Quote Originally Posted by menta View Post
Yes, its 16f877A, my mistake.
I tried connecting the MCLR pin to the +5v but it didn't help.
It also didn't help using 2x 7805.
Its very strange because I have another circuit just exact to this one but using a 887 on a demo board.
BTW, if I use the programmer voltage output (just + and - ) and connect them to the circuit its also working ok.
Are you using the same program between the 887 on the demo board and the 877A in the circuit? If so, it won't work.