> 
> 
> 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.
> 

Non-standard schematic conventions make it a bit hard to read.  Contrast and size of some of the text on the background makes this one hard to read.

That said here we go:

1) RB6 / RB7 are the programming and debug pins.  Yes, you can use them as I/O but you will loose your ability to use them as debug pins.  Furthermore, you call out RB6 on your oddly shaped PIC twice.  

2) Component values not labeled in many cases.  What FET/MOSFET are you using?  Where is the value for the high and low side drivers?  Etc.

3) No component numbering, again this can be a cause for confusion.  U1, U2, D1, D2, R1, etc are quite helpful.  -- Wait I retract part of that statement.  I found some components are labeled but so small they are hard to see.  And in some cases there are nets running through the text.  And finally some have a "number" but most just have "?".

4) Non-standard component shapes.  "L" shaped PIC is a bit odd.  Use buses to show large groups of lines.  Sometimes it helps to make things like microcontrollers in shapes other than a simple rectangle or to split them up into multiple shapes.   Or to group the pins by function instead of numeric order.   But in this case I think a simple rectangle with buses to show the signal groups would have been more readable.

5) Power?

6) Ground?

7) Supply bypass caps?

8) Reset component values?  Not familiar with the 16F887 but in general, for the "newer" PICs (16F and 18F) I was of the impression that a single pull-up resistor on MCLR/VPP is OK for the reset if you also have the POR bit set.  For a production unit I'd think a bit more about the reset vs power supply turn on but for hobby and play seems OK.

9) Pins for the 7-seg?  Are you going to use something like a 74HC595 and SPI bus to control them?

10) I've never been a big fan of the weak-pull ups in PORTB and unless I'm really pressed for power consumption I like a nice stiff pull up resistor.  Again, _personal_ preference but I generally use a 47K for pull ups on a 5V design unless I need to minimize power and then I go through the exercise of computing currents versus expected duty cycle of the signal vs. input current HI/LO logic for the given PIC and its operating environment.  For the one you have indicated on E1, what value?  

11) What is hanging off of E2?  

12) Internal oscillator?  If nothing else, a quite note in the corner of the schematic about that.  

13) Un-used inputs on your driver chips should probably be tied to ground.  Maybe through a resistor so you can use them later if you decide you want them.  

14) If you switch to a common cathode 7-seg you could use your two spare high side drivers instead of the discrete FET/MOSFETs shown.



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