Searching \ for 'PWM background' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/io/pwm/index.htm?key=pwm
Search entire site for: 'PWM background'.

Truncated match.
PICList Thread
'PWM background'
1999\11\17@110334 by Mike M

flavicon
face
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

1999\11\17@111403 by Thomas C. Sefranek

face picon face
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

1999\11\17@120057 by Dan Creagan

flavicon
face
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}

1999\11\17@133141 by Aaron

flavicon
picon face
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}

1999\11\17@145534 by l.allen

picon face
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

_____________________________

1999\11\17@153120 by Mike M

flavicon
face
>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_OUTtcsTakeThisOuTspamCMCORP.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}

Send someone a cool Dynamitemail flashcard greeting!! And get rewarded.
GO AHEAD! http://cards.dynamitemail.com/index.php3?rid=fc-41

1999\11\17@164207 by Thomas C. Sefranek

face picon face
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

1999\11\17@172547 by Sean Breheny

face picon face
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
.....shb7KILLspamspam@spam@cornell.edu ICQ #: 3329174

1999\11\18@045701 by Dr. Imre Bartfai

flavicon
face
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

More... (looser matching)
- Last day of these posts
- In 1999 , 2000 only
- Today
- New search...