Originally posted by srspinho


I still have problems to make the 16F877-20 and the 16F877A working. I have to touch the PIC with my fingers many, many times to make it working ! ! ! really strange...
Hi, just noticed this, I had many problems all over the place to do with touching the pic to make it work, with serial comms, LCD etc etc.

It turned out that i did not connect MCLRE. it was floating. so it never worked untill my static charge from my fingers pulled the pin high. Also check that other main pins arnt floating. (by main i mean not output/input pins.)

capacitors from +V to Ground near the pic also help. They basically filter out noise from the powerline/regulator. 100nf usually do the trick



phil