Yigit Turgut wrote:

>>>>Input : 40mv - 111mv Output : 1V
>>>>Input : 112mv - 214mv Output : 1.5V
>>>>(unspecified)
>>>>Input : 280mv - 400mv Output : 5.0V
>>
>>>use an A/D with sufficient bits to get desired number output steps
>>>tied to D/A with same number of bits
>>
>>Hi Robert, the steps Yigit has indicated above don't suggest a linear
>>relationship. If it isn't log either, then something with smarts is going
>>to have to translate

A programmed EPROM. A/D = address. D/A =data for D/A.
A PIC would be easier to 'tweak'.

>>Yigit, can you detail the input ranges and voltage out for each please
>>
>>You haven't said what 'quality' of output voltage (eg PWM ripple,
>>precision) you want and how quickly
> 
> 
> Well deadline is monday.

You're going to have fun meeting that.
School project/assignment?

> Exact values are like these ;
> 
> Input   : 30-57-130-202-270-330-380-422-460-492-520 (mV)
> 
> Output :  0 - 0.5 - 1 - 1.5 - 2 - 2.5 - 3 - 3.5 - 4 - 4.5 - 5 (V)
> 
> 11 values for both.First I will put an offset with a SGA to get 0 for
> that 30mv input.And then I am planning to use a non-inverting
> (probably) LM358 gain amplifier.Since the graph is
> 
> http://img441.imageshack.us/my.php?image=graphprcjt01es8.jpg
> 
> seems like it can be operate -almost- linear.

Quite an odd shape. Something like a brightness correction curve for a lamp dimmer.
Is the output really SUPPOSED to be step wise? That is NOT what your graph shows.
It shows a incremental output for every input value, not a fixed one.

> But of course I do have time to adapt it to PIC and it would be really
> good since I can get precise output with it.

PIC A/D. Use lookup table (or if-then-else tree) to create D/A value to
use in software or hardware PWM to get you a 1 pin output.

Lots of software PWM code out there.

Robert

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist