Problem with Load cell

i am working with CZL601 load cell and HX711 amplifier.They are connected to the arduino through A0, and A1 pin.
I am powering the load cell through a separate 9V,1A adapter.HX711 is powered froim the 5V of arduino.

I am not getting any correct readings.Mostly i am getting readings in the range of 1g to 10g. Sometimes i am getting even negative readings.I tried interchanging the A+ and A- connections on the HX711 but of no use. Can anyone help me to get the correct readings?

If you power the load cell from 9volt, then the bridge outputs are 4.5volt.
That is outside the common mode range of the HX711 (AVDD -1.3volt).
You must power the load cell from the reference voltage provided by the HX711 board.

Thanks for your quick reply.

I have already tried connecting Red and Black wires of CZL601 to the E+ and E- of HX711.Then also the output was in the range 0.1 to 0.9 and even sometimes negative.Even when i apply some force on the load cell, no significant variation was shown. Also when no load was kept on load cell it was returning some varying values.

Then I found out that Excitation voltage of the CZL601 is 9V.That's why i connected it to 9V adapter.

The HX711 can't work with a higher exitation voltage, and might get damaged if you try.

According to the datasheet:
Red = +E
Black = -E
White output to -input
Green output to +input

Measure the exitation voltage with a DMM. It should be ~4.3volt for the HX711 modules I have seen.
Measure the voltage between +out and ground, and -out and ground.
Both should be ~2.15volt, with very little difference between them.
Post voltages, a picture of your setup, and the code.


Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom..... :slight_smile: