Quote Originally Posted by Mike, K8LH View Post
Do you think it might be possible to add 2 (or more) bits of precision to the DAC?

Code:
Interval  #1  #2  #3  #4
     DAC  00  00  00  00  -> 0.00v
     DAC  00  00  00  01  -> 0.04v
     DAC  00  00  01  01  -> 0.08v
     DAC  00  01  01  01  -> 0.12v
 
     DAC  01  01  01  01  -> 0.16v
     DAC  01  01  01  02  -> 0.20v
     DAC  01  01  02  02  -> 0.24v
     DAC  01  02  02  02  -> 0.28v
 
     DAC  02  02  02  02  -> 0.32v
     ........
This must have slipped past me - I'm not understanding what you're getting at?

I was actually wondering myself whether it's possible in practise to squeeze another 2 bits of effective' resolution by switching the fixed voltage reference supply into the DAC resistor divider chain (ie feed 1.024V in for the first 32 voltage level steps, then 2.048, then 4.096V) - it might be a bit spikey (due to the FVR switching voltages), but if not that should mean we can squeeze 7 bits out of the PIC's DAC pin.