.025 ohms was just a practical example. In real time, I would use a 25mOhm resistor, and a 1v Vref on the MCP3204. That should reduce the drop significantly, without getting rid of the precision!
What do you guys think of
this
Also, about the inductance-based current sensors, don't you need a circuit to constantly monitor it if you are using DC? Won't only the changes in amperage be shown? This still seems to be quite a simple way of getting a very accurate read of the current consumption! I think that this was of induction-based current sensing is relative, not absolute. This is what I learned when I went job shadowing at SRP. They use donuts, secondary coils for the wire, allowing them to read how much current is passing. Maybe I could do an experiment on a compass near a weak magnet, and this and see if the deflection changes as more power goes through!