A/D conversion problem with 18F2455

[skimask]

I am applying a sinusoidal signal with the offset voltage of 2,5 volts and an amplitude of 5 volts to PORTA.0

1st problem - A/D inputs on a PIC don't work with negative voltages. See Post #4.

Its frequency is 1khz. So, it varies between (0~5) volts. I want a digital output coming from PORTA.1

Do you mean you want to output, on A.1, a serial output representation of the analog input on A.0?

But however, so far I get 5V(DC) from PORTA.1

That's good because I don't see anything in your program that says to change the output on PortA.1 other than it's initial setup.

By the way, I use 10 bit ADC and the converted digital values I want to get serially every time when the conversion is over.

And again, I don't see any serial output commands.

I used ADCIN 0,W0 which reads the values from PORTA.0 and writes to W0. After that, if you look at the code you can see that I am trying to get those values with delay(PAUSEUS).

And again, how do you plan to see this output? Serial output? LCD? There aren't any in the program.

I am using 18F2455 and could not find much relating A/D Conversion with it.

You're kidding me right? Section 21 of the 18F2455 has no information in it that you can use?

I need working ADC.

You've got a working ADC, what you need to do is to get it to work FOR you. I think what you need to do is play around with the PIC and PBP first. Get an LCD working, get a pushbutton or something working with it...then, hook up a POT across an A/D input pin, then display the value of the POT, doesn't have to be resistance, doesn't have to be voltage, doesn't have to be anything in particular, just display a number that corresponds with the position of the POT as you turn it. Then when you get that working, you can easily work on reading a sine wave.

And besides, even though the A/D on a '2455 is rated for 100ksps and the PIC can run at 48Mhz, you won't be able to get any useful DSP out it. Not enough horsepower under the hood.