My Mattel Football hack (made the 'screen' larger)

Rik

This was mentioned in another thread, and someone wanted to see pics of it... This was originally a working Mattel Football, but a couple of the LEDs had been damaged and no longer worked (once you touch one, it's toast... But that's how I got it). So I figured it would be fun to try to make an external display for it. I meant to make a 'nice looking' one eventually, but I wanted to see if it work first, so this was my prototype (and the only one I ever made). After making the board, I thought it would be funny to mount it in the handheld game and carry it around at Classic Gaming Expo playing it... Got a lot of fun comments on it...

Here's the front, just after turning the game on, ready to play:

And showing the score when pressing one of the score buttons:

And the back side with all the wiring... Shocked

Another thing I thought of doing was replacing the LEDs with the tiny surface mount ones they make these days... Maybe bright blue or white, just to be weird. Mr. Green

See this thread:
http://www.handheldmuseum.com/forum/viewtopic.php?t=1752
to see how the professionals do it... Cool

Rik

nicknicknickandnick · Posted: Sun Jan 22, 2012 2:40 pm Post subject:

lol, that's larger alright, more so than I expected!

OK now I have an image in my mind of giant lights on a real football field hooked up in that manner, and someone up in the stands playing it.

slydc · Posted: Sun Jan 22, 2012 8:04 pm Post subject:

Cool!! You finally posted some pictures of your Mattel Football mod. Very Happy

Looks even bigger than i imagined and for a prototype, hats off! Wink

I was going to mention if you would ever do a better display/casing
of your mod but after reading/seeing the over-sized Mattel Soccer
that you recently got, i think you'll never going to finish it which would
be a real shame. Crying or Very sad

Just a question: do you use a 9v battery or a 9v power supply since
the big display uses bigger LEDs ? If you use a 9v battery, how long
does it last ?

So many questions & projects, so little time... Wink

--- Sly DC ---

blanka · Posted: Sun Jan 22, 2012 9:35 pm Post subject:

With other colour LED's be careful that the voltage is different, and at higher brightness the current can be higher. The current limiting resistor (is it on the board or inside the chip? if there are many similar resistors on the board, they might be outside the chip) has to be changed to match your LED. What value do they have now?
For example a red LED works between 1.5-2V, where a blue or white one needs aroudn 3V to operate.

Rik · Posted: Mon Jan 23, 2012 12:33 am Post subject:

blanka · Posted: Mon Jan 23, 2012 2:01 am Post subject:

Blue or white leds might not work at all at 1.5V.
Guess they are matrixed. So they either have a common anode or a common cathode. That would allow 1 resistor per group. But the resisters might as well be inside the controller. In that case, you can use optocouplers to switch higher loads, while maintaining a regular "LED" balast to the game itself. It also allows for a complete independant circuit.

Rik · Posted: Mon Jan 23, 2012 11:14 am Post subject:

slydc · Posted: Fri Jan 27, 2012 10:14 pm Post subject:

I was thinking for using blue, green, etc...LEDs, why not make a small voltage "booster" circuitry with some few transistors ?

For each micro LED on a board, boost the voltage with a 2N2222 or 2N3904 ? Just a thought here since i do this to boost the video signal or invert it for old video game systems.

bomberpunk · Posted: Mon Jan 30, 2012 12:35 am Post subject:

wow, it looks like the numeric display was a complete pain in the rump. great job!
_________________
cheers,
bp