strain gauge _ wheatstone bridge_Hx711

[afshin_g]

I'm trying to read voltage from a strain gauge (Omga brand) by using a wheatstone bridge.
I'm using Hx711 for amplifying. I double checked everything but every time I received strange outputs.
Sometimes the value increases and sometimes it decreases. Also, when I'm bending my strain gauge the values change out of a usual trend of increasing or decreasing.
I replace strain gauge with a resistor to check whether the strain gauge is working or not ,but still the same problem is remained.

Using HX711.h library and Basic example.

Output with 4 resistor:

HX711 reading: 492728
HX711 reading: 775380
HX711 reading: 994679
HX711 reading: 1106813
HX711 reading: 1278996
HX711 reading: 1377663
HX711 reading: 1471010
HX711 reading: 1563120
HX711 reading: 1619820
HX711 reading: 1676008
HX711 reading: 1743565
HX711 reading: 1790578
HX711 reading: 1810853
HX711 reading: 1844689
HX711 reading: 1896701
HX711 reading: 1900388
HX711 reading: 1910008
HX711 reading: 1965770
HX711 reading: 1973091
HX711 reading: 2005506
HX711 reading: 2009966
HX711 reading: 2010314
HX711 reading: 2004080
HX711 reading: 1987136
HX711 reading: 1956935
HX711 reading: 1962799
HX711 reading: 1927443
HX711 reading: 1884326
HX711 reading: 1864398
HX711 reading: 1868141

[MarkT]

Ordinary resistors will have too much thermal drift, you need 0.1% low-tempco resistors
or better ideally, 1W or above (to reduce self-heating). In a real strain guage the 4 elements
are overlapping and thus have extremely good temperature matching, and glued onto a
lump of metal (and thus heatsinked).

In a bridge circuit like this variations are measured in microvolts, so high precision is needed.

[johnerrington]

A schematic would be great

How to make a schematic you can post

and post your code too please - between code tags.

[Wawa]

Could be one of the HX711 boards where the E- ground connection is missing.
See post#23 here.
Leo..