Wiring Dummy Arcade buttons

[rickc]

Hello. I am designing a kids game where a steering wheel is turned which then causes a rocket to move up a threaded rod. On the front panel of the game I would like to have a row of led arcade buttons. These buttons serve no function other than lighting up for a "control panel" look. What is the easiest way to wire and power these buttons seeing as how they serve no purpose other than aesthetics? Thank you!

[Nephasth]

Use dummy wire.

Just wire the LEDs to the appropriate power. No need to wire the switches.

[rickc]

Thanks. I am completely new to all of this. I saw in a few places that a 12 v HDD power supply and molex connector are used. Is there a post or site which shows this process in detail?

[JDFan]

Thanks. I am completely new to all of this. I saw in a few places that a 12 v HDD power supply and molex connector are used. Is there a post or site which shows this process in detail?

DEpends on the application -- Are they 12V or 5V LEDs ?? and how much amperage do they need (for each one and how many are being used)

What you will need is a power source that provides the proper voltage and can supply enough amperage to run all of the buttons - the reason many use the computer power supply is because it is already available if using a computer for the arcade - in your case it would be overkill and you'd be better of with just a normal AC adapter that has the proper voltage (can probably pick one up at goodwill for about $1) something like shown below just need to know what voltage is needed and what amperage overall to be sure that the one you get can handle all of the buttons.

[rickc]

Thanks! I do have a couple of laptop power adapters that I'm not using. Take a look at the attached pictures. Am I on the right track if I want to illuminate 9, 12v buttons? I know this is not an "arcade" question per se, so I appreciate your willingness to answer.

[JDFan]

That should work fine --- according to this advert their buttons require

LED voltage: DC 12V, 20mA.

SO if yours are similar you will need a 12V supply that can handle 180mA (or 0.18Amps) so pretty much any 12v adapter should be fine for that small amount (even a 250mA adapter which is about the smallest I've seen for sale.)

All you need to do is figure out which wires are the ground and +12V coming out of the adapter and connect your red and black wires from the wiring harness to those (normally black to the ground and red to the +12V) and then connect one red and one black wire to each of the led connections on each button. FOr example in this pic the ground and +12V on the side of the button - (not the connections on the microswitch as those are not being used in your setup other than to provide some click feedback when pressed)

[lamprey]

Do you want the lights to just be on or do you want them to blink or change in any way?

If you want them to change, then you'd probably want to look at an LED-Wiz or a PacLED64 in combination with something like LED Blinky to drive them.

[SavannahLion]

For future reference. The wallwart JDFan links to looks similar to the 5v-ish wallwarts used on cell phones. Best to avoid them unless you know your stuff. Hint: You know your stuff when you don't have to ask. No, I usually have to ask.

 Many of these 5v or so wallwarts have A) have piss poor power regulation, showing something like 10v on a voltmeter then slumping by as much as half when you approach their rated amperage. These suck ass because as you hit their rating I've rarely seen it put out 5v. Or B) the power rail is incredibly dirty. This is common with USB chargers. USB spec has loose requirements so a lot of companies cut corners. Some so much so that you'll get as much as the barest regulated 12v or more from one depending on the resistance of the wire to cut the voltage. Pure crap.... worse... you'll find warts that both problems. Throw any of those you find away, don't even use them for spare parts.

9v and 12v have crap wallwarts but I find more good than bad ones. The 5v power market is saturated with pure crap. I quit using the to power even my 3.3v projects.

Do you want the lights to just be on or do you want them to blink or change in any way?

If you want them to change, then you'd probably want to look at an LED-Wiz or a PacLED64 in combination with something like LED Blinky to drive them.

Did the OP say he was using a PC? I thought this was a standalone necessitating the need for a microcontroller like AVR, PIC or ARM.

[rickc]

Awesome information. There is no PC involved, just a standalone unit with arcade buttons lit up. That was the original plan but since then, I've been on aliexpress.com and I've found some other things to add. At this point I'm operating under the assumption that the 12 volt adapter that I posted above, with the molex end, will power a daisy chain of LED lights. Now I'm thinking about adding three 12v toggle switches for realism sake :-) is there any reason why that wouldn't work? Look at the original picture that I posted, and imagine three toggle switches at the right side of each row of arcade buttons.

[rickc]

Awesome information. There is no PC involved, just a standalone unit with arcade buttons lit up. That was the original plan but since then, I've been on aliexpress.com and I've found some other things to add. At this point I'm operating under the assumption that the 12 volt adapter that I posted above, with the molex end, will power a daisy chain of LED lights. Now I'm thinking about adding three 12v toggle switches for realism sake :-) is there any reason why that wouldn't work? Look at the original picture that I posted, and imagine three toggle switches at the right side of each row of arcade buttons.

[SavannahLion]

It should.

At that point I would seriously consider using a Microcontroller to get some simple lighting and simple "action" from your LED lights. If you're comfy with software, consider an ARM board. The Stellaris Launchpad goes for about $12 or so and the IDE has some very easy to digest examples and tutorials. It is a 3.3v board so you do have to build around that.

If you think C is just the third letter of the alphabet, shoot for an AVR8 such as the Mattairtech MT-DB-U4 or any other 32U4 based board (do not use the Teensy series). If you pick a KADE compatible board that is also Arduino compatible, you can use the Arduino IDE for development or use KADE if you ultimately decide to us a PC. 32U4 is a 5v (though it can be a 3.3v) part so i5's easier to build.

Both the Launchpad and MT-DB-U4 can be powered via USB based supplies. So care should be taken when running a bunch of LEDs. I've consistently used the 32U4 against 16 LEDs and a small circuit with ZERO problems.

[rickc]

I am an absolute beginner with a desire and ability to learn quickly. I've been watching Arduino tutorials on YouTube and I am intrigued by the possibilities. Now, a newb question.. how do you power a string of 12v items with a 5v board?

[WakiMiko]

Even without a microcontroller, you could make a button only light up when its pressed. Or make it light up another button. Or require two buttons to pressed for a third one to light up. All through clever wiring.

But a MC would probably be the easier and more flexible solution.

[rickc]

That's true! I've been planning on using the buttons simply for their LED illumination but, like you noted, if I actually use the button functionality I have quite a few possibilities.

[SavannahLion]

I am an absolute beginner with a desire and ability to learn quickly. I've been watching Arduino tutorials on YouTube and I am intrigued by the possibilities. Now, a newb question.. how do you power a string of 12v items with a 5v board?

Depends on what it is you're trying to drive. Switches aren't actually 12v per se. That's just their rating. A 120v AC switch is constructed a little differently than a 12v DC rated switch. Since this isn't going into medical equipment and you're running under 12v anyways, either will work.

LEDs are a little different but those 12v LEDs are really nothing more than a resistor and 1 or more LEDs. Generally packaged for the automotive market for kids with rice burners and too much money. Most resistors are something like 1.2v items (ballpark), so with the right resistor value you can run 4 or so LEDs in a series for 5v. What I'm trying to say is the same LED can be used for 3.3v, 5v, or 12v merely by changing resistor value and LED count when in series.

[rickc]

So, I ordered an Arduino UNO but upon doing some research (which probably should have been done before ordering), I am arriving at the conclusion that controlling 9, 12v LED buttons is too much for the Arduino to handle. Is this correct?

This thread has opened up a new world to me.. the Arduino has piqued my interest

[SavannahLion]

The Uno is based on the Atmega328P. It's a good MCU with lots of support but it wouldn't be my first choice as a beginner board. I always felt the Atemga32U4 to be better suited. But that is neither here or there. I would go to the Atmel site and download the datasheets for the Atmega328P (the P is important) to at least get a general idea of what it is and how it works. The Arduino guys tend to gloss over a lot of details.

Don't think of the switches as being 12v DC, think of them as being a MAXIMUM of 12v DC. That means the AVR can easily handle them. Tie ground to ground and the switch NO side to your AVR. Make no connection to 12v anywhere.  Since you're new, you might want to wire a small resistor in there to prevent burn out if you misconfigure the AVR pins. Otherwise use the AVR pullup to default to an on state then watch for a 0 when the switch is closed. Debounce is required but the Arduino library should take care of that. I don't use the Arduino library so I don't know the specifics of it.

LEDs are a little different. They're generally something like 1.2v or less and a resistor allows them to be run off of 12v or whatever.
If you MUST use 12v LED, then you'll need to use a BJT NPN like the 2n2222. FET will work but I don't know the 2n2222 equivalent off the top of my head. The UNO can sink or drive some combinations of LEDs at 5v without a transistor but care must be taken not to burn it out with excess current by turning on all the LEDs at once. A small handfull is fine. 30 is not.

[rickc]

Thank you. As one new to this, it will take some time to digest all of that information. I have been playing with an Arduino simulator at 123d.circuits. . Is this a good simulator to use or is there a better?