Dear PICsters, 
I have just finished a little PIC project, and I want to know whether or not it would 
be appropriate to send the full listing which is about 40K to the PIC List. 

I do not currently have a web site that I can post the information on, otherwise I would 
simply do so and post the URL. 

The code is heavily commented, so it might be useful for beginners and others to look 
at to see an example of a complete project. The assembly code comments include info 
on the actual hardware (very simple) and PIC pinouts used. 

I also have the printed circuit board layout and schematics and parts placement 
diagrams all in one AutoCad DWG file, for those who have access to AutoCad. I could 
convert this to DXF format if that would allow more people to use it. 

Here is a description of the circuit and software: 

The hardware consists of a PIC 16C84 or PIC 16F84, a 16 key xy matrix keypad, 
a 4.00 Mhz resonator with built-in caps, a red and a green LED, 2 330 ohm 
resistors, 1 4.7K resistor, 1 10K resistor, a printed circuit board, 10 pin header, 
one general purpose NPN transistor such as MPSA05, and one 5 V PCB DPDT Relay. 

The PCB design also has a general purpose 5 volt regulator circuit on it 
to allow operation from a 12VAC wall-wart type transformer. This part of the 
circuit uses 4 1N4001 (or greater) diodes, a 220 ufd cap, a 10 ufd cap, and 
a 5 volt regulator such as a 7805. 

The keypad used is made by Grayhill and has an 8 pin connector on the back. I believe 
that Jameco has the same keypad that I am using, but with a 9 pin connector 
(unless their catalog is in error and it is really an 8 pin connector). The 
keypad has 0-9 and also LOAD CLR ENT RUN and UP and DOWN arrows. 

The user gets the unit's attention and synchronizes the program by hitting the CLR 
key. The CLR (CLeaR) key is handled special, and ANY time the CLR key is 
hit, it will cause the program to synchronize and begin regular entry. To 
indicate that a key is being pressed, the normally-on RED LED will go off 
for the duration of any keypress. When the CLR key is released the GREEN LED 
will flash once to indicate that the program is synchronized and ready for 
regular input. 

The user can now enter any one of eight valid entry code sets. Each entry code 
may consist of from 1 to 8 digits, though the factory Mastercode will always 
be an 8 digit code. The user may use the digits 0-9 and the LOAD, UP and DOWN 
keys as part of the entry code. The CLR ENT and RUN keys may *not* be used 
as part of the entry code, as they have a special meaning. 

After entering the user-code, the user will normally press the ENT (ENTer) 
key. If the code entered was a valid code, then the red and green LEDs will 
flash back and forth for ten seconds. During this time the relay will be 
energized, and it's contacts may be used to activate a doorlock mechanism, 
for example. During the 10 seconds, the user may press and hold any key 
to extend the on-time of the relay. As soon as any key is *released*, 
the on-time of the relay will be immediately terminated. Thus the on-time 
can be made longer or shorter as desired. 

There are two special codes known as the Factory Mastercode and the User 
Mastercode. The Factory Mastercode is hard-coded into the chip and cannot 
be changed. The User Mastercode can be changed by the user. 

Whenever the user enters either of the Mastercodes, he/she may then hit 
the ENT key to activate the relay, OR they can hit the RUN key to enter 
the special MASTERCODE MODE. In Mastercode Mode the user can change or 
delete any one of 6 user-codes, and change or delete the User Mastercode. 

After entering either Mastercode and the RUN key, then the user should 
enter a single digit from 0-6, followed by LOAD and then the 1 to 8 digit 
code desired, and finally the ENT key to terminate this mode. 

If LOAD is followed immediately by ENT, then the desired code set will be 
deleted instead of entered. 

The load sets are 0-6. 1-6 represent regular user code sets. You might 
assign a different code set to each member of your family. (People like 
Andy Kunz will have to re-write the code to allow packed nibbles instead 
of the byte method I used. That would allow 14 user-codes and two 
mastercodes). 

Load set 0 is special. This will actually load in the User Mastercode. 
I strongly recommend using an 8 digit code for the Mastercode, but 
I wrote the program so that it allows any code from 1-8 digits in length. 

***** 
No attempt was made to make the code super-efficient. It occupies just 
a little less than 1/2 K of ROM space. So there is lots of room for 
others to add additional bells and whistles. There are two i/o ports 
left unused in the original design. 

There you have it, a short description of the KEYPAD PROJECT. 

So, should I post the 40K MPASM file to the PIC List, or would that be 
upsetting to many? If I post it, should the code be in the main body 
of an e-mail, or should I make it an attachment? 

I will wait until there are enough responses to arrive at some consensus. 

Hope this helps 
Fr. Tom McGahee