No changing in output value from HX711 module

[fra_geek]

Hi everyone,
I'm new to using Arduino, I'm working to get the deformation of an object by two strain gauges, so with an half-bridge.
The problem is that I don't have any variation in the output from the HX711 module.
Would be great if I could get some advice as to why I'm not getting any results and do let me know if I can provide more information to get assistance.

#include "HX711.h"

// HX711 circuit wiring
const int LOADCELL_DOUT_PIN = 2;
const int LOADCELL_SCK_PIN = 3;

HX711 scale;

void setup() {
  Serial.begin(57600);
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
}

void loop() {

  if (scale.is_ready()) {
    long reading = scale.read();
    Serial.print("HX711 reading: ");
    Serial.println(reading);
  } else {
    Serial.println("HX711 not found.");
  }

  delay(1000);
  
}

[gilshultz]

Are you sure it is connected correctly? From your Frizzy picture I can understand why, you have no power connected to the Arduino? Posting a schematic would help a lot. You state a HX711 module, which one? There are several with different pinouts.

[Boffin]

You have another thread on this topic Strain gages wheat-stone bridge
I showed you that your scheme is wrong.
You dropped that stream and opened a new one.
I know that cross-posting is not welcomed on the forum.
Why are you doing this?

[fra_geek]

Thanks for the answer, what you mean with no power connection to Arduino?
Hope this schematic could be helpful.

[fra_geek]

I'm using your scheme but still not working so I thought that the problem should be on a different component like the HX711 Module or the code.

[MarkT]

The fritzing shows you are combining strain elements and fixed resistors in an asymmetrical manner - this will account for the HX711 output being jammed to the rail.

You have to have accurate resistance match in a bridge like this, using 0.1% resistors or better, so the voltage difference going into the HX711 is a few millivolts only.

Unless the resistors are high precision and low tempco, the output will drift all over the place as the temperature fluctuates.

[TomGeorge]

Hi,
Can you please draw your circuit with pen(cil) and paper?
It will be clearer than the mass of crossed line Fritzy has provided.

Do you have a DMM?

Have you tried the HX711 example in the IDE?

Thanks.. Tom..