NES controller decoder

knohbody · Post by **knohbody** » Sun Oct 18, 2009 8:27 am

Ok guys, I'm trying to build a slightly modified version of this :

NES adapter

I'm just trying to convert the button presses from the NES controller into a basic parallel output (i.e. what the neogeo uses) so I can interface it with a UPCB.

Toodles' UPCB

I've built the circuit, minus the part that converts the digital signal to analog, which includes d1-4; R5, 6, and 7; and Q1 and 2.

When testing the circuit, the output lines go low only when A is pressed. No other button does anything, and button A triggers all outputs. Anyone have any clue what I did wrong?

Thanks.

Post by **tepples** » Sun Oct 18, 2009 6:15 pm

Button A means that either the controller isn't seeing clock signals, or your interface is not re-latching the controller's output after each clock signal.

knohbody · Post by **knohbody** » Sun Oct 18, 2009 6:42 pm

Tepples,

Thanks for the input, I'll check the clock and latch lines, and especially the 555 timer I have in there.

Super-Hampster · Post by **Super-Hampster** » Thu Feb 10, 2011 6:10 pm

Sorry to resurrect such an old thread but I was interested in this as well but it seems the link is dead. Would anyone have a copy of what was once on the other end of that link?

chykn · Post by **chykn** » Fri Feb 11, 2011 6:06 am

Do you use either AVR or PIC microcontrollers? I don't have the source or schematic for the above links, but I have written some AVR and PIC firmwares to accept NES controller input then output to either parallel or RS232.

Super-Hampster · Post by **Super-Hampster** » Fri Feb 11, 2011 9:23 am

I was hoping to do it all with a '595 and a clock signal generated maybe by a 555 or something like that.

Post by **tepples** » Fri Feb 11, 2011 9:52 am

Does the Neo Geo controller interface provide any sort of clock or strobe signal?

I noticed C and D buttons on the pinout. You might want to make your circuit read 10 buttons so that it can use the extra buttons of a Super NES controller (in the order B Y Select Start Up Down Left Right A X).
In any case, you want to toggle strobe once and then toggle the clock at roughly 250 kHz.

kyuusaku · Post by **kyuusaku** » Fri Feb 11, 2011 1:11 pm

Super-Hampster wrote:I was hoping to do it all with a '595 and a clock signal generated maybe by a 555 or something like that.

I described a circuit like that here:
http://nfggames.com/forum2/index.php?to ... 6#msg26296

I typoed, 594 = 595. To make an oscillator use something like this: http://electroschematics.com/wp-content ... lasher.jpg and to choose a frequency use this: http://www.muzique.com/schem/filter.htm

tepples wrote:Does the Neo Geo controller interface provide any sort of clock or strobe signal

Yes, but it is unused on any Neo Geo controller (they are completely passive).