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geekhack Projects => Making Stuff Together! => Topic started by: Ari Gold on Sun, 18 January 2015, 01:39:58

Title: Pcb with controller for coolermaster switch tester
Post by: Ari Gold on Sun, 18 January 2015, 01:39:58

Hey,

Another new member here. Been browsing for a while though!

I recently joined the MD drop for the CM switch tester. And that got me thinking, it seems such a waste of money. I could have gotten plenty of switches for the same amount of money.

So why not make use of it, and handwire a teensy.
But that would total at about $40 for just 6 keys.

So using the teensy just seems way more expensive then needed.

So why not design a small pcb with a basic controller, that still allows nkro, 1 or 2 function layers (resulting in 10 and 12 functioning keys each)

How would I design such a thing, and if it ever gets to being produced, would it be worthwile and not overly expensive?

Regards,
Thomas

Title: Re: Pcb with controller for coolermaster switch tester
Post by: dorkvader on Mon, 19 January 2015, 21:33:04

You mean like this:
https://geekhack.org/index.php?topic=67338.0

Title: Re: Pcb with controller for coolermaster switch tester
Post by: SpAmRaY on Mon, 19 January 2015, 21:37:17

Quote from: dorkvader on Mon, 19 January 2015, 21:33:04

You mean like this:
https://geekhack.org/index.php?topic=67338.0

He doesn't want to have to use a teensy.

Title: Re: Pcb with controller for coolermaster switch tester
Post by: dorkvader on Mon, 19 January 2015, 21:42:07

Quote from: SpAmRaY on Mon, 19 January 2015, 21:37:17

Quote from: dorkvader on Mon, 19 January 2015, 21:33:04

You mean like this:
https://geekhack.org/index.php?topic=67338.0

He doesn't want to have to use a teensy.

I mentioned in the topic I linked that you could build something like that with an arduino pro micro for cost savings.

Title: Re: Pcb with controller for coolermaster switch tester
Post by: jdcarpe on Mon, 19 January 2015, 21:42:27

The Techkeys business card uses an ATmega16U2, right? Those are pretty cheap, and would be useful in such a project.

Title: Re: Pcb with controller for coolermaster switch tester
Post by: Grendel on Tue, 20 January 2015, 13:58:00

Not necessarily -- you still need some external components like an oscillator, resistors, USB connector. IMHO the cheapest (and a lor more easy) way is to use a Pro Micro clone (seen these for ~$6 on eBay.)

Teensy's have a very good reliability record tho, I'll most likely stick to it for more SixShooter boards.

Edit: Also, the U2 chips have only two timers, driving 4 LED's via PWM is already pushing it. The U4 chips allow you to drive 6 LED's w/o problems.

Edit2: Well, except the Pro Micro -- looks like only 5 of the 6 PWM channels are available on the pads :(