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

By: Jeff

Jeff — Wed, 23 Jul 2025 21:09:38 +0000

Hello, my readings are spot on…except they are in the negative ( -100g). My bridge is orientated correctly. I tried removing the negative from the calibration code, but that makes the readings way off from actual. How can I correct this? Thanks for your help and time.

By: Sara Santos

Sara Santos — Sat, 25 Jan 2025 11:39:19 +0000

In reply to Peter Jonasson.

Hi.
Thanks for the suggestion.
I added a blank column between each side of the HX711.

Regards,
Sara

By: Peter Jonasson

Peter Jonasson — Fri, 24 Jan 2025 14:11:53 +0000

This is a fantastic article and a well-written guide! My students are finding it incredibly helpful.

If I could offer just a small suggestion—under the section ‘Wiring Load Cell and HX711 Amplifier to the Arduino,’ there’s a hookup table that might be a bit tricky for first-time circuit builders. Some of my students initially misunderstood the horizontal boxes as common connections, rather than each side of the HX711. As a result, they accidentally wired +5 to A+ and GND to E+, which led to some unexpected outcomes.

That said, this is still an excellent NERD TUTORIAL, and I appreciate the work you’ve put into it!

By: Ehren W

Ehren W — Thu, 12 Dec 2024 16:02:53 +0000

In reply to Ehren W.

I think I figured it out. Changing “int” to “double” in a few lines, and modifying the reading gets it to display to the hundredths place. I’d like it to only display to the tenths place. I’ll update if I find out how.

Specifically:
“int reading” and “int lastReading” (~line 30) get changed to “double reading” and “double lastReading”

“void displayWeight(int weight){” (~line 50) gets changed to “void displayWeight(double weight){”

“reading = round(scale.get_units());” (~line 90) gets changed to “reading = round(scale.get_units()*10.0)/10.0;”

By: Ehren W

Ehren W — Mon, 02 Dec 2024 14:44:45 +0000

Hi Sara,
Thanks for the tutorial, this is just what I was looking for. I got my scale up and running. I’m using a 50kg load cell and would like to display the weight to the nearest 0.1kg. Changing the label was easy, displaying a decimal is beyond my ability (I’m a biologist by training). Is there an easy way to make that change in the code?

Thanks

By: oluka samuel

oluka samuel — Sun, 05 May 2024 10:15:41 +0000

After placing a known weight am getting different values on the serial monitor with value should i consider to use for calculating my calibration factor

By: Ruan

Ruan — Mon, 29 Apr 2024 09:42:10 +0000

Hi Sara, firstly we all thank you for your speedy replies, everytime!

(This is a repost from another thread)
My question is, does this library auto scale your loadcell values, so that you dont exceed the mV per Volt range? ( I dont know how to phrase it properly, I want to span my measured values. Meaning I want to have it only read 0 – 5kg or 0 – 3000kg depending on what I set the span value to)
To clarify, everything is working perfectly, and I have had it running for awhile for different application, my common problem I run into is that my values tends to drift after a few hours although the temp and load-cell stays the same with or without weight applied on the load cell.
My load-cells are configured through Wheatstone bridge configuration.
I am pretty sure that if I span it better that this problem could go away.
Thank you in advance!

By: Sara Santos

Sara Santos — Thu, 15 Feb 2024 10:41:12 +0000

In reply to Don.

Hi.
Don’t worry about that.
You can follow this tutorial: https://randomnerdtutorials.com/esp32-load-cell-hx711/
Regards,
Sara

By: Don

Don — Sun, 11 Feb 2024 02:23:02 +0000

I want to use a load cell + amplifier for an ESP32-based project but I am concerned about the voltage level needed for VCC on most breakout boards.

AFAICT a 5V supply is needed for the HX711 breakout board but the means that the signal lines will also be at 5V when for an ESP32 they need to be 3.3V.

By: Sarah

Sarah — Mon, 15 Jan 2024 12:42:07 +0000

also the above code sometimes run good but after few minutes it goes into setup body and consider the weight as tare