HX711_ADC Arduino library for HX711 24-Bit Analog-to-Digital Converter for Weight Scales Olav Kallhovd sept2017

[Marce3838]

Dear Friends:

I salute you. I am trying to create a digital scale with the ADC HX-711. The load cell that I use is 20Kg. For this I use the library Olav Kallhovd sept2017. I have problems in the calibration process. This is because it first assumes strange calibration values using the same reference weight. these values oscillate between -218.45 and 40.95. The strangest thing is the output values. which range from: "VAL inf" to oscillatory and meaningless values. Is it possible that the load cell or the circuit is damaged?

Best regards

[Wawa]

If you have problems with a HX711, then you should check a few things first.

1. Measure resistance between E- and Gnd. It should be < 1ohm.
   If not, then you have a faulty board. It has no ground plane at the bottom.
   You can correct that by soldering a wire between those two points.

2. You can't use a common HX711 board with a 3.3volt-logic processor.
   So an Uno, Mega or classic Nano would be fine, a Due, ESPxx or newer Nano not.
   For 3.3volt-logic processors you need a Sparkfun HX711 board, with two power connections.
   Leo..

[xfpd]

"inf" indicates "divide by zero" error.

[Whandall]

@Wawa

You can't use a common HX711 board with a 3.3volt-logic processor.

Adding a "directly", or "without level changer" would be more exact.

[Wawa]

No, you shouldn't use a level shifter.
You should cut some traces, and power the logic part of the chip from 3.3volt.
Leo..