hi!
I'm working on function generator Project , but there is a problem i can't solved .
the problem in the triangle wave like this :

Such as in the picture, the field of My function generator between 5v-3v and the real 5v-0v.
here the circuit :

and Thanks

 

as its a schmidt gate ic, the voltage across C1 will swing from 1/3 to 2/3 of the supply, so thats 3V to 6v output.

 

Best I can tell, the circuit shown shouldn't even oscillate....

 

thanks guys !
Problem solved but after hours of headaches and tests,
here's the schema :

I wish if I can help who faced the same problem

 

Look at this:
OpAmp Triangle Generator

Notice the triangle wave from the 74HC14 is slightly curved and not symmetrical. This is due to the non-linear charging of the capacitor through the resistor.
An op-amp provides constant current charging which gives a more linear triangle wave.