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operation speed of uVGA / Picaso

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  • operation speed of uVGA / Picaso

    For my current project I am plotting the position of stepper motor
    in real time on a VGA monitor, it typically takes about 2 millisecond
    for a single step pulse on generic stepper drivers

    however plotting the point gfx_line, two solid rectangle for clearing the
    previous X,Y values and then two putstr and a couple of additional str_getW and strCopy to strip out info from com buffer and two function calls to do the above, all this take about 4 millisecs

    this causes the stepper controllers to get a max speed of about (1000/(4+2) millsec) 166 pulse per sec and without the drawing it
    would be about 500 (1000/2) pulse per sec

    If it were possible to complete the drawing within 2 millisec then the mcu could pump out drawing commands while waiting to turn off the pulse to the stepper controller and we could achieve higher through put.

    Is there any plans to increase clock speed of Picaso?
    I think that it has a 12Meg crystal, is that correct?
    Any strategy to achieve quick screen updates small regions only?
    Ofcourse i could chop off another millisec from my fat lazy code, but i would be still left with about three millisec

  • #2

    One idea would be to start skipping every second, then every third etc drawing

    once you pass a certain speed.

    Picaso is pretty well flat out as it is, the main bottlneck of course is the display functions - fairly intensive work writing all those pixels


    • #3

      yup, thats what i am think about right now..
      what about over clocking picaso? is that even possible..


      • #4

        Picaso is already going at its 'maximum reliable' speed