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For Duane Degn, Private Instigator — Parallax Forums

For Duane Degn, Private Instigator

ercoerco Posts: 20,255
edited 2013-08-26 16:22 in Robotics
Looks like you and me got the Arduino boys riled up, Pal! :)

But they need 2 pins and a 4017 to control 8 servos. I had a bs2 driving 16, but IIRC you had 32 off a single Prop pin?

Comments

  • PublisonPublison Posts: 12,366
    edited 2013-08-25 08:35
    In Duane's 32 servo demo, he used 1 pin per servo.

    Parallax did use the 4017 method on the Propeller Control Board (#28205). Schematic in the spin file attached.
  • mindrobotsmindrobots Posts: 6,506
    edited 2013-08-25 09:51
    Video title says 10. I only counted 8.....maybe that Arduino is octal??? :smile:
  • PublisonPublison Posts: 12,366
    edited 2013-08-25 10:04
    I noticed that also.

    The 4017 only has 8 output pins.

    Oops The 724017 has 10 outputs. The parallax board only uses 8.

    But...I seriously doubt that most Arduino user know what octal is. :)
  • ercoerco Posts: 20,255
    edited 2013-08-25 11:34
    Publison wrote: »
    But...I seriously doubt that most Arduino user know what octal is. :)

    Them's fighting words! From a moderator! That makes you my new bestest friend, Pub! :)

    OK, I sit corrected. But I coulda sworn my hero Duane (at one point) claimed he could rule the world (or at least a pile of servos) with just one Prop pin.

    Was my hero worship misplaced?
  • PublisonPublison Posts: 12,366
    edited 2013-08-25 11:40
    erco wrote: »
    OK, I sit corrected. But I coulda sworn my hero Duane (at one point) claimed he could rule the world (or at least a pile of servos) with just one Prop pin.

    Was my hero worship misplaced?

    Must have missed that statement. Duane?
  • PublisonPublison Posts: 12,366
    edited 2013-08-25 11:44
    erco wrote: »
    Them's fighting words! From a moderator! That makes you my new bestest friend, Pub! :)

    In my defense, I don't think octal has been used on many platforms for years. (I'll probably get get flamed for that :) )

    Last time I used it was on my Altair 8800..
  • ercoerco Posts: 20,255
    edited 2013-08-25 12:14
    Publison wrote: »
    Last time I used [octal] was on my Altair 8800..

    Which also makes you my new bestest friend, since I inherited my Dad's IMSAI 8080, minus the front panel.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2013-08-25 13:21
    erco wrote: »
    . . . I coulda sworn my hero Duane (at one point) claimed he could rule the world (or at least a pile of servos) with just one Prop pin.

    I don't recall making the statement. I think ruling the world will require multiple pins.

    And, as Publison stated, I used one Prop I/O pin per servo in my 32 servo demo.

    Beau posted information about using additional chips to drive up to 144 servos with a single Propeller. Even with my compulsive servo hoarding over the last few years, I don't think I have 144 servos yet.

    erco wrote: »
    Was my hero worship misplaced?

    Hey, hey, just because I used more than one pin to control the servos is no reason to give up the worshipping. Besides, once my plans for world domination are carried out you can tell people you were doing it before it was cool (and manditory).
  • PublisonPublison Posts: 12,366
    edited 2013-08-25 17:04
    erco wrote: »
    Which also makes you my new bestest friend, since I inherited my Dad's IMSAI 8080, minus the front panel.

    Shall we play a game?
  • ercoerco Posts: 20,255
    edited 2013-08-25 20:42
    OK, so I made a few misteaks in starting this thread. The 2010 Arduino video predates mine and Duane's. Maybe we're the copycats!
  • kwinnkwinn Posts: 8,697
    edited 2013-08-26 08:13
    True. Once the length of a byte settled on 8 bits octal pretty much faded away.
  • PublisonPublison Posts: 12,366
    edited 2013-08-26 09:26
    Why do programmers always confuse Halloween and Christmas?
    Because 31 Oct = 25 Dec
  • ercoerco Posts: 20,255
    edited 2013-08-26 09:54
    Publison wrote: »
    Why do programmers always confuse Halloween and Christmas?
    Because 31 Oct = 25 Dec

    Now DAT's even funnier than "Hey Hamlet, 2B OR NOT 2B = $FF" :)
  • Beau SchwabeBeau Schwabe Posts: 6,558
    edited 2013-08-26 10:21
    erco,

    I wouldn't say all is lost.... using the 4017 to drive servo's is not a new idea.... here is something I posted in 2007 to decode the VEX servo pulse train, using a 4017

    http://forums.parallax.com/showthread.php/94784-Using-PULSIN-to-decode-VEX-rcvr-pulse-train?p=684341&viewfull=1#post684341

    BTW) I was simulating the VEX pulse train with a Propeller, so technically we were using only 1 pin to drive 8 servo channels in 2007 :smile:
  • ercoerco Posts: 20,255
    edited 2013-08-26 16:22
    XLNT.

    I guess it was one COG I was recalling, not one pin.

    BTW, It's not obvious in the Arduino video if the fast-moving servos are moving in controlled (incremented) fashion with speed control, or if they are simply being slammed from position A to position B at whatever speed they can muster.

    I found that I could cheat like that in my 4-flag-8-servo project. It was convenient to power everything from a single Li-Ion cell, which in itself slowed down the servos and made it look like I was doing some intentional servo speed control. Informed minds should know better.
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