Halfway done with the rat lining for the PCB. A rat line is basically a visible line while PCB drawing that indicates net lists. A net list is just a list of all the pins and connections that are connected together. After I rat line I can lay down the traces.
The FPGA sees the display as a 64×64. This is due to I/O limitations. The odd rows are on the left and the even rows are on the right. So row 1 and 2 really make up the physical row 1.
Almost done with the PCB for the 32×128 DMD. Just finished placing all the components. Just have to rat line everything and trace it up.
Here is a Atari 2600 Cart PCB. It is the basic 2K/4K EEPROM. I don’t have the PCB files uploaded yet but you can download the CAM files. This is free for anyone to use, sell, and/or distribute.
I will be uploading the PCB files in a week or so when I get back from my vacation. I use FreePCB. I will be uploading my custom footprint library as well so people can open the files.
The WS2801 is a 3-channel constant current LED drivers that is designed for controlling chains of RGB LEDs. The IC is controlled by a 2-wire serial control scheme that allows multiple WS2801 to be chained together. You can find the WS2801 in the link below. This demo code basically shifts out 24 bits (8bits per color) using a 2-wire protocol. This code only works for one WS2801. There is a object designed for multiple WS2801 already in the propeller OBEX. That design uses too many resources for use on my pinball machine so I wrote this to use as little resources as possible (no new cog).
The idea would be to have the WS2801 PWM a set of mosfets which would in turn be connected to the string of LEDs. This way you could light up a bunch of RGB LEDs without allot of CPU time taken from the Propeller. The Propeller only has to mess with the WS2801 when it needs to change the PWM signals.
Where to buy the WS2801.
Demo Driver