Arduino HX711 load cell lots of drift

Question

I am trying to make this 50kg load cell work with this HX711 chip. I currently have the following connections :

• Load cell red -> E+
• Load cell black -> E-
• Load cell white -> A-
• Load cell green -> A+

I am using this library and this code :

#include "HX711.h"
#define calibration_factor -7050
HX711 scale;
void setup() 
{
 Serial.begin(9600);
 scale.begin(2, 3);
 scale.set_scale(calibration_factor);
 scale.tare();
}
void loop() 
{
 Serial.println(scale.get_units(1));
 delay(100);
}

The load cell appears to register load changes but the value is constantly going up (or down if the calibration_factor is positive). The value change rate is very high (from 0 to 300 in a couple of seconds).

Edit : I have 2 load cells and both of them do the same thing (with different HX711 chips).

Edit 2 : My question is : has anyone experienced this ? Or does anyone have an idea as to why this is happening ?

• jsotola: what is your specific question?
• Antoine Gagnon: Oups ! I edited the question @jsotola

Answer 1

The solution was to solder all the wires, now the drift seems to be very minimal or non existant.

• Motine: Hey Antoine, can you elaborate a little on your solution? What did you use before soldering? Did you just solder all wires and it just worked?
• Antoine Gagnon: Hey @Motine, This was a while ago, but IIRC I simply soldered the wires from the load cell to the HX711. Previously I was using a breadboard I think.