Potential HHV kits for next year.

[DCFluX]

PCB: 4.4" x 2.5"
Microcontroller: Atmel AVR ATMEGA8515L
Power plant: CR-123 or 3x "AA"

Solder joints: 402 (all through hole)
Estimated build time: 2 - 3 Hours

[KillerSpud]

Re: Potential HHV kits for next year.

That looks pretty awesome, simple but big, and with tonnes of possibilities.

How do you plan to address each LED? Charliplexing? Buffers?

The ISP header is an obvious must, but what about rigging something for a bootloader?
FTDI onboard? or off board?
A separate ISP kit is an option too (branded with Defcon 19 of course).

[lexxmac]

Re: Potential HHV kits for next year.

I assume the massive number of individual LEDs is for soldering practice, correct (instead of LED matrices)?

Also, how are you getting around using current limiting resistors without losing the ability to address each LED individually?... or are they just on the back and not visible?

[willasaywhat]

Re: Potential HHV kits for next year.

Reminds me of this: http://blog.makezine.com/archive/201...ol_shield.html

[DCFluX]

Re: Potential HHV kits for next year.

It is a charlieplexed 7x24 matrix. There are no resistors. When driving LEDs I/O pins that have CMOS construction tend to become 15-20mA current sources. Also this varies with LED color and battery voltage. LEDs also can withstand higher current in pulse mode, like 70mA, but only 20mA constant on.

As long as high mCD LEDs are used the image quality is pretty good. My prototypes used junk 10-20mCD LEDs that I think I paid $2.00 for 200, so when all the column LEDs are on such as on a "T" the line is considerably dimmer than the dots because the each 8 bit port is limited to 80mA. Not a perfect design, but it does have function.

Every single pin of the microcontroller is presently used, except the oscillator pins, which I can't assign, so no room left for serial I/O. Its one of 2 micros in a socketable package that has this many I/O lines.

To program people can build the sample electronics LPT programmer, only need a DB-25 and 4 resistors. Of course finding a computer with a LPT port is a challenge these days.

[KillerSpud]

Re: Potential HHV kits for next year.

To program people can build the sample electronics LPT programmer, only need a DB-25 and 4 resistors. Of course finding a computer with a LPT port is a challenge these days.

I would be willing to bet that there where no lpt ports at the entire con outside the musiem.

Even serial ports are becoming few and far between.

Maybe I can arrange somethingwith SFE or batchpcb for a kit.

[DCFluX]

Re: Potential HHV kits for next year.

I am currently working on a second draft.

[bombnav]

Re: Potential HHV kits for next year.

I would be willing to bet that there where no lpt ports at the entire con outside the musiem.

Even serial ports are becoming few and far between.

Maybe I can arrange somethingwith SFE or batchpcb for a kit.

I always bring a older laptop with both... you just never know what the con will throw at you.

But USB is always the way to go if possible.

[kampf]

Re: Potential HHV kits for next year.

KillerSpud: There will be more than a few serial port toting Dells showing up at you-know-where in the next month or so.