Post by thread:PWM background

can pwm code on a 16c84 be written to do it in the background? i mean if i wann a set my servo to run forward and my code to continue on its cheking of sensor i nputs while that servo runs forward is it possible? i would think so but im not sure, im used to my first love, 68hc11 :) mike Send someone a cool Dynamitemail flashcard greeting!! And get rewarded. GO AHEAD! http://cards.dynamitemail.com/index.php3?rid=fc-41

Mike M wrote: > can pwm code on a 16c84 be written to do it in the background? i mean if i wa nna set my servo to run forward and my code to continue on its cheking of sensor inputs while that servo runs forward is it possible? > > i would think so but im not sure, im used to my first love, 68hc11 :) > > mike Yes, the PWM machine is a self serving port. And I too have A LOT of time in the MC68HC11. > > > Send someone a cool Dynamitemail flashcard greeting!! And get rewarded. > GO AHEAD! http://cards.dynamitemail.com/index.php3?rid=fc-41 -- Thomas C. Sefranek WA1RHP ARRL Instructor, Technical Specialist, VE Contact. http://www.harvardrepeater.org http://hamradio.cmcorp.com/inventory/Inventory.html

Yes. If you are using standard hobby servos then make a 'state' machine (in other words, code it) so that you keep the servos updated at least every 20 ms and at most about every 12 ms. This gives you lots of time to check out the other pins. Don't need to do interrupts - but you can. An example of tending to the servos (six of them) and using interrupts to catch serial inputs - and keeping within the rather loose timing windows of hobby servos - is at http://204.233.101.40/robots/ssc1684.html You can probably see from the code how to handle two hobby servos and still catch sensor inputs. Dan {Original Message removed}

pic 16c84 does not have a PWM port so your software will not work in the background. I am currently building an ECU for model jets - email of list if you want any further info. Try looking at pic16F87x series. These chips have PWM ports so you dont have to bother with calculating this through the software. (been there done that!) Aaron {Original Message removed}

Mike wrote.. > can pwm code on a 16c84 be written to do it in the background? i mean if i wa nna set my servo to run forward and my code to continue on its cheking of sensor inputs while that servo runs forward is > > i would think so but im not sure, im used to my first love, 68hc11 :) > I haven't done this myself yet but I can't see why a PWM of lowish freq and not too high a resolution couldn't be run from the timer overflow interrupt. This really really depends on what else is going on and as I just said what the specs for you're PWM are. I have always used a PIC with a PWM port such as 16C74 or 16F877 as my applications have had the PIC heavily involved with other activities and I have needed PWM of 10 bits resolution at 20kHz, too much for software alone to handle. I recall someone was running multiple servos off one PIC. Check the archives. _____________________________ Lance Allen Technical Officer Uni of Auckland Psych Dept New Zealand http://www.psych.auckland.ac.nz _____________________________

>Yes, the PWM machine is a self serving port. > What? there is no PWM ports on a 16c84, i assume your are talking about the 68hc 11. On Wed, 17 Nov 1999 11:11:24 -0500 "Thomas C. Sefranek" <spam_OUTtcsTakeThisOuTCMCORP.COM> wrote: >Mike M wrote: > >> can pwm code on a 16c84 be written to do it in the background? i mean if i w anna set my servo to run forward and my code to continue on its cheking of senso r inputs while that servo runs forward is it possible? {Quote hidden}>> >> i would think so but im not sure, im used to my first love, 68hc11 :) >> >> mike > >Yes, the PWM machine is a self serving port. > >And I too have A LOT of time in the MC68HC11. > >> >> >> Send someone a cool Dynamitemail flashcard greeting!! And get rewarded. >> GO AHEAD! http://cards.dynamitemail.com/index.php3?rid=fc-41 > >-- >Thomas C. Sefranek WA1RHP >ARRL Instructor, Technical Specialist, VE Contact. >http://www.harvardrepeater.org >http://hamradio.cmcorp.com/inventory/Inventory.html > Send someone a cool Dynamitemail flashcard greeting!! And get rewarded. GO AHEAD! http://cards.dynamitemail.com/index.php3?rid=fc-41

Mike M wrote: > >Yes, the PWM machine is a self serving port. > > > What? there is no PWM ports on a 16c84, i assume your are talking about the 68 hc11. > Right it's a 16C63A, I have a good memory it's just short. -- Thomas C. Sefranek WA1RHP ARRL Instructor, Technical Specialist, VE Contact. http://www.harvardrepeater.org http://hamradio.cmcorp.com/inventory/Inventory.html

At 08:55 AM 11/18/99 +1200, you wrote: >I haven't done this myself yet but I can't see why a PWM of lowish >freq and not too high a resolution couldn't be run from the timer >overflow interrupt. Yes, it certainly can be done. I did it in a robotics project. Take a look at: http://www.hobbyrobot.com/info/SoccerBot/index.html and specifically the PIC source code http://www.hobbyrobot.com/info/SoccerBot/code/bot11.asm It is true that I only achieved a PWM frequency of a few kHz at 7-bit resolution (I think the maximum possible rate for a 10MHz PIC was about 10kHz for 8 bit resolution). Sean | | Sean Breheny | Amateur Radio Callsign: KA3YXM | Electrical Engineering Student \--------------=---------------- Save lives, please look at http://www.all.org Personal page: http://www.people.cornell.edu/pages/shb7 .....shb7KILLspam@spam@cornell.edu ICQ #: 3329174

Hi, On Wed, 17 Nov 1999, Thomas C. Sefranek wrote: > Mike M wrote: ... > Yes, the PWM machine is a self serving port. Nope. The question referred to 16C84 which has definitely no PWM port. You can do it in a Timer ISR, though. Of course, it'd be better to choose such PIC which does have a built-in PWM generator, e.g. 16C62 and up, I guess. Regards, Imre