Measuring DC current

[mitchf14]

I am using a 0.1 ohm resistor with the adcin on my pic measuring the voltage drop. Which works great they only problem is that the pic can only read up to 5vdc and I'm calculating the current from a 12vdc battery, which after the 0.1 ohm is around 11.80v. I tried running it trough a voltage divider but the added resistance of the divider makes my calculations very off. Is their a way i can buffer that resistance out so my pic will read a accurate reading.

[mjmccarron]

I use this part for all of my current measurement. It works off the 5v supply and gives a nice 0 - 5v feedback that is easily read by the PIC.
--Mike

http://www.allegromicro.com/en/produ...5/0755-130.pdf

[Gusse]

Put your sense resistor between load and ground. Then you see same current but DC voltage is only 0.2v. This is the most common way to measure current with sense resistor.