Drawing power from the Gamecube's controller port

[CZroe]

http://www.int03.co.uk/crema/hardware/game...gc-control.html


I'd like to make a device which draws its power from the Gamecube (All will be revealed when I'm finished!). Long ago as a pre-teen kid, I watched a few electronics videos and I know the difference betreen a volt and an amp, but that's about as far as I get. It's been years (I'm now 23), and I've done little more than a few PC and XBOX mods since.

First of all, how do I measure how much amperage the GCN controller outputs on the 5v line? How do I measure how many amps my 3.3v device will require? Will the total amperage output be less once I do the conversion to 3.3v?

Where can I find a schematic or guide for building something like a 5v-to-3.3v stepdown converter? The parts require nothing more than a trip to Radio Shack, right?

How can I tell if a power draw on the first controller port will affect the fourth? Are they the same "rail?" If I connect four of these devices, I'd want to make sure the GC could power them. Thanks!

[Scared0o0Rabbit]

you just need a pot to do your 5v to 3.3v, as for anything else in your post, I have no idea lol.


Edit: typo

[Guest]

I got information elsewhere saying I should use a voltage regulator, especially if I'm going to have four of my devices plugged in.

[hemphacker]

A voltage regulator would provide a much more consistant voltage than a pot. If the load changed, then the voltage would also, but if you're doing something with just LEDs or something, then a pot would probably work just find and add the ability to adjust the light levels (if you'd want to).

[HeartBurn Kid]

I think I know what he's doing (as I've considered the same thing myself), and if I'm right, then yes, you should use a voltage regulator, lest a sudden power spike fry your GBA.

[CZroe]

I think I know what he's doing (as I've considered the same thing myself), and if I'm right, then yes, you should use a voltage regulator, lest a sudden power spike fry your GBA.

Damn you! My patent is toast! J/K I was going to write a guide and put it up here, despite getting most of the technical stuff worked out by you guys

Yes, connecting more GBAs would almost certainly increase the load, but I was asking about seperate "rails" just in case someone happened to know that it operated this way instead.

I have no idea how to choose or wire a VRM, so perhaps I should just leave this up to you guys?

[phreak97]

EDIT: the LM317x is an adjustable voltage regulator, put a pot on it and use it as a reliable power source

do read the whole post, dont just skip to the wiring.

i believe this configuration of a voltage regulator LM317LZ or LM317T (both work the same, the T is just more heavy duty, and much larger) will bring anything from 5v up to 15v (using the LZ, the T may have a higher maximum) down to 3.5v (changing the value of the resister between pins 1 and 2 should change the output voltage, perhaps use a pot here if 3.5 is not good enough)
i have used this configuration in a playstation memory card reader/writer and it works.

with the regulator facing you i am naming the pins 1-3 from left to right.

connect a 470ohm resistor between pins 1 and 2.
connect an 820ohm resistor to pin 1.


pin 3 is 5v to 15v input. (connect to positive)
pin 2 is 3.5v output
the resistor on pin 1 is ground. (connect to negative)

--
this configuration was taken from http://members.aol.com/playsaver/ see this page for further details (or how to build a psx playsaver [memory card reader/writer])

[phreak97]

after looking in a gcn con with a multimeter today i found that the red wire in the controller cable is already 3.3v, its the yellow one that is 5v.. you can just use the 3.3v line to start with.. dont know if the amps are there to power a gba tho, i might try it out myself tomorrow.. my multimeter wont measure amps for some retarded reason, perhaps im just not doing it right.

[CZroe]

after looking in a gcn con with a multimeter today i found that the red wire in the controller cable is already 3.3v, its the yellow one that is 5v.. you can just use the 3.3v line to start with.. dont know if the amps are there to power a gba tho, i might try it out myself tomorrow.. my multimeter wont measure amps for some retarded reason, perhaps im just not doing it right.

But according to the pin out that is a 3.43v data line. I'd probably still need that connected to a standard GC-to-GBA link cable Or would it not be a problem to connect it to both as long as the amps are there?

[phreak97]

it didnt mind me running leds off it.. i know thats a little diff to a gba but still...