We are trying to integrate a load cell on a FRC robot. We started with the RB-Onl-38 shield on an Arduino. After some testing, we realized that since our control system has a built in ADC, the Arduino is unnecessary, so now we are interfacing the RB-Onl-38 shield directly with our control system (basically using the shield as an instrumentation amplifier). This works fine, but as mentioned in by Brian Daouas in the “Interfacing a load Cell With an Arduino Board” blog post, we are running into the problem that the filter on the board is limiting the range of the output voltage to somewhere between 1.25v and 1.8v. The load we are trying to measure is in the mid range of the load cell, so we are right on the upper limit of this voltage range (our load cell is always in compression). We realize that we can lower the gain on the amplifier to bring the voltage into this range, but that will come a a cost to resolution.
Is there a better amplifier board that we can use that will output an analog voltage closer to the entire 3.3v range of voltages?
Thanks,
Kenton Cabiness