PIC18F8490 Input issues

[heepofajeep]

Hi, I am working with a PIC-LCD from Olimex. I am trying to simply detect when a pin is HI, but can't seem to detect anything, so I am wondering if someone had any suggestions...

I am appending this snippet to the PIC-LCD test program (& I can program the 18F8490 PIC no problem):

if ((PORTC & BIT6)==1){
TEST_LCD()
}

NOTE: TEST_LCD() is a function provide by the PIC-LCD test program.
I have tried changing the 1 to a 0, and no matter what, I get nothing.

Also, I noticed when the board has no power, if I send a 3.3V signal to RC5, the board will power up, albeit very weakly. This doesn't seem right to me?

FWIW, I am trying to use RC5 in the above code snippet, as this appears to be a free pin on the PIC-LCD board.

When I am sending a signal to the board via RC5, I connecting the power supply GND to GND on the Development board, and +3.3V from the power supply to RC5 on the development board.

Your help would be very much appreciated, I am kind of in a time crunch for a project I am working on. Alternatively, if for some reason I cannot use RC5, other pins that appear to be free on the board include: RC4, RC3, RA5, & RA4-- I only need 2 functioning Digitial I/O pins for the project I am working on.

Also, one last thing, I was wondering if someone could tell me what the pins labeled 'PGC', 'PGD', and 'RST' represent?

Thank you very, very much!!!

 

[Nigel Goodwin]

Also, one last thing, I was wondering if someone could tell me what the pins labeled 'PGC', 'PGD', and 'RST' represent?

They are for programming, clock, data, and reset.

 

[giaosucan]

i am a beginner in PIC ,someone can give me some guide about the schematic of PIC18f4545
many thanks for your help

 

[gregmcc]

giaosucan - have you tried the datasheet from the microchip site?