LeafLabs Garden » Topic: Advanced Timer Complementary Output Setup

LeafLabs Garden » Topic: Advanced Timer Complementary Output Setup http://forums.leaflabs.com/topic.php?id=2000 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:23:50 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://forums.leaflabs.com/search.php mbolivar on "Advanced Timer Complementary Output Setup" http://forums.leaflabs.com/topic.php?id=2000#post-11502 Mon, 02 Jul 2012 15:03:36 +0000 mbolivar 11502@http://forums.leaflabs.com/ hi emburl, <blockquote> For now I'll post the code </blockquote> thanks for posting! i've often wondered about using the complementary outputs myself, so it's nice to have some working code out there. for longer code listings like your first one, though, please follow the <a href="http://forums.leaflabs.com/topic.php?id=994">guidelines for posting</a> and use pastebin (or something like it) instead of posting them directly. emburl on "Advanced Timer Complementary Output Setup" http://forums.leaflabs.com/topic.php?id=2000#post-11483 Sun, 01 Jul 2012 22:26:33 +0000 emburl 11483@http://forums.leaflabs.com/ So as it turns out, the only thing that was making this problematic was the shared output on pin55. I haven't worked out how to disable at setup time, but to get a complimentary output for testing all thats needed is to initalise both pins as PWM using pinMode and set the CCER bits: Which looks alot nicer.. void setup(){ HardwareTimer timer8 = HardwareTimer(8); timer8.setPrescaleFactor(1); timer8.setOverflow(65535/4); pinMode(13, PWM); //Ideally these would be done as bit wise as I dont know exactly whats being set here.. pinMode(55, PWM); timer_dev *t = TIMER8; //refers t to Timer 8 memory location, how to read back? timer_reg_map r = t->regs; bitSet(r.adv->CCER,0); //this should enable complimentary outputs bitSet(r.adv->CCER,2); } void loop(){ pwmWrite(13, 15000); //should complement on pin55 (Native) pwmWrite(55, 0); //this is just to hold timer3 channel 2 low } emburl on "Advanced Timer Complementary Output Setup" http://forums.leaflabs.com/topic.php?id=2000#post-11482 Sun, 01 Jul 2012 21:27:20 +0000 emburl 11482@http://forums.leaflabs.com/ Cheers Crenn I have been working through the reference manual, (the beefy 1023 document that it is..). not datasheet as I said. I've got it complementing now, although I need to declare both pins as PWM using the pinMode() command, then bitbash away in the registers (its not very elegant at this stage). My issue now is that the complemented output is changing, where the non complement is static, as though the compare value is incrementing for the complemented channel, once it exceeds the threshold. I'll think about it some more and post when I work it out, it probably trivial. For now I'll post the code, Ive set and cleared individual bits explicitly so I could keep track of what was being changed. It may help someone else looking at this. void setup(){ HardwareTimer timer8 = HardwareTimer(8); // timer8.pause(); timer8.setPrescaleFactor(1); timer8.setOverflow(65535/4); timer8.setCount(0); // timer8.refresh(); pinMode(13, PWM); //Not sure what this is seting in the reg's pinMode(55, PWM); timer_dev *t = TIMER8; //refers t to Timer 8 memory location, how to read this back? timer_reg_map r = t->regs; bitClear(r.adv->CR1,0); //disable clock to set centre alligned mode bitClear(r.adv->BDTR,8); //unnlock BDTR register, could probably keep lock level 1 on bitClear(r.adv->BDTR,9); bitClear(r.adv->CCER,0); // clear TIM8_CCER bit 0 to set CCMR bits bitClear(r.adv->CCMR1,0); //This should configure channel1 of Timer8 as an output bitClear(r.adv->CCMR1,1); bitSet(r.adv ->CCMR1,4); //Set PWM mode2 channel 1 timer8 bitSet(r.adv ->CCMR1,5); bitSet(r.adv ->CCMR1,6); bitSet(r.adv ->CCMR1,3); //Set OCPE bit to enable auto reload register bitSet(r.adv -> CR1,7); //Buffer reload register bitSet(r.adv->CR1,5); //These two bits specify one of three centre aligned PWM options bitSet(r.adv->CR1,6); // bitSet(r.adv->EGR,0); //initialise all registers bitSet(r.adv->CCER,0); //this should enable complimentary outputs bitSet(r.adv->CCER,2); bitSet(r.adv->BDTR,11); // OSSR bit bitSet(r.adv->BDTR,15); // MOE bit Cleared by software, probably dont need to set bitSet(r.adv->CR1,0); //clock back on } void loop(){ pwmWrite(13, 15000); //should complement on pin55 } Some of the bit operations are probably redundant due to the pinMode(), p340 and 307 of the STM32F reference manual give alot of info on the required registers crenn on "Advanced Timer Complementary Output Setup" http://forums.leaflabs.com/topic.php?id=2000#post-11480 Sun, 01 Jul 2012 20:31:19 +0000 crenn 11480@http://forums.leaflabs.com/ I haven't used the feature before, but believe you may need to manipulate the timer registers to get the complementary outputs out. For this information, I'd look at the Reference Manual for STM32F1 located here: <a href="http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/REFERENCE_MANUAL/CD00171190.pdf" rel="nofollow">http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/REFERENCE_MANUAL/CD00171190.pdf</a> pinMode() is located in (IDE_Folder)>hardware>leaflabs>cores>maple>wirish_digital.cpp emburl on "Advanced Timer Complementary Output Setup" http://forums.leaflabs.com/topic.php?id=2000#post-11478 Sun, 01 Jul 2012 19:59:35 +0000 emburl 11478@http://forums.leaflabs.com/ Hi Im a relatively new user to the Maple ide (v0.0.12) using a Native board to implement switching control. Ive been looking at the advanced timer functions available on timer1 and 8, in particular the complementary outputs designed for PWM driving of bridge circuits. I started playing with the registers, setting bit values in my Setup() routine following the STM32 datasheet. While I have been able to have some effect on the output on pin 13 (for timer 8 channel 1), I have not been able to produce the output complement on pin 55 (where timer 8 channel1N is mapped to). (I have tried to disable the counter output of timer 3 channel 2 that shares the pin) a) Has anyone been able to access this feature? b) This could be very obvious but I cant find it, where can I see the source code for the pinMode() routines? If there is a better way to do this, Im all ears (Im sure there is)