Shop OBEX P1 Docs P2 Docs Learn Events
Robot Build-Fest — Parallax Forums

Robot Build-Fest

ercoerco Posts: 20,256
edited 2012-07-18 18:36 in Robotics
There's a flurry of late-night robot building at my house this week. Piecing together a new bot for ROBOT magazine, submission deadline looming Monday. I'm using the Dagu Magician chassis with CR servos instead of the undergeared motors it ships with. Prime building time for me is midnite to 3 am, working around the twins' sleep schedule, wife's birthday & gift-building this week, after-hours video conferences at work, and numerous other interruptions. I'm trying some brand new & cheap sensor stuff out, so I sure hope it works as intended. There's no time for errors. Since they say "sell the sizzle, not the steak", I started with a little bling shown below. More to come. (Big shoutout to Chris Savage for posting a Youtube comment long before I even posted here!)

Comments

  • ercoerco Posts: 20,256
    edited 2012-06-13 17:40
    In a marginally related story, here's the all-time worst TV special effects ever, from Knight Rider. The car shown going over the cliff is a white sedan, not a black Firebird!

    http://www.youtube.com/watch?v=dCY1pmBxg90&feature=player_detailpage#t=265s
  • ercoerco Posts: 20,256
    edited 2012-06-14 01:24
    Three touch sensors (in addition to just being three simple switches) make a virtual rotary dial for user input. My three cents worth! :)
  • ajwardajward Posts: 1,130
    edited 2012-06-16 22:03
    erco wrote: »
    In a marginally related story, here's the all-time worst TV special effects ever, from Knight Rider. The car shown going over the cliff is a white sedan, not a black Firebird!

    http://www.youtube.com/watch?v=dCY1pmBxg90&feature=player_detailpage#t=265s

    I like the scenes where a car is shown racing down the highway and somehow flips over. While sliding along, Upside down, you notice there is no engine or transmission. :-)

    @
  • Martin_HMartin_H Posts: 4,051
    edited 2012-06-17 06:56
    Erco, what technique are you using to measure capacitance? RC decay?
  • ercoerco Posts: 20,256
    edited 2012-06-17 10:02
    No sir, it's a built-in function in that no-name chip. :)
  • Martin_HMartin_H Posts: 4,051
    edited 2012-06-17 19:02
    erco wrote: »
    No sir, it's a built-in function in that no-name chip. :)

    How sensitive is this chip which can not be named? Can you do capacitance based proximity sensing or it it strictly contact?
  • ercoerco Posts: 20,256
    edited 2012-06-17 19:57
    Capacitive. No direct finger contact, insulation required. Just a pad of metal or a trace on a PCB.
  • ercoerco Posts: 20,256
    edited 2012-06-17 22:40
    My mobile, M2 multitasking, meandering Magician...
  • ercoerco Posts: 20,256
    edited 2012-06-18 01:41
    Late night touchpad fun!
  • Martin_HMartin_H Posts: 4,051
    edited 2012-06-18 06:25
    erco wrote: »
    Capacitive. No direct finger contact, insulation required. Just a pad of metal or a trace on a PCB.

    What I mean is does it have the range to be used as non contact bump sensors like the Theremin Vision http://thereminvision.com/ ?
  • ercoerco Posts: 20,256
    edited 2012-06-18 09:20
    No proximity sensing, you really have to touch it. Which is probably more useful for most applications. It really is magical, no components required, just a metal pad.
  • WhitWhit Posts: 4,191
    edited 2012-06-18 14:27
    Can't wait to see this article erco, old pal...
  • ercoerco Posts: 20,256
    edited 2012-06-18 15:26
    Whit wrote: »
    Can't wait to see this article erco, old pal...

    Thanks Whit! I can always count on you for a good word (as well as THE Good Word). So much better than hearing "why on earth would anyone want to build THAT?"
  • ajwardajward Posts: 1,130
    edited 2012-06-19 01:54
    erco wrote: »
    Thanks Whit! I can always count on you for a good word (as well as THE Good Word). So much better than hearing "why on earth would anyone want to build THAT?"

    If anyone has to ask that question, they simply don't understand! ;-)

    And... nice work Sir!!!

    Amanda
  • Martin_HMartin_H Posts: 4,051
    edited 2012-06-19 06:29
    Cool video erco.

    So what's the biggest use you have found for the multi-tasking aspects of this chip that shall not be named?

    With the BS2 I've found processing serial input while tending servos or motors tends to be the place where its single tasking limitations show up. But reading sensors and tending servos it seems have enough power. When you add a serial motor driver or Servo Pal that tends to solve a lot of problems.
  • ercoerco Posts: 20,256
    edited 2012-06-19 10:12
    Serial I/O is still a bottleneck on that chip. I'm thinking that encoder watching is a good robotic task to offload. My early bench test looked promising. http://www.youtube.com/watch?v=PfMnl4oGzs8
  • Martin_HMartin_H Posts: 4,051
    edited 2012-06-19 18:29
    On the Arduino you are not supposed to call serial I/O in an interrupt service routine. So its background tasks are somewhat limited as well. However they're supposed to work well for encoders.

    The propeller really is top notch for background processing, but I don't use it nearly to its full potential.
  • ercoerco Posts: 20,256
    edited 2012-07-11 09:13
    Two new videos. Using 3 touchpads to enter binary numbers: http://www.youtube.com/watch?v=DFvkh1Q7ZuQ

    And using the touchpads to enter a path, like ye olde Big Trak. Each press adds a fixed distance to travel or turn. Turns are not calibrated yet, but the bot is working nicely in this first test.

    Details in the next ROBOT magazine issue, due any day now. Small cover photo!
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-07-11 09:16
    Very nicely done!!

    You are truly an inspiration and a frustration at the same time!! A paradoxical Parallaxian!!
  • ercoerco Posts: 20,256
    edited 2012-07-11 09:36
    Yo Dawg, dats wat I doo...
  • ercoerco Posts: 20,256
    edited 2012-07-12 14:51
    ROBOT magazine has started to upload the online portion of the article. No code listings yet for some mysterious reason...

    http://find.botmag.com/091206
  • WhitWhit Posts: 4,191
    edited 2012-07-12 19:54
    Super cool! Looking for my magazine every day!
  • WhitWhit Posts: 4,191
    edited 2012-07-14 18:52
    erco's bot is nicely documented in this month's Robot Magazine. Got mine yesterday...

    It is a great article. Congrats again erco!

    Online features here - http://find.botmag.com/091206
  • ercoerco Posts: 20,256
    edited 2012-07-15 14:39
    No fair, I haven't even gotten mine yet!

    Thanks for the kind words, Whit. You're a good man!
  • ercoerco Posts: 20,256
    edited 2012-07-16 08:43
    Mary Had a Little 'Bot... http://www.youtube.com/watch?v=cB_xIlnZ_SU
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-07-16 09:04
    Well done article PLUS a nice little shot of the twins in the corner!!
  • ercoerco Posts: 20,256
    edited 2012-07-16 09:46
    Thanks Rick. The magazine editor likes people shots in the article, and the twins are a lot more photogenic than I could ever hope to be. :)

    I sure hope I get my copy today!
    smallhats.JPG
    900 x 564 - 80K
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-07-16 12:29
    You're right a photo of you in either of those outfits just wouldn't have the same....um....appeal. :lol:
  • ercoerco Posts: 20,256
    edited 2012-07-18 18:36
    Just got my magazine. SHEESH... back to back with Steve Norris' Super Arduino BoeBot, plus ANOTHER Steve Norris article with a plywood MadeUSA robot.

    If I may quote from my own article, "There is no shortage of complete differential drive robot kits to choose from..." No fact checking required outside of this same issue! Hey, at least my red robot made the cover. On a red background. :)
Sign In or Register to comment.