Hi
I have problem with hx711 module. After call "scale.tare()" readings from "scale.get_units(10)" oscilating near 0 for a moment and them rise above. How to prevent that rise?
Below picture where I marked 2 calls tare function and rise of readings. My readings oscilating between 0,00007-0,00025 kg, I know it is not much but can i improve it?
Green graph - raw "scale.get_units(5)" in this case
black graph - moving average, array 30 elements
What is range of your scale range ?
There will be some noise and drift around “ zero” , but it will depend on the range of your scale - this appears a tiny amount .
I have 2 load cells joined in parallel, 5kg each. I measure in this case 1kg packages.
So you get readings moving between
5.00007 and 5.0025 kg , pretty good really ...
You might get better with careful or better electronics layout , better quality load cells , but that’s pretty good for hobby parts .
Be interesting to see a schematic and picture of the setup.
Cheap load cells , poor wiring layout , breadboards , power supply, temperature variations ....
If the reading agrees with the permissible error of the load cell, then it is ok. Check the data sheets of the specific load cell.
Put 500 g weight on the load cell and check that the reading is stable with some error which is within the permissible range.
My load cells are very cheap so mayby that's a reason. It's hard to find small good load cells. I have also 15kg Zemic cell and it is much better but to big for my use.
Tryed also exponential filter but it is too slow for dynamic measurments.
Creep and hysteresis are problems with standard loadcells - more expensive units use special steels or
fluid pressure to reduce the effects.
Here there will be a combination of these effects and imperfections of the amplifier/ADC itself.
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