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LED discussion
Posted: 24 Nov 2012, 18:54
by 7bit
I know there was a thread on that other website, but I didn't find one here.
Is it possible to use a matrix for the diodes, or does every diode need its dedicated connection to the controller?
I found this somewhere and wonder if it works with a teensy or teensy++ controller:

Posted: 24 Nov 2012, 19:21
by Soarer
Posted: 24 Nov 2012, 19:46
by 7bit
I know, but I don't want to read through all those pages.

Posted: 24 Nov 2012, 20:07
by Soarer
Then start at the end, numb-nuts!
If you only want on/off or single overall brightness control, then maybe. It still requires external components to provide enough current.
If you want individual brightness, or just an easy life, then go for the chip that __red__ found.
If you want a more in-depth answer... RTFT!!
Posted: 24 Nov 2012, 20:17
by 7bit
Thanks!
But at the moment I only need to know how the LEDs should be 'wired up'. Alternatively, I just can leave holes and you LED-fetishists can wire them with real wires instead of just soldering them into a pre-existing keyboard matrix.
Posted: 24 Nov 2012, 20:40
by Soarer
Might be best. There's no telling what levels of wrongness will be reached if you rely on some lazy-assed old bugger like me to give you an answer!
Besides, you haven't even said what you'd like to achieve with said LEDs... simple glow, or fancypants stuff?
Posted: 24 Nov 2012, 20:56
by 7bit
I think it should be doable with that matrix if it is just on/off all in one color a time. I don't think there is enough space on the PCB for anything more fancy. One option would be to have a separate LED-PCB.
I just want to save time and concentrate on one thing and don't want to get into more detail than necessary to know how to place the traces for the LEDs.

Posted: 24 Nov 2012, 21:27
by Soarer
Well yeah, I was assuming just one colour, since multicolour would be 3x the pain.
If you don't want to be able to draw patterns with them, then you don't even need a matrix.
You will at least need to go into enough detail to understand some of the tradeoffs in different methods... and most of them were discussed in that thread.
edit: for the simplest option, dig out the Deck schematics.
Posted: 24 Nov 2012, 21:55
by tlt
Maybe doing it with Charlieplexing like the LOL shield
http://jimmieprodgers.com/2009/12/my-de ... t-process/.
Posted: 24 Nov 2012, 22:06
by tlt
Sorry, Im tired I guess that matrix is the same thing.
Posted: 24 Nov 2012, 22:11
by 7bit
tlt wrote:Sorry, Im tired I guess that matrix is the same thing.
Yes, seems so. Thank you for that link. I think it will be the way I'll do it. If someone needs it more fancy it is still possible to wire them up manually.
Next step for me: writing a script to generate the scheme file.
Posted: 24 Nov 2012, 22:24
by Soarer
It was painful enough watching you start to design PCBs, but this is really making me want to scream STOP! now
Sorry to be so blunt.
If it was just you doing it for yourself I'd be all for it.
But for a group buy? No. Really. This is getting ridiculous.
Posted: 24 Nov 2012, 23:26
by tlt
I think its great that 7bit is doing this, it's the kind of thing I like about this community.
Posted: 24 Nov 2012, 23:35
by 7bit
Soarer wrote:It was painful enough watching you start to design PCBs, but this is really making me want to scream STOP! now
Sorry to be so blunt.
If it was just you doing it for yourself I'd be all for it.
But for a group buy? No. Really. This is getting ridiculous.
Don't see the point. I conquered the keyboard itself, now I can add some fluff to sell more.

Posted: 24 Nov 2012, 23:59
by Soarer
tlt wrote:I think its great that 7bit is doing this, it's the kind of thing I like about this community.
I hear the Top Gear presenters are starting a group buy on convertible MPVs... want one?
At least they tried a prototype!

Posted: 25 Nov 2012, 00:53
by tlt
Yeah! why don't they have those at my local car dealer?
