"arduinize" a weighing scale I bought from amazon

Hi guys,

I bought this from amazon https://www.amazon.com/gp/product/B07HSZL9RC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

the problem I have is that i doesnt have the right precision. I want it to count screws, but it only counts in 50 gram increments (despite it having more decimal places than it needs!)

anyway i cant return it because it's been past the return period.. so I was thinking I'd remap the load cell wiring into an arduino.. looking at the hx711 board to hook it up to. Do you see any potential issues with what I'm trying to do?

It wires up the same way, and I just need to recalibrate the code right?

thanks so much in advance!!

This is a 300kg scale, and 50gram is 6000 counts.
I doubt you can get a high enough resolution from that device to measure screws (assuming average/small size).
Better buy a scale that matches your requirements,
Leo..

is this 6000 count a physical limitation of the load cell? so it doesnt matter what kind of controller i hook it up to, it still wont achieve the precision I need?

Notwithstanding the counts, this is more of a physical limitation - friction in the bearings and supports would likely be comparable with the weight of the screws - mind you, you did not specify whether these are small screws or large and heavy bolts!

Hi,
What mass range and resolution are you looking for?

Tom.... :slight_smile:

heyarn:
is this 6000 count a physical limitation of the load cell? so it doesnt matter what kind of controller i hook it up to, it still wont achieve the precision I need?

Mechanical systems don't have that precision, there will be significant change in response with temperature,
mechical hysteresis, and creep, all limiting the resolution of a load cell. With accurate temperature control and
exotic materials you might be able to do much better, but that's orders of magnitude more expensive.

The actual range of movement in a load cell might only be 0.5% in the first place, 1/6000 of that is basically
1ppm strain.

Rather than try to make the scale you have do what you want you are better off buying a scale designed with your objective in mind. They are commonly called a "Counting Scale". What you have simply put is not going to work well. A Google of counting scale will give you some hits to work with.

Ron