Load cell is not working

Using Arduino Sensors
1

Hello guys, I'm having some problems with my load cell.

At first, it looks like is working fine but then I noticed that when my hand gets close to the cell, it changes the values of serial monitor. Another thing that I noticed, is that when I use some metal as wheight the cell doesn't change de value, it's like there is nothing on it. Does anybody ever heard about something like this? What is the problem? How can I fix this?

2

One option is praying. Another is to provide all necessary information about your setup to get help here.

3

Does that mean that you could put a weight on it and get the expected value on the serial monitor? If it doesn't mean that, then can you explain what it means?

That sounds like a noise pick up problem. Show us your wiring.

Does that only happen with metal weights? The way you wrote that sounds like it works with non-metallic weights.

4

A good start would be to post a schematic including all parts and your code using code tags. We have no way of seeing exactly what you have? My crystal ball is out of service at the moment. :slight_smile:
Ron

5

That is a sure sign of "floating input", due to poor connection or incorrect wiring.

Please provide the necessary information, after reading and following the instructions in the "How to get the best out of this forum" post, linked at the head of every forum category.

6

Hello! i'm sorry I did not gave you all the necessary information, thank you for answering me in a kind way. Yes, it is only happening with metal weights.
Here is the circuit and the code:

#include "HX711.h"
#include "LiquidCrystal_I2C.h";
 
#define DT A1
#define SCK A0
 
HX711 escala;
 
LiquidCrystal_I2C lcd(0x27, 16, 2);
 
void setup() {
  escala.begin (DT, SCK);
 
  lcd.init();
  lcd.backlight();
 
  Serial.begin(9600);
  Serial.print("Leitura do Valor ADC:  ");
  Serial.println(escala.read());   // Aguada até o dispositivo estar pronto
  Serial.println("Nao coloque nada na balanca!");
  Serial.println("Iniciando...");
  escala.set_scale(397930.55);     // Substituir o valor encontrado para escala
  escala.tare(20);                // O peso é chamado de Tare.
  Serial.println("Insira o item para Pesar");
}
 
void loop() {
  lcd.setCursor(4, 0);
  lcd.print("USINAINFO");
  lcd.setCursor(0, 1);
  lcd.print("Peso: ");
  lcd.print(escala.get_units(20), 3);
  lcd.println(" kg  ");
  delay(1000);
}

image

7

Please post a close-up focused photo showing the soldered header pin connections or soldered wire joints to the load cell amplifier. A bad solder joint can easily lead to the problem you describe.

8

Hello, i'm so sory for not giving you all the informations. I just put the code and de wiring herer. Thank you for trying to help!

9

lol