how to assign voltages using 0-16 hexadecimal numbers

[angiey]

Hi all!!
How to assign the voltages[say 7 to 12v] using hexadecimal values,since i'm using pic microcontroller i have already assigned 4 ports as v1,v2,v3 & v4
and initialized different hex values to these port numbers,so when we press any key it should set to the particular voltages.
Kindly give any suggestion regarding this.

 

[Malek Lamari]

Hi,
use an R2R DAC.
http://www.avr-asm-tutorial.net/avr_gra/r2r_buffered.gif

here more clear image:
**broken link removed**
change the values of the resistors to assign the voltages that you wanted

 

[angiey]

Hi,
Thanks for the information,it was really helpful.
Can you give me some hint that how this values can be stored in the program,as i'm using C code,
and for this i'm using if_else statements, it should be programmed in such a way that when we press
some button it should vary[i.e, voltages should vary].
Thanks in advance.