http://forums.leaflabs.com/topic.php?id=1129 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:22:55 +0000 http://bbpress.org/?v=1.0.2 q http://forums.leaflabs.com/search.php http://forums.leaflabs.com/topic.php?id=1129#post-6954 Sun, 23 Oct 2011 16:07:14 +0000 gbulmer 6954@http://forums.leaflabs.com/ <p>samtal - According to the RM0008 manual, in section 15.3.2 "Counter modes", there are several ways to do this without any interrupt.<br /> The simplest solution looks like setting the counter for the whole timer block (using pre-scalar and auto-reload value) so that you can see the event in the timers registers</p> <p>You could just poll the appropriate bit directly (I think it is the UIF bit 15.4.5 "TIMx status register (TIMx_SR)", but I haven't read that carefully enough to be sure. Pulling directly using something like like a register address.)</p> <p>The alternative is to write a tiny interrupt handler which sets a 'flag'.<br /> The documentation is at <a href="http://leaflabs.com/docs/lang/api/hardwaretimer.html#using-timer-interrupts" rel="nofollow">http://leaflabs.com/docs/lang/api/hardwaretimer.html#using-timer-interrupts</a></p> <pre><code>HardwareTimer timer(2); volatile int flag = 0; void setup() { // set up timer // attach interrupt timer.attachCompare1Interrupt(timer2interrupt); } void loop() { //... flag = 1; while (flag) ; // wait for the flag to clear, and hence synchronise flag = 1 for (int i = 0; i&lt;100;i++) { while (flag !=0) //Wait until timer fires (resets to 0 or other). timearray[i]=micros(); flag = 1; } } void timer2interrupt() { flag = 0; }</code></pre> http://forums.leaflabs.com/topic.php?id=1129#post-6948 Sat, 22 Oct 2011 13:50:04 +0000 samtal 6948@http://forums.leaflabs.com/ <p>I have a 'for' loop in which I wish to do something (for test, make a time reading) each predefined time interval of several tens micros.<br /> I initialize a hardware compare timer, define interrupt handler, sets the period and starts the timer in the setup.<br /> I expect the loop to halt in each cycle until the timer reaches a certain value (0 or any) and then make the next loop.<br /> At the end of the loop number, the program is expected to exit the loop and proceed in the main loop, until the function will be called again.<br /> Here is a basic example of what I need:</p> <p>void program()<br /> {<br /> for (int i = 0; i&lt;100;i++)<br /> {<br /> while (timer !=0) //Wait until timer fires (resets to 0 or other).</p> <p> timearray[i]=micros();<br /> }<br /> }<br /> I assume I need to use an interrupt(?), but I can not use an external function, as I want the interrupt inside my function.<br /> Does anyone know how I can make this work?<br /> Thanks<br /> samtal </p>