http://forums.leaflabs.com/topic.php?id=1196 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:18:28 +0000 http://bbpress.org/?v=1.0.2 q http://forums.leaflabs.com/search.php http://forums.leaflabs.com/topic.php?id=1196#post-7306 Sun, 11 Dec 2011 23:16:41 +0000 ericyanush 7306@http://forums.leaflabs.com/ <p>Finally, after hours and hours of timer issues (and many forcibly removed hairs) I have my Maple Mini interfacing properly with a TLC5940 using SPI and two Hardware Timers. As soon as I get some more testing done, and Clean up the code I will post it. </p> http://forums.leaflabs.com/topic.php?id=1196#post-7302 Sun, 11 Dec 2011 06:15:58 +0000 ericyanush 7302@http://forums.leaflabs.com/ <p>I have been doing some work on getting the TLC5940 working with Maple too. As of right now I can shift the data out using SPI, but I am running into a timing problem setting up hardware timers to take care of pulsing the GSCLK and firing an interrupt every 4096 pulses to clock in more data, so the channels are always either on or off no matter the DC or GS value it has set. :( </p> http://forums.leaflabs.com/topic.php?id=1196#post-7269 Thu, 01 Dec 2011 13:54:15 +0000 gbulmer 7269@http://forums.leaflabs.com/ <p>nissarup - I haven't checked that code at all.<br /> I just wrote it off the top of my head to illustrate the idea, after a quick glance at the TLC5490 datasheet.<br /> It looks okay, but I wouldn't be surprised if I'd missed something. </p> <p>Also, the call to <code>digitalWrite()</code> is so slow that <code>delayMicroseconds()</code> is probably not needed. </p> http://forums.leaflabs.com/topic.php?id=1196#post-7268 Thu, 01 Dec 2011 07:25:53 +0000 nissarup 7268@http://forums.leaflabs.com/ <p>That was what I figured last night that I would do today.<br /> Thank you for the snippet. </p> http://forums.leaflabs.com/topic.php?id=1196#post-7266 Wed, 30 Nov 2011 16:40:48 +0000 gbulmer 7266@http://forums.leaflabs.com/ <p>nissarup - if you are having problems, you might want to try 'bit banging' the interface to the TLC5490. Use digitalWrite to generate a clock and data signals.</p> <p>E.g.:<br /> <pre><code>const byte dataPin = 9; // a random guess const byte clockPin = 10; // another random guess void dummySPIwrite(byte b) { for (byte bitMask=0b10000000; bitMask != 0; bitMask &gt;&gt;= 1) { digitalWrite(clockPin, LOW); digitalWrite(dataPin, (b &amp; bitMask)? HIGH : LOW); delayMicroseconds(1); digitalWrite(clockPin, HIGH); delayMicroseconds(1); } digitalWrite(clockPin, LOW); }</code></pre> <p>This technique may be enough to get you off the ground, and test the electronics.<br /> Have you access to an oscilloscope? You might also have a look at the signals to see that they make sense.</p> <p>(full disclosure: I am not a member of LeafLabs staff.)<br /> (WARNING: I have not compiled and tested that code.) </p> http://forums.leaflabs.com/topic.php?id=1196#post-7264 Wed, 30 Nov 2011 08:51:56 +0000 nissarup 7264@http://forums.leaflabs.com/ <p>Hi all,</p> <p>Have anybody interfaced a Maple with the TLC5490 LED driver?<br /> It's supposed to be reachable via SPI, but I've had no luck so far.</p> <p>--Nis </p>