get information of angle from servo
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Posts: 46,084
Hello
Does it is possible get information of angle from servo motor?.
for example , twist the horn and then information of angle will
shows in screen.
I tried serin and serout, and it seem didnt work.
If possible, would you tell me more about detail? Like schematic
and example.
(someone told me that I can use encoder or some sort of resistor
circuit.But I dont understand what he said(I major in biology)
Thanks in advance!
ps: my stamp is 2sx and 2
Does it is possible get information of angle from servo motor?.
for example , twist the horn and then information of angle will
shows in screen.
I tried serin and serout, and it seem didnt work.
If possible, would you tell me more about detail? Like schematic
and example.
(someone told me that I can use encoder or some sort of resistor
circuit.But I dont understand what he said(I major in biology)
Thanks in advance!
ps: my stamp is 2sx and 2
Comments
(including a method of getting the information back to the host) onto
the servo. If you can mechanically link a potentiometer to the servo
shaft, you could use the RCTIME instruction or an external A2D converter
to read the position.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: john [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9TnkpLR2UteF0XfJKXQZX3ON6iccyyW3bRqb2yIMcHoVw7ze97vLJTutHgMPmGQXOChbsZef8Xn9oS-O4nMVTjt_jmr8uw]w3102008@m...[/url
Sent: Saturday, April 10, 2004 5:36 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] get information of angle from servo
Hello
Does it is possible get information of angle from servo motor?.
for example , twist the horn and then information of angle will
shows in screen.
I tried serin and serout, and it seem didnt work.
If possible, would you tell me more about detail? Like schematic
and example.
(someone told me that I can use encoder or some sort of resistor
circuit.But I dont understand what he said(I major in biology)
Thanks in advance!
ps: my stamp is 2sx and 2
> for example , twist the horn and then information of angle will
> shows in screen.
Not without modifying the servo. Servo's are "open loop" in that you tell
them where you want them to be and they turn to that position; There isn't
any feedback to you that it's actually at the position unless you add
hardware + electronics to do that.
> If possible, would you tell me more about detail? Like schematic
> and example.
Internally to the servo the electronics work by comparing a voltage that's
represents where you want the servo positioned to another voltage that's
generated by a variable resistor that's connected to the shaft of the servo.
If these two values differ then the electronics drive the motor in the
direction that will make these two values equal. (It's uses the difference
between the two values to drive the motor. The bigger the difference the
faster it drives the motor.)
If you could connect a wire to the wiper arm of the variable resistor then
you could read its voltage to determine the position of the servo shaft from
that. You would then need some kind of analog to digital (AD) converter to
get a value into the computer that you could use.
--
Enjoy,
George Warner,
Schizophrenic Optimization Scientists
Apple Developer Technical Support (DTS)
> Hello
> Does it is possible get information of angle from
> servo motor?.
> for example , twist the horn and then information
> of angle will
> shows in screen.
Servos are output devices only. So you can't read the
position with an encoder. Perhaps a shaft encoder.
=====
Chris Savage
Knight Designs
324 West Main Street
Montour Falls, NY 14865
(607) 535-6777
http://www.knightdesigns.com
__________________________________
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and direction (two opto-couplers on a disk can tell direction info). Those
are closed-loop servos. Others have lookup tables and simply position
without feedback. Those are open-loop servo's.
>
Original Message
> From: George Warner [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=PD-VWoK5pJmMglTyyEdzcZyvN2nYeYWmdxjmmBssZv_Ou_c_vjorDSA7lWO8nGNBwTgI-3C3_EU]geowar@a...[/url
> Sent: Saturday, April 10, 2004 5:18 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] re: get information of angle from servo
>
> > Does it is possible get information of angle from servo motor?.
> > for example , twist the horn and then information of angle will
> > shows in screen.
>
> Not without modifying the servo. Servo's are "open loop" in that you tell
> them where you want them to be and they turn to that position; There isn't
> any feedback to you that it's actually at the position unless you add
> hardware + electronics to do that.
>
> > If possible, would you tell me more about detail? Like schematic
> > and example.
>
> Internally to the servo the electronics work by comparing a voltage that's
> represents where you want the servo positioned to another voltage that's
> generated by a variable resistor that's connected to the shaft of the
> servo.
> If these two values differ then the electronics drive the motor in the
> direction that will make these two values equal. (It's uses the difference
> between the two values to drive the motor. The bigger the difference the
> faster it drives the motor.)
>
> If you could connect a wire to the wiper arm of the variable resistor then
> you could read its voltage to determine the position of the servo shaft
> from
> that. You would then need some kind of analog to digital (AD) converter to
> get a value into the computer that you could use.
>
> --
> Enjoy,
> George Warner,
> Schizophrenic Optimization Scientists
> Apple Developer Technical Support (DTS)
>
>
>
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