Kermit's Content
There have been 78 items by Kermit (Search limited from 19-May 23)
#28805 TLC5940
Posted by
on 11 May 2012 - 10:10 AM
in
General Discussion
#28815 TLC5940
Posted by
on 11 May 2012 - 12:33 PM
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#28785 TLC5940
Posted by
on 10 May 2012 - 08:45 PM
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#28780 TLC5940
Posted by
on 10 May 2012 - 05:55 PM
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#28770 TLC5940
Posted by
on 10 May 2012 - 11:37 AM
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#28831 TLC5940
Posted by
on 11 May 2012 - 03:55 PM
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#28848 TLC5940
Posted by
on 11 May 2012 - 06:29 PM
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#29049 TLC5940
Posted by
on 14 May 2012 - 09:15 PM
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#29024 TLC5940
Posted by
on 14 May 2012 - 03:31 PM
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#29022 TLC5940
Posted by
on 14 May 2012 - 03:20 PM
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#28851 TLC5940
Posted by
on 11 May 2012 - 07:17 PM
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#28747 TLC5940
Posted by
on 09 May 2012 - 08:16 PM
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#28745 TLC5940
Posted by
on 09 May 2012 - 08:14 PM
in
General Discussion
Goedenavond
According to the schematic, it's not such a difficult set-up.
The 2k2 resistors are, according to the description "to make this board suitable for use with servos".
This is really strange: at the end of page 14 of the datasheet (http://www.ti.com/li...ink/tlc5940.pdf) there is the formula to use for the resistor.
Iout = 39.06 / R (simplified)
with the range of 5mA and 120mA.
I use a 100 Ohm resistor (but I could never light any led!) giving an output of 39mA, with your resistor you should have 0.017mA, way under the lower limit.
Are you sure there are no other components wired to Iref?
Andrea
#28505 TLC5940
Posted by
on 03 May 2012 - 06:56 PM
in
General Discussion
#28519 TLC5940
Posted by
on 03 May 2012 - 10:29 PM
in
General Discussion
What puzzles me is that I've tried two sources I found in internet:
- http://tlc5490netduino.codeplex.com/
- http://forums.netdui...940-pwm-driver/
but neither one has the wiring diagram. It's really strange that programmers so kind to share their code don't think to inexpert people like me: or I'm so inexpert to not see something obvious... :-)
Everywhere I look I find some different detail, on the wiring, so that it's even impossible to try every combination!
Andrea
#28503 TLC5940
Posted by
on 03 May 2012 - 06:41 PM
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#28498 TLC5940
Posted by
on 03 May 2012 - 04:55 PM
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#28496 TLC5940
Posted by
on 03 May 2012 - 04:40 PM
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#28532 TLC5940
Posted by
on 04 May 2012 - 07:20 AM
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#28536 TLC5940
Posted by
on 04 May 2012 - 08:44 AM
in
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#28738 TLC5940
Posted by
on 09 May 2012 - 07:16 PM
in
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#28734 TLC5940
Posted by
on 09 May 2012 - 06:55 PM
in
General Discussion
#28733 TLC5940
Posted by
on 09 May 2012 - 06:54 PM
in
General Discussion
Ok, let's start with that. I think the driver will need some work still. I'll post code and pictures when I get back home tonight.
I hope to find you online... in which timezone are you? What do you mean by 'tonight'? :-)
Andrea
#28710 TLC5940
Posted by
on 09 May 2012 - 11:29 AM
in
General Discussion
I'm working on a driver for the Tlc5940 for Netduino. I use the PWM ports from the Netduino to control the BLANK and GSCLK cycles, and the output looks pretty smooth to me, no flicker whatsoever. I have a GSCLK period of 2 microseconds, BLANK on 4096 times that, so roughly 10 ms per PWM cycle. Communication on the SPI port runs at about 40 MHz (if I can believe the documentation
), I don't see any noticable interruptions when switching the signals.
I use a shield from Sparkfun, not all pins are exposed there (notably VPRG), but for now it'll do. I actually wanted to ask if there is anyone interested in code like this. Maybe I should just put it on Sourceforge?
...mmmmmmm... why do you think I could be interested? :-))))))))))
Apart from jokes, I already thank you so much, moreover, I hope you can share the schematic too, I'm only a software guy, and I found a lot of problems to wire cables and components correctly...
I'm *really* waiting for you! :-)
Thanks again
Andrea
P.S. You can also attach files just here... :-)
#28495 TLC5940
Posted by
on 03 May 2012 - 04:32 PM
in
General Discussion
I found a small but interesting document here: TLC5940 One-Wire Control, where, with an apparently simple wiring, I should be able to turn on and off the entire block of LEDs. The only interesting page is page 3, even if the whole document is there.
I wired the chip in this way:
and used this code to try to get the led flashing:
Thread.Sleep(300);
var gsclk = new OutputPort(Pins.GPIO_PIN_D0, false);
var blank = new OutputPort(Pins.GPIO_PIN_D1, true);
Thread.Sleep(200);
bool enable = false;
while (enable)
{
blank.Write(enable);
Thread.Sleep(1);
gsclk.Write(!enable);
Thread.Sleep(2000);
enable = !enable;
}
Here I'm supposing I can use the Netduino to turn high and low the two signals GSCLK and BLANK, with a simple delay, as suggested by the document (it uses a subcircuit, there).
The other difference is the capacitor in the bottom of the figure, between Vcc and ground: there are no numbers, and I suppose it's there to stabilize input voltage (or not?).
Please, is there someone who can give a look and enlighten me on anything that can be wrong?
Thanks again.
Andrea
