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Re: [Sumovore] 24 Hr's to CIRC & Sumovore is behaving bad

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  • GrantM.
    ... Well not *all* the torque, it s also highly dependant on what type of PWM mode you use. ... The basic stamp will do PWM but it chews up lots of clock
    Message 1 of 5 , Oct 8, 2004
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      At 07:34 AM 11/5/2004, you wrote:
      >It is 24 hrs until our first sumo competition and I'm thinking about
      >reversing nearly all of the changes I made to the sumovore my wife
      >and I want to compete with. It all started out nicely enough; my
      >wife likes to solder and wanted to build another bot kit. We got
      >the 'vore with the intent that she could compete with it. She
      >completed the kit with the analog controller and then I had an idea -
      >let's change out the motors! (fatal mistake #1)
      >
      >Well, we took it along with a black piece of plywood with medical
      >tape around its edges to a Central Illinois Robotics Club meeting
      >where some of the other guys had brought their min-sumos. Their jaws
      >dropped when they saw how fast her bot moved! If it lined up right,
      >it could push anyone. However, if it missed, it went flying off the
      >ring. "No problem", I said, "we can put one of the microcontroller
      >boards on it and use PWM to slow the motors down while keeping all
      >that torque."

      Well not *all* the torque, it's also highly dependant on what type of PWM
      mode you use.


      >This was several months ago when only the BS & AVR boards were
      >available. I hadn't used either controller yet, but We had a BS2 for
      >another project that we never did so I made fatal error #2 - I go the
      >BS2 board. Life got in the way of bots and my wife finally got the
      >board done last weekend. By that time, I learned that BS2 has no
      >hardware PWM & no interrupts so it was going to be difficult to slow
      >the motors down (I had also, by that time programmed an AVR for
      >another project and wished that I had chosen the other board).

      The basic stamp will do PWM but it chews up lots of clock cycles (not
      hardware driven as you said). Your right about the interrupts, the stamps
      have none. The Stamp daughterboard can however take any BS2 compatible some
      of them do support hardware PWM (like the basic atom for instance) last I
      checked there were 9 different BS2 compatibles.

      >Insert here all of the problems Tom Grey described - Brown outs,
      >unexplained sensor readings, code seeming to get stuck looping
      >through pars that were not even loops. Also insert the common
      >reasons - motor noise, loose connections (if the stamp is loose,
      >forward becomes turn right really fast), low batteries.

      How much current do these new motors draw?

      Regarding batteries, watch the brand. We have had good luck with alkaline
      duracell and energizer but stay far, far away from carbon cells the high
      internal resistance will cause resets.

      >I now have the power supply separated for the motor - original packs
      >for the electronics, 9V for the motor. I should do that the other
      >way around, but it would take longer to rewire. My problem now is
      >that the bot preforms significantly different when the motor power
      >begins to drop - which is after about 2 min of running - so I am
      >going batty trying to get the pauses right on the edge detect to keep
      >the bot from doing the hit me daisy dance along the edge of the ring.

      Running stock it was four continuous hours before there was any significant
      change in turn angle. Another company (http://www.nubotics.com/) is working
      on a wheel encoder for the GM8's (that the sumo uses). These could enable
      exact turning despite battery voltage. I was counting on the relatively
      flat discharge curve of batteries to give a consistent turn angle. I still
      use the same technique for my more advanced mini's.

      >I'm at work now, but I'm going home at noon to work on it some more
      >(between the list of errands my wife wants done today since we'll be
      >busy tomorrow). If I don't get it working good by around 9:00
      >tonight, I'm considering swapping the motors out for the lower power
      >ones and going back to the analog controller. ARRG!!!!!!!!!!

      You can always up the voltage a bit to the lower power motors, I have seen
      a few run up to 18V! they really zip around.

      >But, for some reason, I'm enjoying this!

      Glad to hear it :)

      GrantM.
    • paulpawelski
      It is 24 hrs until our first sumo competition and I m thinking about reversing nearly all of the changes I made to the sumovore my wife and I want to compete
      Message 2 of 5 , Nov 5, 2004
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        It is 24 hrs until our first sumo competition and I'm thinking about
        reversing nearly all of the changes I made to the sumovore my wife
        and I want to compete with. It all started out nicely enough; my
        wife likes to solder and wanted to build another bot kit. We got
        the 'vore with the intent that she could compete with it. She
        completed the kit with the analog controller and then I had an idea -
        let's change out the motors! (fatal mistake #1)

        Well, we took it along with a black piece of plywood with medical
        tape around its edges to a Central Illinois Robotics Club meeting
        where some of the other guys had brought their min-sumos. Their jaws
        dropped when they saw how fast her bot moved! If it lined up right,
        it could push anyone. However, if it missed, it went flying off the
        ring. "No problem", I said, "we can put one of the microcontroller
        boards on it and use PWM to slow the motors down while keeping all
        that torque."

        This was several months ago when only the BS & AVR boards were
        available. I hadn't used either controller yet, but We had a BS2 for
        another project that we never did so I made fatal error #2 - I go the
        BS2 board. Life got in the way of bots and my wife finally got the
        board done last weekend. By that time, I learned that BS2 has no
        hardware PWM & no interrupts so it was going to be difficult to slow
        the motors down (I had also, by that time programmed an AVR for
        another project and wished that I had chosen the other board).

        Insert here all of the problems Tom Grey described - Brown outs,
        unexplained sensor readings, code seeming to get stuck looping
        through pars that were not even loops. Also insert the common
        reasons - motor noise, loose connections (if the stamp is loose,
        forward becomes turn right really fast), low batteries.

        I now have the power supply separated for the motor - original packs
        for the electronics, 9V for the motor. I should do that the other
        way around, but it would take longer to rewire. My problem now is
        that the bot preforms significantly different when the motor power
        begins to drop - which is after about 2 min of running - so I am
        going batty trying to get the pauses right on the edge detect to keep
        the bot from doing the hit me daisy dance along the edge of the ring.

        I'm at work now, but I'm going home at noon to work on it some more
        (between the list of errands my wife wants done today since we'll be
        busy tomorrow). If I don't get it working good by around 9:00
        tonight, I'm considering swapping the motors out for the lower power
        ones and going back to the analog controller. ARRG!!!!!!!!!!

        But, for some reason, I'm enjoying this!

        Paul Pawelski
      • Tom Gray
        ... Good luck?! ... You have my sympathy! Ori Barbut posted a dual power supply that cured many of my problems; you should be able to find it. It uses the kit
        Message 3 of 5 , Nov 5, 2004
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          >
          > It is 24 hrs until our first sumo competition
          Good luck?!
          >
          > Insert here all of the problems Tom Gray described - Brown outs,
          > unexplained sensor readings, code seeming to get stuck looping
          > through parts that were not even loops. Also insert the common
          > reasons - motor noise, loose connections (if the stamp is loose,
          > forward becomes turn right really fast), low batteries.
          >
          You have my sympathy!

          Ori Barbut posted a dual power supply that cured many of my problems; you
          should be able to find it. It uses the kit AA packs for motors and a 9V
          battery for the BS2. I mounted a metal bracket on the scoop screws and
          turned both batteries on their side so their mass sits just behind the
          scoop, which gave good weight distribution. As for the sensor problem,
          Grant eventually tracked that to a loose resistor connection on the BS2
          brainboard. So it wouldn't hurt to resolder every dang connection on every
          board, even if they all look good!

          Hope you get it all nailed...

          Keep BEAMing and dreaming
          Tom
        • paulpawelski
          ... Well, I didn t get it all nailed, but I got it good enough that I didn t embarrass myself. I realized on Friday when I helped set up the venue that the
          Message 4 of 5 , Nov 7, 2004
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            --- In Sumovore@yahoogroups.com, "Tom Gray" <grayed@t...> wrote:

            > Hope you get it all nailed...

            Well, I didn't get it all nailed, but I got it good enough that I
            didn't embarrass myself. I realized on Friday when I helped set up
            the venue that the competition was going to be in the 30" ring, not
            the 5'. My practice ring at home is 4'. I became concerned that my
            edge detect response would back me out of the smaller ring if I
            tweaked it any more so I put off any additional changes.

            At the competition the next day, I beat my first opponent who also had
            a sumovore (analog brain, modified silicon tires). I won at least one
            game in each of the following two matches, but code problems did me
            in. In one game, my edge detect was too slow and the blade went over
            the edge and then stuck as it tried to back up.

            I ended up taking 3rd place. Second place was taken by the guy I beat
            in the first match. First place was taken by a custom bot that was
            much more advanced (no offense, just fact), but I at least I beat him
            once.

            If I run Ryo Ohkie (Rio Oh Key) again, I am going to use an AVR
            instead of a BS controller. After I went dual power supply and made
            sure all the pins were firmly in place, all the problems I encountered
            would have been easier to fix on a controller with hardware pwm and
            interrupt driven code. However, that will have to wait until I get my
            other project done, at highly expandable beginners robot for under $50
            (Cheryl & Dave , yup, this is the one that you were helping me price
            - thanks for the help).

            Paul
          • Tom Gray
            Way to go! I d say that was a pretty dang good record for a first competition! ... You beat him...and he s in first place? No shame there! At the NAIT
            Message 5 of 5 , Nov 8, 2004
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              Way to go! I'd say that was a pretty dang good record for a first
              competition!

              > Well, I didn't get it all nailed, but I got it good enough that I
              > didn't embarrass myself. I realized on Friday when I helped set up
              > the venue that the competition was going to be in the 30" ring, not
              > the 5'. My practice ring at home is 4'. I became concerned that my
              > edge detect response would back me out of the smaller ring if I
              > tweaked it any more so I put off any additional changes.
              >
              > At the competition the next day, I beat my first opponent who also had
              > a sumovore (analog brain, modified silicon tires). I won at least one
              > game in each of the following two matches, but code problems did me
              > in. In one game, my edge detect was too slow and the blade went over
              > the edge and then stuck as it tried to back up.
              >
              > I ended up taking 3rd place. Second place was taken by the guy I beat
              > in the first match. First place was taken by a custom bot that was
              > much more advanced (no offense, just fact), but I at least I beat him
              > once.

              You beat him...and he's in first place? No shame there!

              At the NAIT Challenge last month, my bot was one of three of robots tied for
              third. So they decided to have a play off. My Beta beat S3E3, who beat
              "Sumovore", who beat Beta. No clear winner there! In the end, they put all
              three in the ring for a "last one standing" battle. Beta and SV ganged up
              on S3E3, then SV beat Beta fair and square. Most fun we'd had all day!

              Tom
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