I’m trying to understand how the HX711 works and I’m facing some challenges. I recently conducted tests using a 5 kg load cell and applied standard weights while measuring the voltage across the strain gauge for each weight.
Here’s a summary of my procedure:
Connection of the Load Cell: I connected the wires of the load cell as follows:
Excitation terminals to E+ and E-
Output terminals to A+ and A- of the HX711.
Voltage Measurement: I measured the voltage across the gauge for each applied weight.
Retrieval of Raw Values: I then connected the load cell to the HX711 circuit and retrieved the raw values corresponding to the same weights used previously.
However, when I calculated the raw values using the following formulas, I found values that were very different from those measured:
Amplification Formula:
Vout=Gain×Vin(with Gain = 128)
Analog-to-Digital Conversion Formula:
Raw Value=(VrefVout)×(2n−1)
Could anyone clarify this discrepancy in results? Does the HX711 use a different method for amplification or signal conversion?
Thank you for your help!