Adding DB9 port for controller 1 to Power Joy

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famulator76
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Adding DB9 port for controller 1 to Power Joy

Post by famulator76 » Sun May 09, 2021 9:07 am

Hey all. Complete beginner to electronics here. I'd like to put the innards of a Power Joy inside a custom case. Controller 2 has an existing DB9 connector. I want to wire a DB9 connector for controller 1. I see five wires going to what was the Control Stick. I uploaded a picture here.

I see the pinout for famiclone controller at https://wiki.nesdev.com/w/index.php/Con ... ort_pinout. Is adding a DB9 port for controller 1 a matter of wiring those five wires to a male DB9 connector? I am assuming--perhaps incorrectly--that the five wires correspond to D0, OUT0, CLK, GND and 5V. How do I determine which wire corresponds to each function?

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Fisher
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Re: Adding DB9 port for controller 1 to Power Joy

Post by Fisher » Tue May 11, 2021 6:56 am

Could you please take a better picture focusing the small blob that seems to be connected to the d-pad and the 2nd controller connector?
That blob seems to be like the controller IC, maybe it's possible to add the port by picking the tracks that go to it.

famulator76
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Re: Adding DB9 port for controller 1 to Power Joy

Post by famulator76 » Tue May 11, 2021 2:06 pm

Fisher,

I uploaded several pictures at https://imgur.com/gallery/3PWw2UZ. I tried to zoom in on the blob you mentioned. I also took a picture of the bottom of the PCB which includes the cartridge slot.

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Fisher
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Re: Adding DB9 port for controller 1 to Power Joy

Post by Fisher » Tue May 11, 2021 3:24 pm

zcDRDzK1.jpeg
I think the input pins of the controller IC may be these 3 marked in red.
I really would like to hear the opinion of more experienced users, like Lidnariq and Krzysiobal.

lidnariq
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Re: Adding DB9 port for controller 1 to Power Joy

Post by lidnariq » Tue May 11, 2021 4:46 pm

Unfortunately, the wires famulator76 circled aren't the controller port: instead they're just ground and 4 button inputs for the thumb stick to do the same thing as the primary dpad.

We have a pinout for a UM6582 on our wiki, but that's a 16-pin part, and the footprint on your PCB only has 14 lands... but it looks like it might almost be the same with two extra pins at the top.

This implies that the chip-on-board there is a UM6582 - see also the turbo buttons - and you'll have to remove the chip-on-board in order to plug an external controller. After that, you can probably use the remaining UM6582 SOP footprint to attach the external controller.

famulator76
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Re: Adding DB9 port for controller 1 to Power Joy

Post by famulator76 » Wed May 12, 2021 5:39 am

lidnariq,

Thanks for weighing in. There's a lot in your response for a beginner to unpack. :D

I'm interpreting your reply to mean that under one of the blobs is a UM6582 and that it needs to be removed. I'm not clear on what to do after that. I recognize that I may have to do a lot of research given my skill level. I may need a nudge to get me started. How would I determine how to connect the 9 pin famiclone port?

lidnariq
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Re: Adding DB9 port for controller 1 to Power Joy

Post by lidnariq » Wed May 12, 2021 10:29 am

Easy thing first:

https://wiki.nesdev.com/w/index.php/UM6582_pinout

I suspect that pins 2-14 in the above link correspond to 13 of the pins on the empty square marked "UM6582" on your PCB. That's where you connect your famiclone controller. (What pins go where? I don't know, I've never personally seen a DE9 famiclone controller, so I don't know if there's one convention or multiple, or how to determine which you have. You said you already have one DE9 port for player 2; three of the pins should be shared between the two controller ports)

Hard thing second:

In order to use an external controller, you must disable the equivalent chip on your PCB. I suspect this is the black epoxy blob that Fisher circled next to. These epoxy blobs often come off with a bit of heat and force. A lighter and a screwdriver might be good enough.

Be careful: if you damage the other blob at all, you'll just have a piece of junk.

famulator76
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Re: Adding DB9 port for controller 1 to Power Joy

Post by famulator76 » Thu May 13, 2021 8:08 am

I understand. How would I wire a standard NES controller to the empty square marked "UM6582"?

lidnariq
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Re: Adding DB9 port for controller 1 to Power Joy

Post by lidnariq » Thu May 13, 2021 10:24 am

Connect VCC=+5V, GND, D0, CLK, and STROBE=OUT.

https://wiki.nesdev.com/w/index.php/Con ... ort_pinout

I have read people finding multiple different 9-pin famiclone pinouts, so do NOT assume that the one on the above page is correct for you!

krzysiobal
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Re: Adding DB9 port for controller 1 to Power Joy

Post by krzysiobal » Fri May 14, 2021 9:53 am

I have meet similar handheld famiclone and even analyzed it at that time.
* First blob is NES-on-Chip
* Second blob is PRG ROM, CHR ROM and mapper
* Third blob is joypad controller (which as lidnariq find out is UM6582)

What I would recommend is not to remove the controller blob but instead, cut its data-out track, add two diodes to make OR gate to connect external controller. This way you still can use the built-in joypad.

The DB9 plug has two GNDs and two +5Vs so you can modify it and route $4016.D0 and $4016.CLK to it

Code: Select all

                               +5V
                                |
                               2.2k
                                |
D of UM6852----------------|<---+--------D of Nes-on-chop blob
                                |
D of external joypad #1----|<---+
Attachments
20200324_214116.jpg
sch.png
bottom.jpg
top.jpg

famulator76
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Re: Adding DB9 port for controller 1 to Power Joy

Post by famulator76 » Fri May 14, 2021 11:12 am

krzysiobal, thanks for the tips and the schematic. BTW, I received your flash cart few weeks back. Great product.

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