Dot Matrix Business Card

Step 5 Programming

The next step is to put the dialling program into the chip. If you have bought the PIC Kit 2 programmer, it has everything you need with it. Download the MatrixCode.zip file from this page, unzip it and put it in a directory somewhere on your computer - then from within the MPLAB IDE, go to the "Project" menu, select "Open", and navigate to the "main.asm" file. Change the stored messages (around line 115 in the code) to your contact details rather than mine(!) - the messages are spelt out with a series of '1's and '0's - a '1' means the LED is on. If you look closely, you will see my name spelt out with '1's. (You might need to turn your head 90 degrees to see this!) You have complete freedom to make your own characters or symbols, so you could have, for example, a simple animation of a car moving to the left if you wanted. Note that there are four messages - one for each button - you will need to specify the length of each message by stating the number of columns it takes up in the 'MSG1LEN,MSG2LEN...' definitions.

Go to the "Project" menu again, and select "Quickbuild" - check there are no errors, and you are then ready to program. I use a simple technique of inserting a broken-off strip of 5 pins from a strip of 0.1" header pins into the programmer, and then just touching the 5 pins whilst programming. This is a little fiddly, but as the erase or program cycle only takes a second or so, it is quite manageable. The arrow on the end pin of the programmer should align with the top pin of the PCB (NOT AS SHOWN IN THIS PHOTO - WHOOPS!) If you are experimenting, it is well worth soldering the strip of 5 pins onto the board until you have finished your changes. When you are ready to program, you will have to use the separate 'PICKIT2' utility supplied with the programmer, as for some reason, the MPLAB IDE doesn't support programming of the PIC16F57 directly. To do this, you need to specifify the family of PICs ("baseline"), and the particular part (16F57), before loading the Hex file created in the previous step, and then finally programming the chip. If all is successful, you should be able to insert the battery (positive side down), and press one of the buttons to see your message scroll along!