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Thread: Problems using PyPose with the Turtlebot Arm

  1. Problems using PyPose with the Turtlebot Arm

    Hello! I am trying to use the program PyPose to control the turtlebot arm but I am running into a series of weird errors as I use it. I understand that these errors are probably all interrelated, but I have yet to be able to fix any of them. I have the computer plugged into the ArbotiX board via a USB - Serial TTL cable, and the board is then wired into the arm correctly as per the tutorial instructions.

    1) When I run PyPose and try to capture a pose, it says it cannot read any of the 5 servos, but when I move the sliders and hit "set" the arm moves in a fast and jerky manner to a relatively random position. It does not slow down if I increase the delta-T, and the position it moves to is only slightly related to the position of the sliders. Also, all the servos move during the motion, even if only one of the sliders was changed. Does anyone know why this might be happening? I am happy to provide more information, but do not know what else would be useful!


    2) I am trying to compile the pypose.pde sketch, but I am getting the following error:


    Code:
    In file included from /usr/lib/gcc/avr/4.5.3/../../../avr/include/util/delay.h:44:0,
                         from /usr/lib/gcc/avr/4.5.3/../../../avr/include/avr/delay.h:37,
                         from /home/marc/sketchbook/hardware/arbotix/cores/arbotix/wiring_private.h:30,
                         from /home/marc/sketchbook/hardware/arbotix/cores/arbotix/WInterrupts.c:33:
        /usr/lib/gcc/avr/4.5.3/../../../avr/include/math.h:426:15: error: expected identifier or ‘(’ before ‘double’
        /usr/lib/gcc/avr/4.5.3/../../../avr/include/math.h:426:15: error: expected ‘)’ before ‘>=’ token
    The specific part of the math.h file in question is:


    Code:
    /**
            The round() function rounds \a __x to the nearest integer, but rounds
            halfway cases away from zero (instead of to the nearest even integer).
            Overflow is impossible.
        
            \return The rounded value. If \a __x is an integral or infinite, \a
            __x itself is returned. If \a __x is \c NaN, then \c NaN is returned.
         */
        extern double round (double __x) __ATTR_CONST__;  /** Line 426 */
        #define roundf    round        /**< The alias for round().    */

    All of my settings in the Arduino environment are correct (board type, serial port). Do you have any idea how to fix this error? I never modified the math.h file after downloading it (other than the comment indicating which line was 426 for this post). Thank you very much!


    I have also tried uploading the program directly using a terminal command:


    Code:
    sudo avrdude -p m644p -P /dev/ttyUSB0 -F -c dasa -U flash:w:pypose.pde

    Which I put together from reading various forums. It produces the following message:


    Code:
    avrdude: AVR device not responding
        avrdude: initialization failed, rc=-1
        avrdude: AVR device initialized and ready to accept instructions
        avrdude: Device signature = 0x000000
        avrdude: Yikes!  Invalid device signature.
        avrdude: Expected signature for ATMEGA644P is 1E 96 0A
        avrdude: NOTE: FLASH memory has been specified, an erase cycle will be performed
                 To disable this feature, specify the -D option.
        
        avrdude done.  Thank you.
    The board reacts as if something has happened, but the arm still behaves the same way as it did before. Can someone please give me some feedback on this? Does the command I am using look correct? Why would my board be giving an invalid device signature? Thank you very much!

    3) I am using the direct USB to Serial FTDI cable right now instead of the breakout board the Willow Garage recommended because the new version of the board is shorter than the one they were using and hits a piece of circuitry on the ArbotiX board, thus making it impossible to seat properly on the board. it is not something I could (or would want to) try to wedge into place. Does anyone have any ideas on how to connect the pins on the ArbotiX board to the socket on the breakout board (preferably via flexible wires) so that I can plug in the breakout board? The parts that I am trying to fit together are:

    http://www.trossenrobotics.com/p/FTD...eakout-5V.aspx (The image is old... the new one is more compact which is why I had problems, I assumed I was getting this one when I bought it)
    http://www.trossenrobotics.com/p/arbotix-robot-controller.aspx

    T
    hank you very much!

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    Re: Problems using PyPose with the Turtlebot Arm

    Quote Originally Posted by Aroarus View Post
    1) When I run PyPose and try to capture a pose, it says it cannot read any of the 5 servos, but when I move the sliders and hit "set" the arm moves in a fast and jerky manner to a relatively random position. It does not slow down if I increase the delta-T, and the position it moves to is only slightly related to the position of the sliders. Also, all the servos move during the motion, even if only one of the sliders was changed. Does anyone know why this might be happening? I am happy to provide more information, but do not know what else would be useful!
    If you can't read the current position, then the interpolation will fail (as the starting spot will always be wrong). Have you set the IDs of the servos properly?

    Quote Originally Posted by Aroarus View Post
    Code:
    sudo avrdude -p m644p -P /dev/ttyUSB0 -F -c dasa -U flash:w:pypose.pde
    PyPose.pde is an Arduino sketch, not a compiled firmware image -- this just won't work.

    Quote Originally Posted by Aroarus View Post
    3) I am using the direct USB to Serial FTDI cable right now instead of the breakout board the Willow Garage recommended because the new version of the board is shorter than the one they were using and hits a piece of circuitry on the ArbotiX board, thus making it impossible to seat properly on the board. it is not something I could (or would want to) try to wedge into place. Does anyone have any ideas on how to connect the pins on the ArbotiX board to the socket on the breakout board (preferably via flexible wires) so that I can plug in the breakout board? The parts that I am trying to fit together are
    This is the only style of breakout board available -- and it is exactly what we used on the TurtleBot arms here at Willow. It rubs up against the voltage select jumper, but that actually isn't a problem (in fact, it helps to keep the breakout board attached, since the headers used by SparkFun are a little on the loose side).

    -Fergs

  3. Re: Problems using PyPose with the Turtlebot Arm

    Thank you very much! Those answers were very helpful. I did manage to force the board into place without causing any apparent damage. As for the sketch, I managed to fix my error (with your help from another thread) and got it compiled and uploaded properly. Again, thank you. I am still not able to read the servos properly, but I am working through that. I greatly appreciate all of the help you have provided.

  4. Re: Problems using PyPose with the Turtlebot Arm

    Hi there,
    Were you ever able to see your servo id's and get them working?
    I am having the exact same problem as you are and have posted another thread on this topic as well.
    -Scott

  5. Re: Problems using PyPose with the Turtlebot Arm

    Yes I was able to get it to work by attempting to download the pypose sketch to the Arbotix repeatedly from the Arduino IDE. It eventually worked, and everything went smoothly after that. I literally had to hit the download button repeatedly for about 10 minutes. This was not optimal for me, as I still do not know why it didn't work before, but it did solve the problem. I hope this helps. I would be happy to talk more if that does not work for you.

  6. Re: Problems using PyPose with the Turtlebot Arm

    Thanks, I will give it a try and let you know what happens as I am still stuck as well. Much appreciated.

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