Measure current and voltage via ADC

[powermosfet]

Hi,


How to measure current and voltage using microcontroller ADC input.

voltage range is up to +11v and current is about 5 amps.

I use a voltage divider to get the voltage


Vi=11V
RA=1k2
RB=1k

Vo=RB/RA+RB*Vi  -> with about .2 error

are there any better ways to protect the microcontroller input?


thank you.

[Erwin Ried]

Have you seen http://www.ebay.com/itm/5A-range-Current-Sensor-Module-ACS712-Module-NEW-/130704791796?pt=LH_DefaultDomain_0&hash=item1e6e9cd8f4 this kind of modules?

I bought ones but I never used them (I am using a small coil with a TA-220) to do the same