14 bit ADC for Load Cell | Cypress Semiconductor
14 bit ADC for Load Cell
I'm working on a project to read a load cell. I've fed the load cell sig+/- through the INA125 with an offset to output 0.454V-5V to an analog pin of a PSoC1 CY8C28433.
I've tried using the DelSigPlus and ADCINC with 14bit of resolutions. If my math is right, I should be able to read 5/(2^14) = 0.3mV/div
The resolution I care is more in the region of 2.44mV/div
However, I've run into a problem somewhere. The hardware portion seems to working correctly. Every 1 lb change on the load cell translates to about 2.44mV change at the INA125 output. The PSoC however is not detecting this change at all. To make sure the code was "working" I applied a very large weight (~135lbs) and saw the ADC output a change of 551 counts (difference). The math doesn't seem to match though. Is there a limitation that I am missing? Perhaps I can't sample with 0.3mV/div of resolution?
Thank you for your help.