4317 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:22:29 +0000 http://bbpress.org/?v=1.0.2 q http://forums.leaflabs.com/search.php http://forums.leaflabs.com/topic.php?id=1121#post-24578 Tue, 16 Apr 2013 13:17:34 +0000 mlundinse 24578@http://forums.leaflabs.com/ <p>I have checked the timings for the delay_us loop and<br /> measured the time for 1000 and 2000 us delays using a<br /> simple oscilloscope.<br /> With a Olimexino STM32, Maple clone, I get accurate delays<br /> (as good as I can measure) using </p> <p># define STM32_DELAY_US_MULT 12 /* When running from flash. */</p> <p># define STM32_DELAY_US_MULT 18 /* When running from RAM. */</p> <p>In Maple-IDE there is at the moment no clean way to switch between these alternatives.<br /> When using the command line tools a compiler flag should work<br /> -DSTM32_DELAY_US_MULT=18</p> <p>Regards<br /> Magnus </p> http://forums.leaflabs.com/topic.php?id=1121&page=2#post-20710 Wed, 31 Oct 2012 20:46:05 +0000 gbulmer 20710@http://forums.leaflabs.com/ <p>bnewbold - as I understand LeafLabs plans <a href="http://leaflabs.com/2011/11/were-teaming-up-with-wiring/" rel="nofollow">http://leaflabs.com/2011/11/were-teaming-up-with-wiring/</a><br /> the upstream reference will be Wiring. So I guess we need to get them to fix this :-) </p> http://forums.leaflabs.com/topic.php?id=1121#post-20699 Wed, 31 Oct 2012 12:50:52 +0000 bnewbold 20699@http://forums.leaflabs.com/ <p>This is a known problem with the upstream Arduino implementation as well:</p> <p><a href="https://code.google.com/p/arduino/issues/detail?id=576" rel="nofollow">https://code.google.com/p/arduino/issues/detail?id=576</a></p> <p>At a minimum, a note in the docs would be nice ;)</p> <p><a href="http://leaflabs.com/docs/lang/api/delaymicroseconds.html#caveats-and-known-issues" rel="nofollow">http://leaflabs.com/docs/lang/api/delaymicroseconds.html#caveats-and-known-issues</a> </p> http://forums.leaflabs.com/topic.php?id=1121#post-8142 Thu, 09 Feb 2012 01:07:19 +0000 joet 8142@http://forums.leaflabs.com/ <p>Konan,</p> <p>Would you be willing to share your reworked IRremote library with me?<br /> I'm getting tripped up right away with the #include &lt;avr/interrupt.h&gt; line...not sure what to do about this.</p> <p>email: <a href="mailto:jtostenrude@hotmail.com">jtostenrude@hotmail.com</a></p> <p>Thanks,<br /> Joe </p> http://forums.leaflabs.com/topic.php?id=1121#post-7235 Thu, 24 Nov 2011 17:29:55 +0000 gbulmer 7235@http://forums.leaflabs.com/ <p>mbolivar<br /> <blockquote>We want delay() and delayMicroseconds() to work even with SysTick disabled.</p></blockquote> <p>Why? What is the rationale?</p> <p>I would prefer delay and delayMicroseconds to be:<br /> a. accurate, and<br /> b. deterministic, with no jitter.<br /> Busy-wait loops will not give that.</p> <p>I have no problem with the principle of busy-wait delays, just that they are harder to use and debug because they suffer jitter from interrupts, such as printing debugging messages. </p> <p>As long as millis() and micros() are hardware-timer-based timing mechanisms, I am okay.<br /> I would prefer delay(), and delayMicroseconds() to have comparable results to using millis() and micros() with a busy wait loop, but that is a question of taste. The fact that they jitter, which can make them somewhat tricky to use, could be mentioned in the documentation.</p> <p>Maybe we could add low-jitter delay functions, with different names? </p> http://forums.leaflabs.com/topic.php?id=1121#post-7234 Thu, 24 Nov 2011 16:18:10 +0000 konan 7234@http://forums.leaflabs.com/ <p>mbolivar, </p> <p>As for patch - I'd love to do my best to make the Maple project better, but now I have absolutely no spare time :( </p> <p>I've ported (and reworked) IRremote library, so I can send you sources and brief description to include it in next IDE release, if you wish. I didn't touch the main routine - signal detection, although I strongly unlike that it use 50us interrupt (and occupies a timer) instead of tiying interrupt to the input pin. But it's a TODO item for the next release :) </p> http://forums.leaflabs.com/topic.php?id=1121#post-6921 Thu, 20 Oct 2011 21:54:05 +0000 mbolivar 6921@http://forums.leaflabs.com/ <p>konan,</p> <p>Looks like you're right. I'm measuring delay times lower than we would expect. I'm reluctant to replace with a micros()-based impplementation, however, as that relies on SysTick. We want delay() and delayMicroseconds() to work even with SysTick disabled. I think we should stick with the delay loop, but it obviously needs to be fixed.</p> <p>If you'd like to submit a patch to fix this, please do! See "contributing to libmaple":</p> <p><a href="http://leaflabs.com/docs/libmaple/contributing.html" rel="nofollow">http://leaflabs.com/docs/libmaple/contributing.html</a> </p> http://forums.leaflabs.com/topic.php?id=1121#post-6891 Mon, 17 Oct 2011 17:34:10 +0000 konan 6891@http://forums.leaflabs.com/ <p>And one more issue with delayMicroseconds(). I found that its actual delay time is very far from that I said to do. So, I tried instead of delayMicroseconds this routine:</p> <p> uint32 a = micros();<br /> while (micros() &lt; a + time) {};</p> <p>which works quite well. I think something really wrong with delayMicroseconds... </p> http://forums.leaflabs.com/topic.php?id=1121#post-6890 Mon, 17 Oct 2011 16:34:52 +0000 konan 6890@http://forums.leaflabs.com/ <p>Hi all, i'm porting to Maple the IRremote library by Ken Shiriff (<a href="http://www.arcfn.com/2009/08/multi-protocol-infrared-remote-library.html)" rel="nofollow">http://www.arcfn.com/2009/08/multi-protocol-infrared-remote-library.html)</a>, and spent last 2 hours trying to find the hang-up point in the IR sending routine. It was the call delayMicroseconds(0), which calls the delay_us function in the delay.h, and in the delay_us there is a line "us--;". So, if I want delay 0 microseconds, I get delay more than hour :)</p> <p>Maybe it would better to make zero-test at the beginning of the delay_us? </p>