victor 883 motor driver PWM signal problems
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I have three victor 883 motor drivers from IFI. Two used to work
with my pak-VIII (they received the PWM signal and acted
accordingly). One, right out of the box, sometimes shows that it's
receiving a signal either right when I power up the stamp which is
controlling the pak (and giving the pak power from it's 5V output),
or when I activate the appropriate pak channel (which corresponds
with the victor). But Once I start actually sending pwm to this
victor, it stops receiving any signal.
Recently, another one of my three victors started acting exactly
the same. I sent both in for repairs and the guy sent them both back
saying that they were acting fine when he tested them... I have a
feeling it has to do with the power of the signal coming from the
pak. Anyone else have a similar problem and was able to fix it? The
people at IFI aren't very helpful. They just tell you that it's
working whether it's working with my system or not. Thanks
with my pak-VIII (they received the PWM signal and acted
accordingly). One, right out of the box, sometimes shows that it's
receiving a signal either right when I power up the stamp which is
controlling the pak (and giving the pak power from it's 5V output),
or when I activate the appropriate pak channel (which corresponds
with the victor). But Once I start actually sending pwm to this
victor, it stops receiving any signal.
Recently, another one of my three victors started acting exactly
the same. I sent both in for repairs and the guy sent them both back
saying that they were acting fine when he tested them... I have a
feeling it has to do with the power of the signal coming from the
pak. Anyone else have a similar problem and was able to fix it? The
people at IFI aren't very helpful. They just tell you that it's
working whether it's working with my system or not. Thanks
Comments
different things. First, check to make sure you have common grounds
everywhere and preferably tied back to one common location (a "star"
ground). Second, decoupling capacitors. With motors you need a big
capacitor across the supply to smooth out the brown outs. In addition,
consider putting a .1uF and a .001 uF near the PAK (between Vdd and
Vss). On paper, it looks like that just creates a .101uF capacitor, but
in real life it provides different pathways for different frequency
noise.
You might also want to put capacitors near the motor's power leads (not
the PWM leads).
That's just a guess....
Al Williams
AWC
* 8 channels of PWM
http://www.al-williams.com/awce/pak5.htm
>
Original Message
> From: Sam [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=8QgQ50SnVQkNyu_rFMLhTYHuoRxromzW7DtvVe6NuxUgvwhjnG2-_TTUcVMyed3Fh3NSW5uJtIykGA]hard-on@t...[/url
> Sent: Friday, August 22, 2003 8:15 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] victor 883 motor driver PWM signal problems
>
>
> I have three victor 883 motor drivers from IFI. Two used to work
> with my pak-VIII (they received the PWM signal and acted
> accordingly). One, right out of the box, sometimes shows that it's
> receiving a signal either right when I power up the stamp which is
> controlling the pak (and giving the pak power from it's 5V output),
> or when I activate the appropriate pak channel (which corresponds
> with the victor). But Once I start actually sending pwm to this
> victor, it stops receiving any signal.
> Recently, another one of my three victors started acting exactly
> the same. I sent both in for repairs and the guy sent them both back
> saying that they were acting fine when he tested them... I have a
> feeling it has to do with the power of the signal coming from the
> pak. Anyone else have a similar problem and was able to fix it? The
> people at IFI aren't very helpful. They just tell you that it's
> working whether it's working with my system or not. Thanks
>
>
> To UNSUBSCRIBE, just send mail to:
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>
never used a Stamp to drive them though. I use dedicated used to drive
them. The IFI people do say from time to time in their documents, that some
microcontrollers don't supply enough current to the Victor's to drive them
properly. This is why they sell a signal booster. I don't know if this is
the problem.
If I remember right, the Victor's PWM input signals are optically isolated
from the H-Bridge drive circuits, so you don't need to use a common ground.
Pete Miles
Original Message
From: "Sam" <hard-on@t...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, August 22, 2003 6:15 AM
Subject: [noparse][[/noparse]basicstamps] victor 883 motor driver PWM signal problems
> I have three victor 883 motor drivers from IFI. Two used to work
> with my pak-VIII (they received the PWM signal and acted
> accordingly). One, right out of the box, sometimes shows that it's
> receiving a signal either right when I power up the stamp which is
> controlling the pak (and giving the pak power from it's 5V output),
> or when I activate the appropriate pak channel (which corresponds
> with the victor). But Once I start actually sending pwm to this
> victor, it stops receiving any signal.
> Recently, another one of my three victors started acting exactly
> the same. I sent both in for repairs and the guy sent them both back
> saying that they were acting fine when he tested them... I have a
> feeling it has to do with the power of the signal coming from the
> pak. Anyone else have a similar problem and was able to fix it? The
> people at IFI aren't very helpful. They just tell you that it's
> working whether it's working with my system or not. Thanks
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
Al,
Would that PAK5 servo copressor be able to update 6 servos in real time? What
would be the refresh rate? Do you have a RF link that will connect the two(a
BS2 & PAK 5)?
thanks,
Leroy
N8VRC
BTW thinking of using it to Fly my Helicopter, but don't like the radios
available, thinking of making my own.
Actually, I think you would want a PAK-VIII to control servos. The PAK-V
puts out PWM best-suited for controlling a light or a DC motor. The
PAK-VIII can do PWM but it can also output fixed time slices that you
want when controlling servos.
As for an RF link, I don't have any knowledge of that. However, the
protocol is simple enough (see http://www.al-williams.com/pakif.htm). I
would imagine any of the cheap RF transmitter/receiver pairs could be
made to do this. If you wanted RS232, the trick would be to have the
processor on board and then talk to the processor.
Good luck!
Al Williams
AWC
* Control 8 servos at once
http://www.al-williams.com/awce/pak8.htm
>
Original Message
> From: Leroy Hall [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=hGO_D1Dm6BI8QQrP8L0fpme0_m7lUUy8J_IfaJ-76XbYXD4EYo715GH5MWqhvflr5XPSrkUp7zo]leroy@f...[/url
> Sent: Friday, August 22, 2003 7:44 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] victor 883 motor driver PWM signal problems
>
>
> This message mainly for Al Williams,
>
> Al,
>
> Would that PAK5 servo copressor be able to update 6 servos in
> real time? What would be the refresh rate? Do you have a RF
> link that will connect the two(a BS2 & PAK 5)?
>
> thanks,
>
> Leroy
> N8VRC
>
> BTW thinking of using it to Fly my Helicopter, but don't like
> the radios available, thinking of making my own.
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
>