I'm interested in making a load cell scale using an Arduino so I can program special features that currently available scales don't have.
Any thoughts on best way to get high resolution data to an Arduino microcontroller board?
AD7730 chip, or Instrumentation amp to A/D converter?
Anything readily available such as load cell in and serial data out?
Most of the ready made load cell indicators I've been looking at have either
20 bit or 24 bit A/D but only give 10,000 or so steps of resolution, I guess because of noise?The features I want to be able to program in are things like reverse taring, where you weigh a full container, select reverse tare, then empty the container, and scale calculates tells how much product was removed, I think this is also called loss of weight weighing or something like that.
Another feature is I want to be able to calibrate with homemade calibration weights. The idea is that I will come up with a weight heavy enough to calibrate in the range I want, then take it to work and have it weighed on an accurate calibrated scale, stamp the actual weight on it and it's good enough for my purposes. So far I haven't seen a scale that will let you calibrate with something like a 100.123 pound weight, for software it isn't a problem.
The best feature I want is to be able to add is using one scale for multiple weighing platforms, having the calibration data stored in non-volatile memory (eeprom, flash). This way I can use the scale display for reloading scales or weighing machinery just by selecting the scale I'm currently plugged into.
Thought maybe some here may know of a good way to get load cell or strain gage signals into a microcontroller like an Arduino.
Thanks
RogerN