http://forums.leaflabs.com/topic.php?id=2266 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:20:17 +0000 http://bbpress.org/?v=1.0.2 q http://forums.leaflabs.com/search.php http://forums.leaflabs.com/topic.php?id=2266#post-12028 Thu, 26 Jul 2012 16:01:38 +0000 dapoup 12028@http://forums.leaflabs.com/ <p>Thanks a lot for this clear answer. </p> http://forums.leaflabs.com/topic.php?id=2266#post-12002 Wed, 25 Jul 2012 16:02:32 +0000 mbolivar 12002@http://forums.leaflabs.com/ <p>Note that the clock tree on the Maple is highly configurable. These answers apply only to the Maple's default clock tree configuration (which most people don't mess with).</p> <blockquote><p> 1 - Prescaler : This is the division ratio applied to the timer tick clock, right?</p> </blockquote> <p>Yes, that's right. So a prescaler of 1 counts at the clock speed, 2 means two clock ticks per timer counter change, etc. A prescaler of 1 counts at the max rate of 72 MHz.</p> <blockquote><p> 2 - Overflow : This is the value at the one you overflow, or the salue that the counter is set to when it overflows?</p> </blockquote> <p>It's the counter value that causes an overflow. The Maple default is for the counter to reset to zero after it overflows.</p> <blockquote><p> ==&gt; What I understand : timer.setOverflow(65535) sets the counting to its full range, allowing the PWM to be operated in its full scale?</p> </blockquote> <p>Not sure what you mean by "full scale". But yes, setting the overflow to that value means you can set the compare to any value between 0 and 65535. 65535 (=2^16-1) is the greatest legal overflow value.</p> <blockquote><p> 3 - Compare : is it this buffer, in PWM mode, that stores the value to be compared to for PWM output?</p> </blockquote> <p>Yes. The compare value determines the duty cycle. Specifically, the duty cycle is the ratio of the compare value to the overflow value. </p> http://forums.leaflabs.com/topic.php?id=2266#post-11968 Tue, 24 Jul 2012 09:00:14 +0000 dapoup 11968@http://forums.leaflabs.com/ <p>Dear all,</p> <p>Please find herebelow a bunch of Noob-baked questions, from a newcomer that want everything to be cristal clear before going on.</p> <p>I want to do 16bits PWM audio output, using the Timer #1 to do so. First, I set the pin 6 as a PWM output. That's for the sketch setup.</p> <p>Then, concerning the Timer Setup:</p> <p>1 - Prescaler : This is the division ratio applied to the timer tick clock, right?</p> <p>==&gt; What I inderstand : timer.setPrescaleFactor(1) sets the Timer counting clock to 72Mhz? Or maybe the cristal 8Mhz?</p> <p>2 - Overflow : This is the value at the one you overflow, or the salue that the counter is set to when it overflows?</p> <p>==&gt; What I understand : timer.setOverflow(65535) sets the counting to its full range, allowing the PWM to be operated in its full scale?</p> <p>3 - Compare : is it this buffer, in PWM mode, that stores the value to be compared to for PWM output?</p> <p>==&gt; What I understand : timer.setChannel1Mode(TIMER_PWM)and timer.setCompare(TIMER_CH1, 32768) should generate a square wave at the output of pin 6 of the board?</p> <p>Thanks in advance for your kind highlights on those foggy points (at least, to me...).</p> <p>dapoup </p>