bugfight
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Posts posted by bugfight
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Eitherway, is not the max source current +/25mA?
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i calculated 18.75mA based on max power for the chip (750mW according to ti)
this may not be a good way to calculate the current limit.
wilba pointed out that max current at the power pins is listed at 70mA. though i don't think this translates exactly to the current at the outputs when they are pulsing, it still suggests a lower limit.
SmashTV did some tests that seemed to support the ~18mA calc
(even running it at 2A for 5 secs before letting out the magic smoke)
i'm sure some folks here are using more than that with high current leds, these ratings usually have a little headroom...
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let's say all the red leds are ON in row 1. Wouldn't that mean that 4 leds are being driven by a single SR pin out? (but each of the 4 pins on the Cathode SR is sinking a current)
yes but only one at a time, the code steps through sinking row 1, then row 2, etc...
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The max current a single pin on a Cathode SR would sink is when a whole column is lit up and all three colours are being used. If rgb this would be 24x Id (led current). ULN2003A can sink tons of current so this is not an issue.
yes
As for efficient RGB leds, I just bought custom made, superbright RGB leds from china. They have flat tops and are diffused. Unfortunately I wish there was a little more plastic on the tops of them to help diffuse the colors better but I am fixing that putting a short plastic tube on each one and then putting a semi-translucent plastic where the holes will be on my front panel.
The red draws the most current at 0.6 mA with the brightness I want (and I get a smooth 180 degree viewing angle once it is appropriately diffused). The other colours draw 10x less!!
cool, you have link?
If you look at the code I posted above, ...
sorry, i'm not going to look thru all that code looking for changes.
if you have a specific issue, i will be happy to help if i can...
HOWEVER, I need a 8x16 matrix of leds so I need this code to drive two 4x16 matrices, not two 4x8 matrices
OR should I just have a second core do this? I have no issue with chaining multiple cores but I have a feeling I may not need to.
i believe duping the code to get 8x16 is no problem for one core, except that you will have no douts for other uses...
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wow, that's some efficient leds!
ref http://www.ucapps.de/mbhp/button_duoled_matrix.pdf
the supply side of the blm circuit (DEFAULT_SRM_DOUT_L1, DEFAULT_SRM_DOUT_L2) is no problem since each pin only supplies 1 led at a time.
DEFAULT_SRM_DOUT_CATHODES1 on the other hand sinks current for the whole row at once
(i mistakenly said 16 leds before, which is correct for duo leds but for rgb it will be 24)
to simply add a third led color, you would add DEFAULT_SRM_DOUT_L3...
(for the left side that is, the same applies to the right side)
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you shouldn't have to change this code at all since the column index is the same for all 3 colors.
also note that current sinking transistors will be an absolute requirement to handle the current from 16 lit rgb leds...
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the &= 0x7F thing is good to prevent accidentally sending invalid midi, but not necessarily the best thing for setting ranges.
this code will prevent octave shift from exeeding 0x7F and wrapping around 0 for octave up:
unsigned char tmp; ... tmp = octave + 0x0C; if !(tmp & 0x80) octave = tmp;
i supect, though, that what you really need is to keep octave + your highest note value under 0x7f. so, for octave up:#define OCTAVE_MAX 64 ;//set this to 0x7F - 0x0C - your highest note number ... if (octave <= OCTAVE_MAX) octave += 0x0C;
same goes for octave down but with 0
hope this helps...
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[move]I triple-dog dare you[/move]
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woohoo!
that is gonna rock
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http://namm.harmony-central.com/WNAMM08/Content/Line6/PR/ToneCore-Developer-Kit.html
dev kit $199
(ok, not "opensource" as such, but still...)
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tempest rocks, still play regularly on my mame cab.
c'mon "full-blown newb" let's see something before you catch the triple guru curse...
*whack*
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...if anyone wants one, send one dollar...
cool wilba! i'm in for 100.
thanks again d00d!!
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There's no need to worry about this because the original code for sending 3 bytes already deals with this.
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true, as long as you don't mind very high notes becoming very low notes,
or if transposing down, very low notes becoming very high notes
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as tk pointed out to me in this thread ,
there is a risk of sending invalid midi data when transposing
(you want to avoid sending midi data above 0x7F)
in my example i just rapped out of range notes around note 0,
but for your case you might just want to block them...
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i'll trade places w/ wilba, he deserves it and will prolly use them first anywayz
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did you adjust the contrast trim pot?
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is the decoupling electrolytic cap backward on the 7912 input?
the + side should go to gnd (which may be confusing) and the - side to the i 7912 input...
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... (might make you feel a little better)...
that's what i'm talkin bout!
here's my full shot.
note the special attention to general tidiness, which ensures successful completion of projects
This was fun while it was around:
that thing is a great idea, mb-dev_brd...
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no slap for you!
the caps should go "as close as possible" to the power supply pins on the ic's
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power pins for the ics
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woohoo! go lego!
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It would be if they could, but God holds the patent....
clapton patented it?
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You can either use a rectifier or regular 1N4148's diodes. With diodes you need 4 of them.
It will look like this:
1n4148 is a small signal diode, you want power diodes (1n4001, 1n4002, etc)
Anyone noticing errors in what iv'e stated here may slap me! Grin
*slap*
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hmmm that image looks like they might be relabeled to me (the text looks too white, pin 1 orientation is not the same). before this becomes an incident of some kind, and with you being so new to the forum, may i suggest that you send some samples to someone with a good reputation here (seppoman, nILS, Wilba...), who can verify the quality? maybe 10 or so, to be paid for after testing, or returned...
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..........
that sounds to me like "well t...
pblblblblblbblblblblblblblt
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???
i take it you are also confused as to why you posted this in the chat thread...
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cut resistor legs are now considered inhumane and therefor cut resister leads should be used instead by all conscientious boxers, preferably .1% for audio paths...