Problem with Load cell

Using Arduino Project Guidance
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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?

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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.
Leo..

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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.

4

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.
Leo..

5

Hi,

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:

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