Comments on: TSP Guide

By: MakerBlock

MakerBlock — Thu, 15 Mar 2012 18:33:48 +0000

@SnyperBob: Awesome!!! I like using the portable apps version of Inkscape, so I might have missed out on the full Python install. 🙂

By: sandy

sandy — Wed, 14 Mar 2012 22:18:49 +0000

I’m not completely sure – the SPI interface is also exposed on the ICSP header on an arduino – that’s the little six-pin header towards the right-hand-side of the board, and it looks like the Ethernet shield relies on connecting using _those_ pins rather than 10-13. Which is why it’ll work ok on a MEGA too (the ICSP header is in the same place on both boards).

BUT I _think_ because the uno boards expose SPI on 10-13 as well, then when the adafruit motorshield uses those pins, it might fritz the SPI connection in both places. Can’t tell without testing it.

By: SnyperBob

SnyperBob — Wed, 14 Mar 2012 21:47:42 +0000

Makerblock, nice write up! These TSP drawings work great on Drawing Machines that don’t have a servo to lift the pen. That’s how I figured out to use TSP…..researching single line drawings, lol.

The only thing I did different from your write up, is I just installed Inkscape, and that gave me Python I believe

By: SnyperBob

SnyperBob — Wed, 14 Mar 2012 21:38:51 +0000

I would love to see a write up on the Mega+SD card version! I put in an order for a few Megas today. They’re coming from China, so I have some time 🙂

By: MakerBlock

MakerBlock — Wed, 14 Mar 2012 21:03:33 +0000

What do you think – would this help?
https://www.adafruit.com/products/201
http://makerblock.com/2012/03/speedier-drawbot-drawings/

By: sandy

sandy — Wed, 14 Mar 2012 11:39:59 +0000

Yep the mega is a sledgehammer to crack a nut, but it has two advantages: First, plenty memory for software developments + SD card reading library and second, SPI interface that the SD card reader needs is on pins 51, 52, 53 and 54 instead of 10, 11, 12 and 13. And that’s good because the motorshield uses 10-13 already.

They are so expensive though, for a proper one. Your cheaper clone boards will be ok though – 1280 is fine.

The SPI pins being different means that any “shield” type card readers won’t work, so I’ve been using little breakouts – the adafruit micro-sd breakout is pricey but does the job http://www.flickr.com/photos/euphy/6777735609 simple to wire up. I’m planning on making up a short run of super-polargraph machines based on the mega+sd card soon, so I will write up a guide before that, and instructions on how the software works on it.

Currently debating about whether I should to add a rudimentary hardware interface (buttons and lights) or just do everything through the software.

By: MakerBlock

MakerBlock — Tue, 13 Mar 2012 23:31:46 +0000

Hmm… Well, suppose the increase in speed is probably worth it. At three seconds a point… some of these drawings would take ages!
I think I’ll have to invest in an Arduino Mega 🙂
Keeping in mind I have very little expertise in hardware, would you be willing to do a tutorial for dummies on wiring up an SD card and Arduino Mega?

By: sandy

sandy — Tue, 13 Mar 2012 22:57:46 +0000

Don’t think so – it’s the length of time to get a new command from the controller. Mine isn’t quite 3 seconds, but not far off. The solution is to save your queue to an SD card and run from that instead! No pause at all! Huzzah for SD cards! Oh and arduino megas. And you can’t stop it once it’s started. It’s like an arty terminator.

By: MakerBlock

MakerBlock — Tue, 13 Mar 2012 22:48:53 +0000

Hey Sandy,
I noticed that drawing TSP/vectors is incredibly slow on my DrawBot. It pauses for about 3 seconds between each point. Is this normal? Is there any way to speed this up?
Thanks!
MakerBlock