Microcontroller based Function Generator

hi friends what about Microcontroller based Function Generator project using some AT89c2051 or higher an DAC 0808 ,and LM741 for c/v conversion to generate Sine, square, triangle, and sawtooth waveforms , and it also have some capability like
(1) To display the status on LCD whats going on at output (like what waveform at what freq)
(2) Also it can produce variable frequency by pressing up and down button then start

all we need is a DAC..
wow.. nice one TPS

i have done this before with PC Parallel Port with same circuit as playing .wav file through LPT terminal

oww.. i have DAC0808 with me..

I think all you need is values that are to be sent to the dac.
We need to think about the features that can be possibly added to this project. because generating waves is not a big deal...

how to generate sine wave ? i have used loop in Turbo c program (LPT version)

what kind of loop?
you need to send some values to your parallel port that suppose to give you a shape of sine wave.. I think whatever you did in Turbo C same is going to be done here..

are you sure that 741 is fine for generation of sine wave? I heard that response is not so when when it comes to pure sine wave! I have a link where they have used R-2R network to generate a pure sine wave.. all the waves they generated looks so cute..
i will give you the link when i find it..

741 is to convert output od DAC (Current form) into voltage form . also we can add Amplitude controller. in LPT version i need to convert Degree into radios then putting its value in sign formula then getting its 8 bit value then LPT then DAC then 741 ...then CRO

check out this website.. they have given information on generating sine wave also.. they have given possible reasons why its not recommended to use LM741.
http://www.avr-asm-tutorial.net/avr_en/AVR_DAC.html

nice one :-) r -2r is to replace DAC but i think it would be more smart if our Function generator have some capability like
(1) To display the status on LCD whats going on at output (like what waveform at what freq)
(2) Also it can produce variable frequency by pressing up and down button then start

As i Said before :-)

oww.. yes.. we can do like making a variable amplitude o/p using transistor switching of inverting i/p on opamp. i think that will vary the amplitude.. if we use it in differential mode... am i right?

How can we know the frequency? we need to feedback the o/p to our controller's i/p to make it read the frequency. Also is it possible to somehow make use of comparator of AT89C2051?