strophlex Posted April 23, 2009 Report Share Posted April 23, 2009 I am populating the CS of my MB6582 and it seems I have to mix red LEDs of different brands. I have 102 LEDs from Smash TV that I will use with 1K ohm resistors but i have to add at least 10 LEDs of a different brand that match with 330 ohm resistors for the same brightness. Does anybody know how I can find out what LEDs go with what resistors so that I can match a 1K/330 resistor combination on the base PCB with an appropriate LED setup on the CS? Quote Link to comment Share on other sites More sharing options...
latigid on Posted April 23, 2009 Report Share Posted April 23, 2009 So you need the board diagrams, right?http://www.mb6582.org/plans/MB-6582_CS_PCB_R2_Color.pdfhttp://www.mb6582.org/plans/MB-6582_Base_PCB_R2_Color.pdf Quote Link to comment Share on other sites More sharing options...
strophlex Posted April 23, 2009 Author Report Share Posted April 23, 2009 Yes and I found "Control Surface Wiring" at http://www.midibox.org/dokuwiki/wilba_mb_6582 (http://www.midibox.org/dokuwiki/lib/exe/fetch.php?id=wilba_mb_6582&cache=cache&media=mb-6582:mb-6582_cs_dout_wiring.pdf) and found out that it is not possible if I don't scatter the different leds all over... Maybe I do... Quote Link to comment Share on other sites More sharing options...
latigid on Posted April 23, 2009 Report Share Posted April 23, 2009 I guess that's what happens when you matrix the outs to save on board real estate and 595s... :( Quote Link to comment Share on other sites More sharing options...
latigid on Posted April 23, 2009 Report Share Posted April 23, 2009 Or, could you find out the spec of the LEDs from Smash and buy a few more? Quote Link to comment Share on other sites More sharing options...
strophlex Posted April 23, 2009 Author Report Share Posted April 23, 2009 Or, could you find out the spec of the LEDs from Smash and buy a few more?I could do that, but I want to complete this now ;) Quote Link to comment Share on other sites More sharing options...
Wilba Posted April 23, 2009 Report Share Posted April 23, 2009 The LEDs are (effectively) in one big 16x8 matrix, with 8 "columns" sinking current by the 3rd 74HC595 shift register (the one with the transistors), and 16 "rows" sourcing the current by the 1st and 2nd 74HC595 shift registers.8 "rows" are used by the 8x8 mod matrix LEDs, the other 8 "rows" are used by all the other LEDs.It's very easy to use LEDs in the mod matrix that are different to the other LEDs, you just use different resistors connected to the 1st and 2nd 74HC595... and in theory you could identify all LEDs in one or more "rows" and use a different resistor for those rows... but this solution isn't very good, as unfortunately those LEDs would be in different groups on the display, rather than being in one group (like LEDs in the SID 1/2/3/4 group, or the LFO waveform group).The best solution is just get some more red LEDs from SmashTV... if buying another pack of 100 is too much, I'll just send you some spares that I have here. You can solder the LEDs in two stages, it won't make a difference if you are soldering them while the panel and PCB are attached (as I recommend for perfect alignment). Quote Link to comment Share on other sites More sharing options...
strophlex Posted April 23, 2009 Author Report Share Posted April 23, 2009 I grabbed a led at work and if it fits I'll take some more from here, if not. I'll just leave some space in the mod matrix and buy another pack from smash tv. thanks for the offer wilba, you've just done more than enough allready. Quote Link to comment Share on other sites More sharing options...
Wilba Posted April 23, 2009 Report Share Posted April 23, 2009 hehehe I only offer because it's so easy to put a dozen LEDs in an envelope, $2 and you get exactly what you need in 4-10 working days :) Quote Link to comment Share on other sites More sharing options...
strophlex Posted April 23, 2009 Author Report Share Posted April 23, 2009 The leds from work looks much like the ones from smash tv, fingers crossed they match... Quote Link to comment Share on other sites More sharing options...
m00dawg Posted April 24, 2009 Report Share Posted April 24, 2009 The LEDs are (effectively) in one big 16x8 matrix, with 8 "columns" sinking current by the 3rd 74HC595 shift register (the one with the transistors), and 16 "rows" sourcing the current by the 1st and 2nd 74HC595 shift registers.8 "rows" are used by the 8x8 mod matrix LEDs, the other 8 "rows" are used by all the other LEDs.I'm guessing that means you don't recommend we mix LED colors in the LED matrix? I was wanting to do a VU meter type of thing (green, yellow, red) so that the VU meter mode would look cooler :) I'm not very familiar with how the matrix functions with the current sinking stuff, but I'm guessing I could use different resistors on one of the 74HC595's? Quote Link to comment Share on other sites More sharing options...
Wilba Posted April 24, 2009 Report Share Posted April 24, 2009 OT ALERT! :) Conveniently (by design) the 8x8 mod matrix LEDs are arranged so each horizontal row of LEDs is supplied by one pin of a 74HC595 so it's quite easy to put different LEDs in each row and make the brightness match. If you're going to do this, you might as well invest in some machine pin strips or chop up an IC socket, so you can swap resistors after everything is soldered and the control surface attached.However, different colour LEDs within the mod matrix might look a bit wrong in the other modes, but if you don't mind that then go for it, you should have no trouble matching brightness. Quote Link to comment Share on other sites More sharing options...
m00dawg Posted April 28, 2009 Report Share Posted April 28, 2009 Thanks Wilba! That's just what I thought it would be! Sorry to derail the train to off-topic land :) Quote Link to comment Share on other sites More sharing options...
strophlex Posted April 29, 2009 Author Report Share Posted April 29, 2009 Thanks Wilba! That's just what I thought it would be! Sorry to derail the train to off-topic land :)No worries, the leds I found at work was good enough to use, so I'm glad you could inherit the thread m00dawg :D Quote Link to comment Share on other sites More sharing options...
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