights, less than a gram.
I have changed the variables
int reading;
int lastReading;
for
float reading;
float lastReading;

both on the screen and on the serial monitor it appears 0.00 but when I put in some weight it always rounds up.
Could you help me?
Thank you for all your work.

By: Sara Santos

Sara Santos — Thu, 27 Jun 2024 09:54:29 +0000

In reply to Jayme.

That’s great.
I’m glad you like our tutorials and thank you so much for supporting our work.

Regards,
Sara

By: Jayme

Jayme — Thu, 27 Jun 2024 05:46:03 +0000

Dear Rui and Sara, I would like to thank you and congratulate for the outstanding job!
I have been following you for many years now, and thanks to you I developed a fairly good understanding of the Arduino environment. I was looking for a retirement hobby and your books – I bought almost all of them, including the latest on LVGL – helped me immensely!
Nowhere else I could find such good material, guiding step by step in every detail.
Your books and tutorials are the very best!

By: Sara Santos

Sara Santos — Tue, 01 Aug 2023 09:18:26 +0000

In reply to Murphy.

Hi.
Make sure you installed the required libraries.
Regards,
Sara

By: Murphy

Murphy — Sun, 30 Jul 2023 16:58:40 +0000

I am a keen follower of your blog, you are doing a fantastic job. I followed the instructions and i was getting this error in my arduino sketch
(Arduino: 1.8.19 (Windows 10), Board: “NodeMCU 1.0 (ESP-12E Module), 80 MHz, Flash, Disabled (new aborts on oom), Disabled, All SSL ciphers (most compatible), 32KB cache + 32KB IRAM (balanced), Use pgm_read macros for IRAM/PROGMEM, 4MB (FS:2MB OTA:~1019KB), 2, v2 Lower Memory, Disabled, None, Only Sketch, 115200”

prototyping:20:7: error: no matching function for call to ‘HX711::HX711()’

20 | HX711 scale;

| ^~~~~

In file included from C:\Users\USER\Documents\Arduino\prototyping\prototyping.ino:14:

C:\Users\USER\Documents\Arduino\libraries\HX711/HX711.h:23:3: note: candidate: ‘HX711::HX711(byte, byte, byte)’

23 | HX711(byte dout, byte pd_sck, byte gain = 128);

| ^~~~~

C:\Users\USER\Documents\Arduino\libraries\HX711/HX711.h:23:3: note: candidate expects 3 arguments, 0 provided

C:\Users\USER\Documents\Arduino\libraries\HX711/HX711.h:10:7: note: candidate: ‘constexpr HX711::HX711(const HX711&)’

10 | class HX711

| ^~~~~

C:\Users\USER\Documents\Arduino\libraries\HX711/HX711.h:10:7: note: candidate expects 1 argument, 0 provided

C:\Users\USER\Documents\Arduino\prototyping\prototyping.ino: In function ‘void setup()’:

prototyping:24:9: error: ‘class HX711’ has no member named ‘begin’

24 | scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);

| ^~~~~

Multiple libraries were found for “HX711.h”

Used: C:\Users\USER\Documents\Arduino\libraries\HX711

Not used: C:\Users\USER\Documents\Arduino\libraries\HX711-master

Not used: C:\Users\USER\Documents\Arduino\libraries\HX711_Arduino_Library

exit status 1

no matching function for call to ‘HX711::HX711()’

This report would have more information with
“Show verbose output during compilation”
option enabled in File -> Preferences.
)

By: kk

kk — Wed, 15 Mar 2023 05:26:45 +0000

Hi,
I am trying to connect load cell on bottle with esp8266 and that data in want to send it to nodemcu and then it will print the value of load cell and also predict that when it will going to empty. There will be continuous monitoring of data. Problem we re facing is that we don’t have idea about hoe to do calibrate loadcell data into Nodemcu, also calculation prlm in loadcell,

By: Chris

Chris — Tue, 02 Aug 2022 22:10:15 +0000

In reply to Sara Santos. Great, thanks

By: Sara Santos

Sara Santos — Tue, 02 Aug 2022 17:46:34 +0000

In reply to Chris.

Hi.
As long as you have two different GPIOs for each HX711 and load cell, it will be fine with one MCU.
Regards,
Sara

By: Chris

Chris — Tue, 02 Aug 2022 08:22:55 +0000

I want to make 4 scales
Is it possible to connect more than 1 load cell, with its HX711, to a single Node MCU, or would I need four Node MCUs?
Many thanks
Chris

By: Sara Santos

Sara Santos — Sun, 05 Jun 2022 16:09:46 +0000

In reply to Suriya Prakash J J.

Hi.
When you get a lot of dots on the Serial Monitor in a code like yours, it probably means that the ESP is not able to connect to your local network.
Please check the network credentials and that the ESP8266 is relatively close to your router to catch the Wi-Fi signal.
Regards,
Sara