HX711 Load Cell

Using Arduino Project Guidance
1

Hello everyone. I am currently working on a project and I need to measure some weights. Something is going wrong when trying to calibrate the scale. IS this installation going to work if a hang up something with a rope from the load cell to measure or not?

link for image: 8e101c5b-7cd5-45e4-bc53-d756ba696d7b hosted at ImgBB — ImgBB

I am using this simple code to calibrate with a known weight but i get a positive number. Most tutorials I have seen the numbers are negative. Is that a problem?

#include "HX711.h"

const int LOADCELL_DOUT_PIN = A0;
const int LOADCELL_SCK_PIN = A1;

HX711 scale;

void setup() {
Serial.begin(9600);
scale.set_scale();
scale.tare();
}

void loop() {
float current_weight=scale.get_units(20);
float scale_factor= (current_weight/0.211); //the known weight is 211 grams
Serial.println(scale_factor);

}

2

ignore positivity/negativity of a number but the best calibration trick is done as follows:

put a 0 mass, read the number, call it, Xo ( whether it's + or - , just note it down)

now put a known mass(m), and read the number again, call this, Xm

so your calibration factor = (Xm - Xo) / m

so next time , your mass for a given reading - Xy , should be ( (Xy - Xo) / calibration factor)

3

I will give it a try..Is the installation ok to work properly?thank you

4

I have just tried it. The problem is that the measurements are not stable. Even though without mass on the load cell it start for example with -0.1 g and goes -0.7 without any change.

5

pahitas:
Is the installation ok to work properly?

i suggest you post your hand drawn circuit here,

odds of tracing wiring/set up in your image is about zero to none

visit this link that will walk you through steps to posting images inline on the forum

6

The wiring is fine. I am talking about the installation of the load cell on the piece of wood