Let's Make Robots!

Mr. Spinny (with new pix)

 
persistence of vision

 
A persistence-of-vision robot.
 
Small 'bot built into a CD case (photo with cover off). It roams around, searching for a black tape line (kinda like a line-follower). However, when it find the line it spins *very* fast and the 7 leds are used to show POV text. The black line is used as a "marker" while spinning to sync the beginning of the text line so that it doesn't drift (even as the batteries wear down). The same single line sensor is used for detecting table-top edge so it doesn't fall off.
 
Two IR emitters and a detector are used for basic obstacle avoidance and for inter-bot fleet communication. A CDS cell is used for setting LED brightness (or for not doing POV at all if the room is just too bright). When not doing POV, the 'bot shows nice little patterns on the row of LEDs. It looks quite cool when "under glass" with the CD case cover on.
 
A single SX micro is used for the controller, along with an L293 dual H-bridge for the motor driver. Motors are Solarbotics GM8s but modified with the faster DC motors that Solarbotics sells to use for their GM8/2 gearboxes. The original motors in the GM8 weren't fast enough to get the persistence of vision going reliably. I should add that the faster motors are *reallllllllllllly* fast -- in the first test with the modified motors, the 'bot shot off the side of the table a full five feet into the air before falling.... it's also true what Solarbotics say -- these motors drain batteries quite quickly. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
Here's the schematic...
 
 
 
Lastly, a full-size PDF that may be used for mechanical/drilling template is here:
 
 
Get full source code (SX/B 2.xx beta and compiled assembly) at the link below. Note that even my SX/B code is almost all assembly anyway (most of my apps end up assembly by the end so they are compact and efficient).
 
 

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I like the CD spindle body. Video needed :)

I'll get video and more pix sometime in the next few weeks. I'm pretty busy and have a dorkbot meeting coming up, so things are tight.

 

P.S. -- I'll be eternally grateful if someone can tell me if using Safari on these pages is a waste -- it seems like nothing works quite right: text-to-links, extra image uploads, link insert thingy, etc.  

we wanna go elliptic! give video please!

It looks better w/cover on, actually. I'll update page later this month when I find time.

 Added link to full source code in main entry at top of page.

I like the look of that board, did you just spray paint it black or something?

Yeah, they're painted. For some reason, I *always* get asked about the black boards :-)

I use the cheapest flat black enamel spraypaint from the hardware store. On most of my projects the last few years, if the proto board will be visible when the project is finished, I paint the component side after any drilling and cutting.

a combo of a line follower and a POV display?

brillant :)

schematics are not clear, too smal pic :( please upload larger image

4 stars... only beacuse video is missing

 

More like a line "finder" (but of course it has to avoid other 'bots that are line-followers per se). There is a large version of schem. -- it's linked to below the inserted image.
Great where's the video?  NM - I was raised there ... go figure .. small world.
A very nice job too. But I concure with the others, this project just begs for a video if one ever did.