I am just getting started with PSoC's.
I am trying to read in a sine wave that is +/- 1V using ADC (I output the signal using DAC after I do some calculations on it so that I can get ready to do feedback control). I am having trouble understanding how to wire and reference the signal to correctly handle the negative portion of the sine wave. I am generating the signal with a function generator and reading the input and output using LABView and a DAQ card with breakout board. If I simply hook up the ground of the function generator and DAQ card to Vss, I get fairly clean signals, but the output of DAC is cutoff below 0.1V. I think that makes sense (the DAC output is actually shift up 0.1V, so the output is the top half of the sine wave from 0.1-1.1V). If I change the ground of the function generator/DAQ card to port 2-4 (external AGND) there is very little change (a tiny bump toward the negative portion of the sine wave develops, but it doesn't go below 0V). I also setup a voltage divider between Vcc and Vss. If I connect my function generator/DAQ ground to this 2.5V reference, I get a sine save that is going from +/- 1 V, but the output of the PSoC DAC is very noisy. Should I be going about this differently? Are any of these approaches close to the right way to do this? When it is all said and done, I want to be able to input and output sine waves as well as DC (step) inputs. Any suggestions would be appreciated. I have tried looking for entry level reading material on this subject, but haven't found any. So, I would appreciate references to good starting level training material for ADC and DAC as well.