Shop OBEX P1 Docs P2 Docs Learn Events
3-Questions — Parallax Forums

3-Questions

ArchiverArchiver Posts: 46,084
edited 2000-05-21 21:57 in General Discussion
I'm trying to control multiple servos from a BS2 and ran across three problems. The servos are the Hitec HS300BB.
1. I was trying to use a voltage regulator to obtain 6+ volts from a 12volt source.· I was using a LM317T with the appropriate resistors in the circuit, according to the package diagram. Connecting the circuit to a meter I read 6.7 volts.· Connecting that circuit to the servo reads 2.7 volts.· For·a novice is this an indication that the servo is drawing more amps than the regulator can handle?· If so what would be a good way to achieve a 6 volt output? The intent is a mobile device running off of one 12 volt source.
2.After giving up on the 6volt problem I went ahead and connected the servo to a 6 volt source and the signal pin to the BS2.· I used a simple program to determine the Pulsout Factor to position the servo:
· For X = 1 to 30
··· pulsout pin#, Value
··· pause 20
return
When I ran the program no matter what Value I entered the servo would rotate in one direction to the extreme position, same direction.
I tried a resistor in the signal line with no difference.· Being an electrical novice what is happening?·
3. Finally I noticed that the servo moved very slowly,· I checked the voltage and it read 6 volts, I tried different servos with the same results.
Any help would be appreciated.
Thanks a bunch.
Brian

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-05-21 01:51
    First off, 1 to 30 is a very low number for a standard servo. Most servos
    have about 1.5 ms center pulse. To get that with a BS2 you'd say
    pulsout pin#,750

    Try numbers up in that range. As for your servos running slowly, the speed
    is proportional to the amount they have to turn. If it is a long way they
    will turn fast, short way they will turn slower. Maybe that's your problem.
    -William


    Original Message
    From: Brian & Sandy McMillion <brianmcm@w...>
    To: Stamps Forum <basicstamps@egroups.com>
    Sent: Saturday, May 20, 2000 6:33 PM
    Subject: [noparse][[/noparse]basicstamps] 3-Questions


    I'm trying to control multiple servos from a BS2 and ran across three
    problems. The servos are the Hitec HS300BB.
    1. I was trying to use a voltage regulator to obtain 6+ volts from a 12volt
    source. I was using a LM317T with the appropriate resistors in the circuit,
    according to the package diagram. Connecting the circuit to a meter I read
    6.7 volts. Connecting that circuit to the servo reads 2.7 volts. For a
    novice is this an indication that the servo is drawing more amps than the
    regulator can handle? If so what would be a good way to achieve a 6 volt
    output? The intent is a mobile device running off of one 12 volt source.
    2.After giving up on the 6volt problem I went ahead and connected the servo
    to a 6 volt source and the signal pin to the BS2. I used a simple program
    to determine the Pulsout Factor to position the servo:
    For X = 1 to 30
    pulsout pin#, Value
    pause 20
    return
    When I ran the program no matter what Value I entered the servo would rotate
    in one direction to the extreme position, same direction.
    I tried a resistor in the signal line with no difference. Being an
    electrical novice what is happening?
    3. Finally I noticed that the servo moved very slowly, I checked the
    voltage and it read 6 volts, I tried different servos with the same results.
    Any help would be appreciated.
    Thanks a bunch.
    Brian
  • ArchiverArchiver Posts: 46,084
    edited 2000-05-21 17:56
    In response to the 12V 6V thing i cant thing of anything. But in the second
    problem I have some questions for you.
    1. did you modify the servo to run contiuously or is it a stock servo?
    2.What values are you using for your Value #?

    Now some suggestions
    If it is a modified servo make sure that either the 2 resistors you used are
    extremely close in actual value. Or make sure that the potentiometer is
    exactly centered
    The resistor you put in the line should be between Signal and Ground. And
    the value should be 10K.
    The values for using servos range between 500-1000 having 750 as center. so
    if you input 750 as the value to a stock servo you should have it stand
    completely still.


    The third problem might just be in the software or the resistor. As in the
    value you put in might be slightly off so that it would turn slowly to one
    direction.

    Latez
    Seth
  • ArchiverArchiver Posts: 46,084
    edited 2000-05-21 20:33
    I'm afraid I can't help you much with the first problem, that would be my
    diagnosis as well. As far as the second problem, however, I encountered
    similar difficulty. It sounds like you're powering the servo and stamp off
    separate power supplies, a good idea, but it won't work unless you short
    both grounds together. I think that's your problem. Another possibility is
    that your "value" is not an appropriate number. Try outputting a 1.5 ms
    pulse. What type of BS are you using, because the timing values on each are
    different. As far as slow movement, I think that's because in each "for"
    statement, you're using X as the increment variable. Counting from 0 to 30
    would makes it pause longer at each value. If instead, you programmed:

    start:
    for x = 1 to 5
    pulsout pin#, value#1
    pause 20
    return

    for x = 1 to 5
    pulsout pin#, value#2
    pause 20
    return

    goto start

    It would move back and forth faster. You can also mess with the pause
    statement. The other possibility I can think of is that the load on the
    servos is too great.
    Hope that helps.
    -Erik Granstedt

    Original Message
    From: Brian & Sandy McMillion [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ARvF1KYSJtlm4c7yYRPXTRHspouDqLDEbdXrtIYXyR-1Ti6yDVlui7-ro-E2fL_4IiCHftOD]brianmcm@w...[/url
    Sent: Saturday, May 20, 2000 3:34 PM
    To: Stamps Forum
    Subject: [noparse][[/noparse]basicstamps] 3-Questions


    I'm trying to control multiple servos from a BS2 and ran across three
    problems. The servos are the Hitec HS300BB.
    1. I was trying to use a voltage regulator to obtain 6+ volts from a 12volt
    source. I was using a LM317T with the appropriate resistors in the circuit,
    according to the package diagram. Connecting the circuit to a meter I read
    6.7 volts. Connecting that circuit to the servo reads 2.7 volts. For a
    novice is this an indication that the servo is drawing more amps than the
    regulator can handle? If so what would be a good way to achieve a 6 volt
    output? The intent is a mobile device running off of one 12 volt source.
    2.After giving up on the 6volt problem I went ahead and connected the servo
    to a 6 volt source and the signal pin to the BS2. I used a simple program
    to determine the Pulsout Factor to position the servo:
    For X = 1 to 30
    pulsout pin#, Value
    pause 20
    return
    When I ran the program no matter what Value I entered the servo would rotate
    in one direction to the extreme position, same direction.
    I tried a resistor in the signal line with no difference. Being an
    electrical novice what is happening?
    3. Finally I noticed that the servo moved very slowly, I checked the
    voltage and it read 6 volts, I tried different servos with the same results.
    Any help would be appreciated.
    Thanks a bunch.
    Brian


    __________________________________________________
    Do You Yahoo!?
    Talk to your friends online with Yahoo! Messenger.
    http://im.yahoo.com
  • ArchiverArchiver Posts: 46,084
    edited 2000-05-21 21:30
    Thanks for the help, I haven't tried connecting the grounds together. As
    for the values I tried eveything from 30 to 15000 without luck.
    Brian
    Original Message
    From: Erik Granstedt <erik00h2o@y...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, May 21, 2000 2:33 PM
    Subject: RE: [noparse][[/noparse]basicstamps] 3-Questions


    > I'm afraid I can't help you much with the first problem, that would be my
    > diagnosis as well. As far as the second problem, however, I encountered
    > similar difficulty. It sounds like you're powering the servo and stamp
    off
    > separate power supplies, a good idea, but it won't work unless you short
    > both grounds together. I think that's your problem. Another possibility
    is
    > that your "value" is not an appropriate number. Try outputting a 1.5 ms
    > pulse. What type of BS are you using, because the timing values on each
    are
    > different. As far as slow movement, I think that's because in each "for"
    > statement, you're using X as the increment variable. Counting from 0 to
    30
    > would makes it pause longer at each value. If instead, you programmed:
    >
    > start:
    > for x = 1 to 5
    > pulsout pin#, value#1
    > pause 20
    > return
    >
    > for x = 1 to 5
    > pulsout pin#, value#2
    > pause 20
    > return
    >
    > goto start
    >
    > It would move back and forth faster. You can also mess with the pause
    > statement. The other possibility I can think of is that the load on the
    > servos is too great.
    > Hope that helps.
    > -Erik Granstedt
    >
    >
    Original Message
    > From: Brian & Sandy McMillion [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ekJESEulVfb7N7IbPBuV-Rs2N7aMgcOlTFUkMefkt3pYdxRPD_lEK-VIxQw36aQqzBmPedAC]brianmcm@w...[/url
    > Sent: Saturday, May 20, 2000 3:34 PM
    > To: Stamps Forum
    > Subject: [noparse][[/noparse]basicstamps] 3-Questions
    >
    >
    > I'm trying to control multiple servos from a BS2 and ran across three
    > problems. The servos are the Hitec HS300BB.
    > 1. I was trying to use a voltage regulator to obtain 6+ volts from a
    12volt
    > source. I was using a LM317T with the appropriate resistors in the
    circuit,
    > according to the package diagram. Connecting the circuit to a meter I read
    > 6.7 volts. Connecting that circuit to the servo reads 2.7 volts. For a
    > novice is this an indication that the servo is drawing more amps than the
    > regulator can handle? If so what would be a good way to achieve a 6 volt
    > output? The intent is a mobile device running off of one 12 volt source.
    > 2.After giving up on the 6volt problem I went ahead and connected the
    servo
    > to a 6 volt source and the signal pin to the BS2. I used a simple program
    > to determine the Pulsout Factor to position the servo:
    > For X = 1 to 30
    > pulsout pin#, Value
    > pause 20
    > return
    > When I ran the program no matter what Value I entered the servo would
    rotate
    > in one direction to the extreme position, same direction.
    > I tried a resistor in the signal line with no difference. Being an
    > electrical novice what is happening?
    > 3. Finally I noticed that the servo moved very slowly, I checked the
    > voltage and it read 6 volts, I tried different servos with the same
    results.
    > Any help would be appreciated.
    > Thanks a bunch.
    > Brian
    >
    >
    > __________________________________________________
    > Do You Yahoo!?
    > Talk to your friends online with Yahoo! Messenger.
    > http://im.yahoo.com
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-05-21 21:57
    The grounds HAVE to be together. I WILL !!NOT!! work right without it. I've
    had many problems fixed with this simple solution.
    -William


    Original Message
    From: Brian & Sandy McMillion <brianmcm@w...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, May 21, 2000 4:30 PM
    Subject: Re: [noparse][[/noparse]basicstamps] 3-Questions


    > Thanks for the help, I haven't tried connecting the grounds together. As
    > for the values I tried eveything from 30 to 15000 without luck.
    > Brian
    >
    Original Message
    > From: Erik Granstedt <erik00h2o@y...>
    > To: <basicstamps@egroups.com>
    > Sent: Sunday, May 21, 2000 2:33 PM
    > Subject: RE: [noparse][[/noparse]basicstamps] 3-Questions
    >
    >
    > > I'm afraid I can't help you much with the first problem, that would be
    my
    > > diagnosis as well. As far as the second problem, however, I encountered
    > > similar difficulty. It sounds like you're powering the servo and stamp
    > off
    > > separate power supplies, a good idea, but it won't work unless you short
    > > both grounds together. I think that's your problem. Another
    possibility
    > is
    > > that your "value" is not an appropriate number. Try outputting a 1.5 ms
    > > pulse. What type of BS are you using, because the timing values on each
    > are
    > > different. As far as slow movement, I think that's because in each
    "for"
    > > statement, you're using X as the increment variable. Counting from 0 to
    > 30
    > > would makes it pause longer at each value. If instead, you programmed:
    > >
    > > start:
    > > for x = 1 to 5
    > > pulsout pin#, value#1
    > > pause 20
    > > return
    > >
    > > for x = 1 to 5
    > > pulsout pin#, value#2
    > > pause 20
    > > return
    > >
    > > goto start
    > >
    > > It would move back and forth faster. You can also mess with the pause
    > > statement. The other possibility I can think of is that the load on the
    > > servos is too great.
    > > Hope that helps.
    > > -Erik Granstedt
    > >
    > >
    Original Message
    > > From: Brian & Sandy McMillion [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=5VU52RttwUUG0KijpKwVjXvasiY9RO2gPMnv3h_710z4Xzmbdr4cVDcFZH_oyDeh6-GzCy_dbg]brianmcm@w...[/url
    > > Sent: Saturday, May 20, 2000 3:34 PM
    > > To: Stamps Forum
    > > Subject: [noparse][[/noparse]basicstamps] 3-Questions
    > >
    > >
    > > I'm trying to control multiple servos from a BS2 and ran across three
    > > problems. The servos are the Hitec HS300BB.
    > > 1. I was trying to use a voltage regulator to obtain 6+ volts from a
    > 12volt
    > > source. I was using a LM317T with the appropriate resistors in the
    > circuit,
    > > according to the package diagram. Connecting the circuit to a meter I
    read
    > > 6.7 volts. Connecting that circuit to the servo reads 2.7 volts. For a
    > > novice is this an indication that the servo is drawing more amps than
    the
    > > regulator can handle? If so what would be a good way to achieve a 6
    volt
    > > output? The intent is a mobile device running off of one 12 volt source.
    > > 2.After giving up on the 6volt problem I went ahead and connected the
    > servo
    > > to a 6 volt source and the signal pin to the BS2. I used a simple
    program
    > > to determine the Pulsout Factor to position the servo:
    > > For X = 1 to 30
    > > pulsout pin#, Value
    > > pause 20
    > > return
    > > When I ran the program no matter what Value I entered the servo would
    > rotate
    > > in one direction to the extreme position, same direction.
    > > I tried a resistor in the signal line with no difference. Being an
    > > electrical novice what is happening?
    > > 3. Finally I noticed that the servo moved very slowly, I checked the
    > > voltage and it read 6 volts, I tried different servos with the same
    > results.
    > > Any help would be appreciated.
    > > Thanks a bunch.
    > > Brian
    > >
    > >
    > > __________________________________________________
    > > Do You Yahoo!?
    > > Talk to your friends online with Yahoo! Messenger.
    > > http://im.yahoo.com
    > >
    > >
    > >
    >
    >
    >
    >
Sign In or Register to comment.