yet another volcano button question (& Keywiz)

[mmmPeanutButter]

Ok, I searched.  I found out a lot.

Get Atari cone buttons on ebay.  Check.

Connect in parallel.  Check.

Use a 330 ohm resistor for each.  Check.

But I still have a couple questions (I am such an idiot when it comes to anything electrical, so please forgive me).   

Ok, my keywiz has a 5v connection.  I would like to put two wires into this connection.  Each wire will be connected to its own resistor.  Then one wire will go to one LED and the other wire to the other LED.

First, is this right?  Somebody metioned something about finding how much current I can draw from the 5v on the keywiz so I don't damage it (RandyT??).

Now, I need a ground for the other side of the LED (right?).  Can this be connected to the same ground that I used for all of my buttons??

I have a feeling I might be right, but I don't want to risk messing up my buttons or the keywiz.  Any help would be great.


EDIT: I guess I'm an idiot.  Reading the instructions for the keywiz, it says (in bold) "WARNING! Before wiring switches to the KeyWiz, locate and identify the +5v connection.  Shorting this terminal to ground will cause severe damage to the KeyWiz and your computer! BE CAREFUL!

So now I'm even more confused.   



Here is a link to my project if you want to see it.

[HoopstarsGarage]

I assume that both the Keywiz and the Ipac's use the same kind of switching - that is the Caps Lock, Scroll Lock and Num Lock pins are grounded when "on"..

In otherwords, you connect your 330ohm resistor to the +5v line, then to your LED, then from the LED to the interface.  The interface will "connect" (internally) the LED to ground when it needs to switch on..

check out Andy's Site for more info - but like Isaid, I am only ASSUMING that this is how Keywiz do it..

http://www.ultimarc.com/ipac2.html


Hoops

[mmmPeanutButter]

I hope this isn't too annoying seeing how this post is pretty dead...

But I gave RandyT a little nudge to take a look at this post and he cleared everything up via e-mail.  I just thought I would post what the outcome just in case anybody searches for this in the future.

mmmPeanutButter says:

Randy,
I posted the above question a little while ago and I sent you a PM to take a look at it.  I don't always trust that people check their PM's so I thought I would send you an e-mail.  If you could take a look at my question and post a response that would be great.  Thanks so much.

RandyT says:

If alll you want to do is make the LED's stay lit inside the buttons,
everything you said sounds appropriate.    Split off the 5v to 2 resistors
of the proper value (for you to decide) then connect wires from the
resistors to each of the respective anodes (+) of the LEDs.  Then hook the
cathode (-) to your ground line.  There should be plenty of current to run a
couple of LEDs in this manner.

mmmPeanutButter says:

Great.  thanks for the reply.
So it can be the same ground I use for the buttons?  I asume that a ground is a ground is a ground.  Thanks again.

(yes, and that's all I want to do is light up the buttons when the computer is on)

RandyT says:

Yep!  Ground is ground, so no problems.

Simon says:

Touch your knees.



So it looks like it's all resolved.  Thanks for the help randy.

[pointdablame]

* pointdablame touches his knees.

Good info, I'm sure someone can find it useful.

[SirPoonga]

I assume that both the Keywiz and the Ipac's use the same kind of switching - that is the Caps Lock, Scroll Lock and Num Lock pins are grounded when "on"..

In otherwords, you connect your 330ohm resistor to the +5v line, then to your LED, then from the LED to the interface.  The interface will "connect" (internally) the LED to ground when it needs to switch on..

check out Andy's Site for more info - but like Isaid, I am only ASSUMING that this is how Keywiz do it..

http://www.ultimarc.com/ipac2.html


Hoops

FYI, the keywiz does not support keyboard LEDs.  So no blinking lights for credits with atari games

[jcroach]

Great questions.

[Tiger-Heli]

The ultimarc site has great info on it for their products. 

I found this on the site for the I-Pac.

LEDs: The three LEDs use the following inputs, which become bdirectional:
Player 1 Button 7
Player 2 button 7
Player 1 button 8
These inputs can still be used for buttons even if LEDs are connected but note that when the buttons are pressed the LEDs will light. You can wire your own LEDs to these connections.

I have the I-Pac VE which doesn't have an LED header, so I'm going to conenct up to the inputs as quoted above. 

One question, Andy Warne from Ultimarc e-mail me a while back and recommended 220 ohm resisters, but HoopstarsGarage recommended 330 ohm resisters.  I'm a little confused, but granted I know nothing about electricity! Anyone able to shed some "light" on the subject?  Sorry, bad pun.

The Ultimare site has good info, but nothing like you can get from this board.  You don't want to use Buttons 7 and 8 with the VE, btw, from my upcoming encoder page revision:

I-PAC LED Considerations

On all Ultimarc encoders, LED

[RandyT]

Your questions about this should probably be posed directly to Andy if you want info specific to the IPAC.

But the difference may be accounted for by the fact that the LED output on a bi-directional pin would be modulated (meaning that the signal to the LED is still 5v, but it's cycling on and off very rapidly) so it may be possible to use a lower value resistor without harm.  LED's are usually capable of much higher output when modulated.

The only caveat is that when the button on a bi-directional port is held down, the LED is no longer being modulated and a lower value resistor becomes a "bad thing".  So if you are using them bi-directionally, make sure you have the right resistor in there based strictly on the Ohm's law based equation:

Resistance=(Source Voltage - LED Operating Voltage) / LED Forward Current

But as always, don't attach an LED (or any electronic component) where the current requirements exceed what is available at the source you want to draw it from.  Otherwise, the result will almost always be damage to the source.

RandyT

[Tiger-Heli]

The only caveat is that when the button on a bi-directional port is held down, the LED is no longer being modulated and a lower value resistor becomes a "bad thing".  So if you are using them bi-directionally, make sure you have the right resistor in there based strictly on the Ohm's law based equation:


Resistance=(Source Voltage - LED Operating Voltage) / LED Forward Current

Also, just to clarify - I believe I read earlier that the Pin Header and the screw terminals are physically connected, so regardless of how you wire them up, you are using them bi-directionally if you have any switch connected on the corresponding input.

[mmmPeanutButter]

RandyT, I sometimes wonder if the guy in the KeyWiz logo is modeled after you.   

That would be pretty cool. 

How do women like the pointy hat?   

[Tiger-Heli]

RandyT, I sometimes wonder if the guy in the KeyWiz logo is modeled after you.   
That would be pretty cool. 
How do women like the pointy hat?   

Looks more Hulk Hogan-ish to me.  But Randy could be Hogan's twin for all I know.

[SirPoonga]

NOTE: The LED will flash when these buttons are pressed, whether the LED's are wired to the Button Terminals or to the LED header pins.  If this bothers you, there are two ways to work around this: a) design your panels so that these inputs are not required on panels that use the LED