Hi guys I m new to the field. So help me.

I had a small project with 16f877a MC. But its need to touch the ground pin of 7805 regulator to work MC properly.

 

Post your schematic

 

schematic diagram of the power unit

 

Wheres the PIC?

 

I feel your power circuit is too complex and involved. Now that i'm done with opinion:

Is Vdd your "pic power" and is Vss connected to ground?

Also, do you actually need your mclr?

 

pic power to Vdd & Vss ground.


ya I need mclr

 

I don't see anything obvious, but I would roll through your code and ask yourself if every last piece on that circuit is a necessity. I don't personally see why you need the LED and diodes, but I don't know what your trying to rock on the other side of that pic.

 

the led should light when you have power, I like that, keep it. Use a meter or a scope to measure the volatage on the pic pins esp. power and make sure they are correct. Does the pic have a clock signal ( look with a scope ). If you are on a bread board using a crystal do not go above 4 meg hz unless you do not mind fiddling around to make sure the clock is running.

Use a program so dog simple that you are sure it is ok.

Post more of your project.

 

Sounds like a simple oscillator problem.... lack of crystal, resonator or RC, or be device is correctly set in configuration statment.

 

Your schematic will not say much, appart you will never reset your pic with such a wiring.

Post the whole schematic and your code for more help.

Alberto

I agree. totally