I'm making an electronic portable Connect4 game that will run on 
batteries. It started out as a project for college but now I'm just 
doing it over the Summer for fun.

The game consists of a matrix of bi-colour LED's which represent the 
chip places:

    x   x   x   x   x   x   x
    x   x   x   x   x   x   x
    x   x   x   x   x   x   x
    x   x   x   x   x   x   x
    x   x   x   x   x   x   x
    x   x   x   x   x   x   x

The display is multiplexed, only one column is ever lit at a time. In 
each column, all the LED cathodes are common, and the common cathode 
goes to a low-side driver which is controlled by a PIC pin.

Under each column there's a push button. You press the push button and a 
chip falls into that column. Player 1 has green chips, Player 2 has red.

I've decided to use the three-pin LED's that are called "tri-colour", 
but I'll only be using them as bi-colour (i.e. I won't ever have both 
colours lit at the same time).

I'm using the PIC16F887 this time around (the 40-pin DIP kind) and I'm 
using the Pickit2 to program it.

The 887 has 5 ports: A, B, C, D, E

Port B is the one that has internal pull-up's so I think it's the 
natural choice for the push buttons. I'll have 7 push buttons but 
unfortunately I can only use 5 pins on Port B because I need RB6 and RB7 
for hooking up to the Pickit2 (my board is going to have a header for 
hooking up the Pickit2). For the final push button, I use the RE3 pin in 
conjunction with my own pull-up resistor.

For driving the rows, I opted for port D because it's pretty much just 
an I/O port. I needed more pins for driving the rows so I used A0 thru 
A5 also.

For driving the columns, I opted for port C.

Port E is the "save the day" port that just cleans up the mess of not 
being able to use other pins such a RB6 and RB7.

Here's a link to the current schematic of my project, I'd appreciate if
you'd take a look and see what you think, give me advice! :-D

http://users.imagine.ie/toe/scoth.pdf




-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist