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Communication between two servos? — Parallax Forums

Communication between two servos?

willthiswork89willthiswork89 Posts: 359
edited 2006-07-21 05:51 in BASIC Stamp
is it possible to communicate between two servos? i have a homework board and a boe bot and wanted to make a wired remote control or somthing.... im getting incredibly board and running out of ideas to do with my new toy boe-bot(a.k.a Harold) how is this possible and is there any other ideas some people might have to make some contraptions... i thought about taking apart an old model airplane and seeing if i can use the RF receiver from it or possible a zipzap?

Comments

  • HarborHarbor Posts: 73
    edited 2006-07-21 04:32
    The web is full of things to attempt with robots in general and Boe-Bots in particular. Just a couple:

    1. Put a dowel on top of the Boe-Bot in freely rotating mount. Now see if you write the code to make the Bot move back and forth to balance the dowel. Like balancing a broom handle in your hand. One favorite way is to mount the dowel on a potentiometer with a horizontal shaft (parallel to the axle of the Bot). Then you can read out the position of the dowel with as a function of the pot reading. That isn't the only way though. Not by a long shot. Estimated time: one week to one decade. Depending on how good you insist on getting at the basic challenge.

    2. Hide and seek. Code the homework board to create a ruction of some sort in Bot detectable ways. Now put the homework board in one room, or even the corner of a room to start and let it begin calling. Program the Bot to find it, or at least get close enough to call "You're it!" If you have two Bots, they can take turns being it. This challenge has amazing complexities, even if the 'ruction' is a UHF transmission. Maybe especially then because it's not easily localized without a larger antenna than a Bot wants to haul around. Try using the two halves of a sonic rangefinder. Put the emitter on the homework board and try to find it using the sensor mounted on the Bot. IR sensors and emitters offer similar methods.

    3. Figure out how to make one servo slave itself to the movements of another servo. The basic answer to your question about their communicating is no. Not if you mean out of the box. But you can find ways to establish communication of sorts between two servos. It would take the fun out of it to tell you how of course...<g>
  • willthiswork89willthiswork89 Posts: 359
    edited 2006-07-21 04:37
    wow thats definantly a huge list there, ill definantly work on the dowel, the hide and seek will probably take a little more hardware considering i have the parts from WAM and The full boebot kit. but if i get the rangefinder and whatnot thats definantly a good idea, as for the communication i found that you can talk to one another using the SERIN and SEROUT i can transfer numbers through the wires.
  • HarborHarbor Posts: 73
    edited 2006-07-21 04:55
    Will said...
    as for the communication i found that you can talk to one another using the SERIN and SEROUT i can transfer numbers through the wires.
    Ah, but that's cheating. That's just two stamps talking to each other and issuing the same commands to their respective servos. The challenge is to have the first servo be one you aren't controlling. Either a computer someone else is programming, or a manually controlled lever. Now find a way to sense what's happening at that servo and cause the servo you control to do the same thing. (It's okay to have your Basic Stamp controlling that second servo. It's the first being out of your control that makes this a challenge worth considering.<g>) This is a slightly more elaborate challenge, but very similar to the problem of balancing a pole.

    [noparse][[/noparse]Uh... on consideration, let me be more careful of my wording. If you actually try to move a servo-controlled dowel, you may end up damaging the servo. For that version of the challenge, attach that dowel to a potentiometer. We have servos that will allow an outside force to move them and then report their position, but those aren't hobby-class servos. At least, I don't think they're available at hobby prices. This business keeps surprising me.<g>]
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  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2006-07-21 05:51
    willthiswork89,

    Here is a link that might be of interest to you. It uses the Propeller, but in practice
    the concept could be accomplished with any of the Parallax micro controllers.


    Parallax Forums > Public Forums > Propeller chip > Propeller Application: Proportional feedback from a Standard Hobby Servo (Updated video clip)

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
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