Load Cell Amplifier HX711 doesn't work

I have this Load Cell Amplifier and load cell 0,01 - 300g, but I couldn't figure out how to mesure small things. I measure coins, I have to know the coin weight to determine how many of them on the load cell. Actually I don't need to know how many gramms or whatever they are, I need to be able to distinguish between the two denominations of coins in their weight. When I start calibtation sketch and put my coin I see this and nothing more What should I do? Thanks

How can we guess without seeing your code?

Oh, sorry. It's just standard Sparkfun's sketch, which I had not changed.

#include "HX711.h"

#define DOUT  3
#define CLK  2

HX711 scale(DOUT, CLK);

float calibration_factor = -7050; //-7050 worked for my 440lb max scale setup

void setup() {
  Serial.begin(9600);
  Serial.println("HX711 calibration sketch");
  Serial.println("Remove all weight from scale");
  Serial.println("After readings begin, place known weight on scale");
  Serial.println("Press + or a to increase calibration factor");
  Serial.println("Press - or z to decrease calibration factor");

  scale.set_scale();
  scale.tare();    //Reset the scale to 0

  long zero_factor = scale.read_average(); //Get a baseline reading
  Serial.print("Zero factor: "); //This can be used to remove the need to tare the scale. Useful in permanent scale projects.
  Serial.println(zero_factor);
}

void loop() {

  scale.set_scale(calibration_factor); //Adjust to this calibration factor

  Serial.print("Reading: ");
  Serial.print(scale.get_units(), 1);
  Serial.print(" lbs"); //Change this to kg and re-adjust the calibration factor if you follow SI units like a sane person
  Serial.print(" calibration_factor: ");
  Serial.print(calibration_factor);
  Serial.println();

  if(Serial.available())
  {
    char temp = Serial.read();
    if(temp == '+' || temp == 'a')
      calibration_factor += 10;
    else if(temp == '-' || temp == 'z')
      calibration_factor -= 10;
  }
}

Any change when you apply a much stronger force to the guage?

Not really,

it's give strange not really usefull feedback.

But when I try another Sparkfun's example here is more valuable feedback with whom I can do something, but still very unstable pic

#include "HX711.h"

#define calibration_factor 100.0 //This value is obtained using the SparkFun_HX711_Calibration sketch

#define DOUT  8
#define CLK  9

HX711 scale(DOUT, CLK);

void setup() {
  Serial.begin(9600);
  Serial.println("HX711 scale demo");

  scale.set_scale(calibration_factor); //This value is obtained by using the SparkFun_HX711_Calibration sketch
  scale.tare();    //Assuming there is no weight on the scale at start up, reset the scale to 0

  Serial.println("Readings:");
}

void loop() {
  Serial.print("Reading: ");
  Serial.print(scale.get_units(), 1); //scale.get_units() returns a float
  Serial.print(" lbs"); //You can change this to kg but you'll need to refactor the calibration_factor
  Serial.println();
  delay(1500);
}

Then your load cell is not suited for such small weights.

I took these load cell of scales and with native chip all worked normal

t_serkov: I took these load cell of scales and with native chip all worked normal

Then, either that load cell is not compatible with the HX711, or your wiring is incorrect. The data in your second image is extremely noisy. That is suspicious.

I am facing similar problem. I’m trying to use a single load sensor SEN-10245 with HX711 and an Arduino, using the code and hookup shown on pictures below.

Serial monitor shows “0.0 g”.

hookup

Sen 10245 HX711
Black wire ==> E- (vss)
Red wire ==> A- (signal)
White wire ==> E+ (vcc)

HX711 arduino
gnd ==> gnd
vcc ==> vcc
dt ==> A2
sck ==> A3

Somebody could help me?

Thanks.

teste_sensor_de_carga_1.ino.ino (419 Bytes)

Hi everone,
I have loadcell Amplifier HX711. I made the circuits and I wanted to try this code.

#include <Hx711.h>
Hx711 scale(A2, A3);

void setup() {
Serial.begin(9600);
}

void loop() {
Serial.print(scale.getGram(), 1);
Serial.println(" g");
delay(200);
}

But, Arduino gives a message in the picture. I dont know, What did I forget? I downloaded and added the HX711 librarry. Could you help me if there is an idea about ths?
thanks. :slight_smile:

The HX711 (and hence the Sparkfun board that uses it) is designed to work with multiple load cells configured as a Wheatstone Bridge. Is that your configuration, or do you just have a single load cell? Post a picture of your schematic.

Also, consider buying the Sparkfun OpenScale board:

https://www.sparkfun.com/products/13261

It comes with HX711, a microcontroller, and working firmware. You can also reprogram it using the Arduino Uno setting in the IDE. Even if you don’t end up using it in your project, it’s a great way to get started and learn about using load cells. That’s what I did when I started working on my Kegerator Monitor project.

Greg

Why did you waste bandwidth posting a picture of text? Do NOT do that again. Post your code AS TEXT. Post the errors AS TEXT.

It is obvious that you have not download and properly installed the appropriate library.

Samixx: What is the difference between Sparkfun OpenScale and AnyLoad A1A-22 Load Cell Amplifier ?

$140.00

hi, i’m new and i’m trying to use 20kg load cell with hx711. i’m using this code :

#include “HX711.h”
#define DOUT 3
#define CLK 2
HX711 scale;

float weight;
float calibration_factor = 419640; // for me this value works just perfect 419640
void setup() {
Serial.begin(9600);
Serial.println(“HX711 calibration sketch”);
Serial.println(“Remove all weight from scale”);
Serial.println(“After readings begin, place known weight on scale”);
Serial.println(“Press + or a to increase calibration factor”);
Serial.println(“Press - or z to decrease calibration factor”);
scale.set_scale();
scale.tare(); //Reset the scale to 0
long zero_factor = scale.read_average(); //Get a baseline reading
Serial.print(“Zero factor: “); //This can be used to remove the need to tare the scale. Useful in permanent scale projects.
Serial.println(zero_factor);
}
void loop() {
scale.set_scale(calibration_factor); //Adjust to this calibration factor
Serial.print(“Reading: “);
weight = scale.get_units(5);
//Serial.print(scale.get_units(), 2);
// Serial.print(” lbs”); //Change this to kg and re-adjust the calibration factor if you follow SI units like a sane person
Serial.print(“Kilogram:”);
Serial.print( weight);
Serial.print(” Kg”);
Serial.print(" calibration_factor: ");
Serial.print(calibration_factor);
Serial.println();
if(Serial.available())
{
char temp = Serial.read();
if(temp == ‘+’ || temp == ‘a’)
calibration_factor += 10;
else if(temp == ‘-’ || temp == ‘z’)
calibration_factor -= 10;
}

}

but the result is as shown in the picture attached. can somebody please help me? thank you.