did a NES Pad Hack... but need help (with PICs :) )

[scorp.ius]

Hi!

Its not really an Arcade control. i wanted to use an old NES Pad on my PC... so i soldered a NES Pad to an USB Pad.

BUT: when i press "UP" on the NES Pad i get a "UP + B"
when i press "A" - i get a "A + LEFT"

just examples i dont know it for sure now, but pressing the digipad i get a direction an a button - the same with the buttons vice versa

the start and select buttons are working correct

the strange thing is: i startet with A and B only, and with only 3 wires soldered (A + B + one GND) it works for this two buttons correct.

question: what are those resistors(?) after the buttons and digicross for?

the first picture is the NES Pad - the second the USB Pad

[NickG]

Those diodes are there to protect crosstalk between the inputs.  They are supposed to ensure that a keypress only has one path to ground.  You'll notice on the USB pad that the direction controls are grounded via pin 19, but the buttons are grounded via pin 20; so you need to separate the paths. 

[scorp.ius]

thanks for the fast reply  

unfortunately i dont exactly know what you want me to do 

could you please precise your answear?

EDIT: i think i have only ONE ground in the NES Pad, right? (the black wire that is connected the "start" buttons ground on the USB pad) so how could i seperate this one wire?

[steveh]

why would you do such a thing? 

http://www.retrousb.com/usb.html

you can get adapters, and kits to mod your controller right to usb.  much better way of doing it.

I guess your way is more challenging.   I can vouch for this company as i have purchased both kits fro my genesis controllers.

[somunny]

why would you do such a thing? 

The 'B' in BYOAC stands for 'build'.  Granted, the products at retrousb are nice but some folks want to do it themselves.

[NickG]

Do you have a multimeter?


You will probably need to cut the trace on the NES pad.  You may have to separate only the DPAD section, so start there.  You may find later on that you need to separate the button section from the [start and select] as well.  If this happens you will make at least two cuts in the common trace on the NES pad. 

The following is speculation:
  Cut the common trace to the left of the notch near the Printed number 9 on the NES pad to isolate the section from the other inputs.  Then solder the black wire that is currently on the USB "start" button to the diode-side of  SW11, SW12, SW13, or SW14.  (you may find that it is easier to solder directly to one of the diodes' solder points, instead of trying to glob solder on the contact pads.)

Then test the direction pad inputs to be sure that they work.

If they do:

Next, run two new wires from the NES pad to the USB pad in the same manner:
keep all three sections separate and it might work out.

to be clearer, one of these new wires should connect the start-select section commons of both controllers, the second wire should connect from the NES pad A-B button common to one of diode-side of SW1,SW2,SW3 or SW4  (or, once again, one of the diode inputs, instead)

Good luck, you can do it!   

[scorp.ius]

hi... i have tried this. the direction pads are working this way... but the buttons are diections now - without A or B

now button B is up and Button A is left 

i think the usb Pad i have is not the best one for such a project.

some people use USB Pads for there Cabs right? there must be some easier pads perhaps?

@retrousb
those adapter are not cheap (ie expensive) and i thought it would be a nice try - Hey! This is a DIY Forum right?