Fred,

easiest way is use 1% tolerance resistor divider with 5,1 v ziner diode 
connected
to ground to protect pic. on top of  ziner add ceramic and electrolytic cap.
this means when your battery is 14,4 v  pic will get 5 v or you can set 
to any voltage.
more expensive way is to use leaner opto-coupler this is good for noise etc.

Andre Abelian




fred jones wrote:

>
> Hi all,
> I'm sure this is an easy question for many of you so I hope I don't 
> get flamed.  I searched but can't find the answer in the archives 
> although I'm sure it must be there somewhere.  This is not my strong 
> point so I thought I'd ask for help.
>
> I am building a device that will run off of a 12V gel cell battery.  
> It will use a 16F877 PIC powered with a 7805 regulator.  I'd like to 
> be able to read the voltage of the gel cell and display it on the 2X16 
> LCD display.  I'm sure I can't connect the 12V batter into the A2D of 
> the PIC but I'm not sure what the proper method would be.  Any help is 
> appreciated.
> Thanks for your time,
> FJ
>
>

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