While attempting to set the vref on my DRV8825, the reading starts somewhere around .5 volts then drops continuously making it impossible to set current limit. Is that normal?
From your description, that does not sound like normal behavior. What are you using as a power supply and what is connected to the DRV8825 carrier when you are measuring the VREF? Can you post some pictures of your setup that show all of your connections, as well as how you are measuring VREF?