Restarting a Stalled DrawBot Drawing

Over the last two days or so I’ve drawn the largest picture yet with my DrawBot.  I started it on Friday night and, with numerous pauses and other misadventures, finished it this morning.  The drawing is roughly 12″ x 18″ or so. 1  With no apparent rhyme or reason the drawing would pause numerous times.  I would estimate about 25 or so.  Also, the pen had a difficult time towards the end.  I believe this was in part due to the angle of the pen on the drawing surface and the quantity of the ink left.  As of this morning I was still using version 1.1.2, but I’m installing version 1.1.4 right now. 2

Here are some additional thoughts:

  • In an earlier post I had mentioned I was having stalling problems while drawing.  Sandy asked whether I was able to change serial ports to a different one and back again.  The answer is “sort of.”
  • When there’s a stall, here’s what I do:
    1. Click “SETUP->SERIAL PORT…
    2. Click on some other serial port other than the one I’ve been using
    3. Disconnect and then immediately reconnect the USB cable from the computer
    4. Click on the original serial port I had been using
    5. As soon as the Drawbot reestablishes a connection with the Polargraph controller software, it starts drawing right where it left off
  • I used to export a copy of the existing queue before doing all of this, and while it is still a very good idea, it doesn’t seem necessary.
  • This exact process has worked several times in a row without a problem.  Interestingly, step number 3 above3 is critical.  If I exclude this step the program crashes.
  • For this drawing I used a Pilot Precise Rolling Ball V5, extra fine tip, black.  I had used a red pen of the same make for a prior drawing and it worked reasonably well.
  • I’m in the process of designing a new pen gondola.  I think something that can angle the pen downwards would help the pen apply ink to the page.
  • Interestingly, I noticed after about 80% of the drawing was done the pen had a little bit of paper fuzz on it.  Once I removed this, the pen seemed to work a lot better.
  • The pen stopped drawing completely after about 85% of the drawing over all.  This was a bit disappointing.  However, since I was drawing from the top right to the bottom left and the version of the Polargraph controller I was using allows you to specify which area to start from, I just restarted the same drawing from the bottom right corner and ended up with a very satisfactory result.

In other words, it’s a nice day to start again.

  1. I rolled it up and gave it to a friend before I thought to take a photogram []
  2. One of Sandy’s latest posts suggests there’s a 1.1.5 available, but I couldn’t find it. []
  3. The disconnect and reconnection of the USB cable from the computer []

5 Responses to “Restarting a Stalled DrawBot Drawing”

  1. Sandy Noble says:

    Aha, the 1.1.4 that’s listed on the site (25th Feb) _is_ the 1.1.5 that I thought I was talking about. I was just being a spanner. Anyway, glad you sort of found a solution. I take it your board is powered by an external power supply (so not by USB), and that’s why you’re able to disconnect the usb without it resetting?

    It’s an odd one. It might be that the board itself stops transmitting it’s “READY” for one reason or another. Or it might be that the USB connection dies for some other reason. If you run the controller through the Processing environment rather than the standalone version, then you should be able to see what exactly is coming from the board in the console. It could be illuminating.

    Cheers!!
    sn

  2. MakerBlock says:

    @Sandy: I figured you were talking about the 1.1.4. :)
    My board is powered by the external power supply, rather than powering the motor shield separately.
    So, I’m not entirely sure which software to which you’re referring. I’ve only ever used the “polargraphcontroller” software and not the “polargraph_queue_runner” yet. What’s the difference between the two? Do I create the queue using the controller and then import the saved queue in to the queue runner?
    Basically, all I see is that the controller software reports the Arduino is still busy – even though it is sitting idle.

  3. Sandy Noble says:

    Yep I didn’t mean the queue runner, I just meant that if you download the source code for the controller, and install the libraries and run it through processing (rather than downloading the precompiled binaries), then you’d get more insight into what is actually going on, because all the messages coming from the board are echoed out to the console, and you get to see exceptions and things.

  4. MakerBlock says:

    @Sandy: Ooooooh! Well, I’ve never tried such a thing! I’ll give it a shot!

  5. […] using my DrawBot to draw pixelated drawings (versus TSP or vectors)1 I don’t really notice a pause from the machine between each […]

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