TheJudge: I’m not sure if you want to connect the button to the PCB, but you must do it (pad= PCB on the schematic). This will work if and only if the PCB is low active.
No, it’s just that easy.
Take this link to see my efforts in making led buttons.
The schematic
was drawn 11/2008 by me. Since that I’ve done a lot of led mods with this kind of wiring.
Take a look here for results:
[media=youtube]rjvEuWWuD_g"[/media]
[media=youtube]BaVEjkgLHGE"[/media]
[media=youtube]xbgSjlb7jSI"[/media]
Could post me a link to Andys work? I’m not sure that I see his work before…
Oh yeah, of course. Lol. I may give it a go at some point then.
EDIT -
Cheers, Ben. I’ll be sure to give it a go now. Just need to order some resistors and LEDs. Will report back in when I get it sorted.
Btw, just to clarify, did you drill a little hole in the buttons to fit the LEDs?
Yes, 5mm fits perfectly
I’m having a problem with a custom stick I bought a while ago that’s giving me a hard time to sort out, and I thought this thread might be some help.
The stick itself is functioning just fine, it’s just one of the LEDs that’s giving me some trouble. The buttons are wired to light up blue on press and orange when a specific joystick direction is pushed. The only thing that isn’t working is the orange light triggered on Left. Both colors of light come from a single LED in the buttons.
It’s really hard to do much troubleshooting, because the case of the stick is very tight on space, and all the wiring and breadboards are ziptied down on top of eachother. Since it’s a really specific part of the circuit, I was hoping someone might be able to narrow down which connections have might been breached.
I’ve spent a good couple hours tracing wires and staring at the insides of the case, and I can’t figure anything else out without making a mess of everything and possibly wrecking it. I’ll wait till tomorrow night for that, I think 
edit: [media=youtube]rcZj9xQx2h0[/media]
Hello to everyone,
I’ve been following this thread from the beginning and have already made my own LED modules with inverters …
I have two questions: - the first is about this first diagram where I changed SpeedsterHarry’s diagram to power the inverter from the PCB itself … can someone please confirm that this is correct?
http://img26.imageshack.us/img26/4864/ledmodwithinvertersfina.th.png
- the second question regards this new way of connecting LEDs without inverters that Andy wrote about a couple of pages back. Is this second diagram correct and this will really work the same as with the inverter module?
http://img26.imageshack.us/img26/6631/ledmodnoinvertersfinal.th.png
I am building a dual PCB stick (Cthulhu and MadCatz #4716 common ground gamepad) with an Imp board and I would like to add LEDs to all of this.
My diagram for everything together is this:
http://img9.imageshack.us/img9/1091/004dualpcbplusimpfinalp.th.png
And now I would rather make it more simple if this second way of connecting LEDs really works.
Thank you very much for your help and to everyone who has contributed to this thread.
That second way works, but for reasons that escape me, the hex inverter method is better. Toodles said something about it, but I forget.
The inverter-free method works iff the PCB is common-ground (since the led will shine when the signal is put to ground, which means the buttons was pressed).
I take it that the directions wires won’t go into the inverter, right ? The rest of the circuit seems OK.
If you check the LEDs on the last diagram you will see that I have put a LED to all buttons and all directions. Is there any problem with this? Do directions work any different than buttons?
So with this setup with the common ground Cthulhu, MadCatz and Imp … this simpler way will work? This way I could immensely simplify my LED module.
Ok, here it is. I made a new diagram with this simpler way of connecting LEDs.
http://img110.imageshack.us/img110/9717/005dualpcbplusimpfinalp.th.png
Can you confirm everything is correct or not and that it will really work? I understand the inverter method perfectly, but this one I just can’t get around to understanding why it works.
No, directions and buttons are treated alike, I wsn’t sure you would light-on the balltop as well. That will need 2 hex-inverters and a hellava wiring. I would not like to put all this into one stick but I’m not you
If you’re not confident about the simpler schematic, apply it only to 1 or 2 buttons and if you’re satisfied with the result, then roll on the rest of the wiring, otherwise revert to the inverter method.
If I were you, i’d use just the cthulhu with the leds and if all goes well, connect the madcatz pcb afterwards…
My MAME cabinet has half the panel using the inverter method and the other half using the alternative method. Both sides work very well, there’s no way to tell which is which when playing.
Yeah, you’re right about the extra wiring 
it’s 16 LED’s, which means 16 lines times 4 I think :)) I’m still thinking about how to organize everything, but no worries … as long as everything works
And I just thought of something, considering that both everything is common ground and powered all the time anyway, does that mean that both PCBs are sending button and direction signals all the time whichever you are using for the current console? If that’s true, then it would be enough to wire the LEDs to just one of the PCBs (i.e. the Cthulhu) and the other PCB would just be there wired only to the first PCB … and it should work with any PCB chosen, right?
And about the simpler method, I believe you just fine, if you say that it’s working, I just don’t know why exactly it works Or are there any other possible problems with it?
You’re right concerning the LEDs, they only need to be connected to one PCB ! I hadn’t noticed that 
Nobody seems to listen to Toodles or myself when we say that you can’t use the hex inverter for the joystick. If you want to light up the stick when the stick is moved you need to use a 4-input NAND logic chip (74HCT20).
The end result is like this…
http://i228.photobucket.com/albums/ee314/KaytrimsKustoms/Electronics/th_JoystickFlash.jpg
I’ll add this to the first post so it won’t happen again =P
yeah, that’s 16 wires less, just like that
Does this also apply to let’s say 4 separate LEDs for each direction or only for a single LED in the ball-top? I believe it should work with 4 separate LEDs.
===================
Ok, I removed the MadCatz lines to the LEDs and I also removed the connection from button to the Cthulhu as I am merging them in the terminal by the LEDs. Cthulhu should still work normally, right?
http://img33.imageshack.us/img33/9717/005dualpcbplusimpfinalp.th.png
I think it would be the same if I just connected the buttons and directions to the Cthulhu terminals and just connect the LEDs to the same spots. Am I mistaken? That way it would be really simple to add the LEDs at a later stage.
No, dont do that. You have the LED power lines coming from the Imp directly; it should come from the unlabelled VCC point the madcatz is connected to, or the VCC screw terminal on the Cthulhu.
I do think you’d be better off using the inverter to control the LEDs, but it may work just fine; I don’t know with the madcatz pcb. But, that’s your call.
In your position, the way I would wire things is to solder the wires in all of the unlabelled holes to go to the madcatz pad, and wire the Imp as normal. Then, have the LED setup all going into the Cthulhu screw terminals along with the wires going to the buttons and stick.
The NAND chip would be for a single LED in the stick. You should be fine using the hex inverter with one LED per switch.
I am with Toodles about using the inverters for the button mod. To me it adds a layer of separation. It just doesn’t feel right using a resistor inline with the button signal.
Michael
I’ve introduced this solution about a year ago or somewhat. But please take in mind. There exists several solutions about led mods. They all have advantages or disadvanatges.
My solution is ok for me, because I use this way in my own pcbs.
- no need for further parts and easier wiring
- no separation with gamepad pcb …
Inverter Mod:
- separation with pcb
- additional parts needed
however both way works very well.
@speedsterharry
sure? why it shouldn’t? for the led it doesn’t matter which GND it takes.
http://4.bp.blogspot.com/_YLXgzxS8cEc/SlWVEs-uYkI/AAAAAAAAAqA/ZD0ZQYvxIFQ/s320/JoystickLed.png
You can also take the “difficult” way here:
[media=youtube]M5qIRRzKrns"[/media]
Watch at 1:05
The led ball has a RGB led. On movement in different directions the led will light up in different colors. Don’t complain about the leds in the case. It was only fun 
Some PCBs use a matrix system to detect keypresses. The voltage between the two inputs “pins” may be inferior to the LED’s forward voltage, and in this case the LED won’t shine.
Also, some inputs can be high active and in this case, the whole schematic has to be changed (even the inverter one).
Of course, it’s best to understand how the electronics works here and adapt a few things if need be rather than blindingly following instructions given in the thread (this can be said of many things :wgrin:)
jep
wise words