MiSTer FPGA Forum

I'm installing my MiSTer into a mini itx case... I'm using 12mm halo led momentary buttons for the 3 user buttons.
The mister io add-on board has a connector for external buttons and LED's and I've ordered a JST/XH connector kit to wire up cables for these buttons...

My concern is ive read these headers on the io board only output around 3v for the LED's.
Is this true?

Can I get more output if I piggyback off the actual LED's on the io board?

I'm concerned because the momentary switches are rated for 12v but read they work fine with 5v and are just a little dim which is what I want but I'm worried 3v won't be enough to even see them.

Would I be better off / or is it possible to splice in 5v from the cases power source and daisy chain that 5v to the button LEDs and then get each led ground signal from the io board connection header?

Thanks!

I think the trouble is the the IO board already provides +5v, it is the ground that generates the 3v differential by only dropping to 1.7v and therefore I don't think splicing from a different 5v source will help. Obviously the LEDs won't mind a lower voltage than they are rated for but will indeed be dimmer. Really you should get halo LEDs that are rated for 5v rather than 12v, in which case 3v will provide a good level of brightness (at 5v I find them distractingly bright). Those LEDs have an internal resistor based on the volatage rating so I don't think there will be an easy way to get the 12v ones working.

Yeah, sadly I couldn't find anything 5v stateside and didn't want to wait months on a China epacket.
Looks like I'll have to do some more searching.
It sucks because these buttons were $40


Edit.... did some more looking around, found some 5v in the US but are $12 ea.
I just ordered them from China for $1.50 ea. I guess I'll wire up the 12v ones I have and swap in the 5v ones next year when they show up lol

Do you have the digital or analog io board.

I think that the digital led header levels are 3.3v off and ground on, whereas as mentioned above the analog is 5v off and 1.7 v on? But my memory might be failing me!

I have the digital board and used an hct hex inverter to invert 3.3 and gnd to gnd and 5v which luckily is what my case's led circuit board needed.

I have the analog

The 12v buttons worked out great.

hey! nice setup...
Im looking at using the same type buttons...do you have a picture and/or info on the wiring for the led and power?
Did you end up using the JST/XH connector kit and split/cut the ends?
Im looking to have my buttons mounted into a joystick panel im building so will have long wire lengths...so getting the JST/XH connector kit might not be worth it....but im not sure on the correct gnd/pos etc..
thanks!

BritX wrote: ↑Fri Jan 28, 2022 6:02 pm hey! nice setup...
Im looking at using the same type buttons...do you have a picture and/or info on the wiring for the led and power?
Did you end up using the JST/XH connector kit and split/cut the ends?
Im looking to have my buttons mounted into a joystick panel im building so will have long wire lengths...so getting the JST/XH connector kit might not be worth it....but im not sure on the correct gnd/pos etc..
thanks!

Sorry Im 10 months late...lol.... never seen the notification, but will post this in case others in the future need it. Wiring info in the vid
https://www.youtube.com/watch?v=DP_01EUOKJs&t=2211s

I never saw this before now. Very nice build!