Question on IO ports

[Charles Linquis]

Why don't you just start with a PIC with more pins? You could have the I/O ports *AND* drive the LCD with the LCDOUT command - without any external parts.

[Jerson]

If you're planning on using one of those expanded ports (74LS164) to write to the LCD, its a long shot. If you want to write to the LCD as shown in your diagram using RA0, you could look at either SEROUT (RS232) or SHIFTOUT (Parallel - Serial) commands in the manual. Which one to use depends on what your LCD understands. I've never used a serial LCD, so I cannot say.

[studysession]

If you're planning on using one of those expanded ports (74LS164) to write to the LCD, its a long shot. If you want to write to the LCD as shown in your diagram using RA0, you could look at either SEROUT (RS232) or SHIFTOUT (Parallel - Serial) commands in the manual. Which one to use depends on what your LCD understands. I've never used a serial LCD, so I cannot say.

Thanks -
I am just trying to do something other than the example in the book. I just randomly chose the LCD. From your statement I now understand. I just want to make sure I can do something else than just turn on or off LED's. Trying to figure out how - like maybe read a value from a pin or something else maybe.

I did the lab in the book which was turning on and off the LED's. I have a good handle on that but not using it for anything else.

Thanks

[studysession]

OK - I am having some issues here. I am trying so hard to understand using this 74LS164 chip.

How would I modify my code above if on one of the lines within the serial routine, that I wanted to read a value if a button was pressed and pass it back to the main program?

Thanks