144 LED Games Console Project

[aberco]

Just found this great project and was really excited!

I have just finished drawing a PCB for it, with two possible versions: one with 5mm leds and the other with large 10mm leds. It's all using surface mount components, but they are not that hard to solder (in fact it is easier!).

The matrix is now driven my a pair of PNP/NPN or P/N channel mosfet in order to boost the brightness. Since the multiplexing routine slice the display in 18 increments, it is possible to boost the brightness by feeding more intensity in the LEDs this way. For simplified rooting of the board, I also changed the pin allocations for the PIC. The program will need to be modified a bit to account for that, and for the inverted signal needed to drive the base of the PNP transistors.

The board has an integrated regulator (7805) and also an optional DB9 for serial communication with voltage converter (using a simple transistor, not a full MAX232). It also feature an ICSP connector, so it can be easily reprogrammed for other projects.

Need to check a few things, but I'll be happy to release the gerber files here. Also I'm planning to make an order from my PCB manufacturer, so if anyone is interested I can sell spares for a reasonable price.

[Art]

Nice
Would love one if I had any confidence in soldering smd parts :O

[aberco]

I'll send you some, here's a video I made for soldering SMD's:

http://www.mactronique.com/showArtMn...11&zone=movies

[Art]

Lol, nice, but electronics is not so much a love of mine
I only did what I had to do to write software for it

One day I'll write an interrupt driven clock for it using DT's elapsed timer.
Didn't quite have it figured out at the time.

[aberco]

A clock would be nice, should not be too hard to write as I've seen some implementation somewhere on this forum. Darrel's routines for interrupt are very simple to use, so you could use a timer interrupt to derive your 1Hz signal. I have built some clocks too, but they all use I2C RTCs (so that they can keep time while power is off). Newer PICs have built in RTCs too, so that may be something to look for... but I think they require an external 32.768kHz xtal for Timer1 which is not planned on the PCB layout.

Keep in touch! I'll get back in the forum when I get the PCBs manufactured and your code modified. I'm a bit the other way around, software is not my thing... I'm actually quite impressed by the routine you wrote for this project!

[Cobra_Phil]

I did not read the whole thread, but have you seen these yet?
http://www.sureelectronics.net/goods.php?id=1095

32x16 Red/Green LED's gives you three colors.
Very easy SPI interface. I have 3 of these linked together using just 3 SPI control signals and 3 Chip Select Signals.
I have seen other link upto 8 of these boards together. Here are a couple of links.

[aberco]

There are many LED drivers IC around. The nice thing here is to use only off the shelf, easy to find transistors to drive the matrix.

I have a large 16x16 chainable LED matrix in project using PWM LED drivers from TI, also interfaced via SPI.