servo control question

ReinerReiner Posts: 2
edited 2004-11-06 - 13:07:40 in Robotics
Hi everybody! I have just signed in, and am new to robotics.
Can you help me with a very basic question?
I need to control a smal number of servos (4 to 6) that will move in a certain programmed sequence once the "start" button is activated. This must happen with no connection to my computer.
Can u suggest wich items are needed for this?I would guess a stamp, a board for the stamp, a servo controller, batteries, a software for programming the board, servos, cables, etc...
I have never built anything robotic, and the list of available products made me dizzy. Some help pinpointing the actual parts i need would be very appreciated, thanks!!
Reiner

Comments

  • rounderrounder Posts: 18
    edited 2004-11-03 - 14:11:40
    A good place to start would be the "What's a microcontroller" kit. It introduces you to the basic stamp and includes a servo to get you started on your servo control project. Radio Shack sells it in their stores (catalog number 276-0625)

    As far as the specifics of your question. You will need a basic stamp, some type of carrier board for the stamp, a serial cable to program your stamp, servos, and batteries. If your project is just for demonstration purposes or does not require a high degree of accuracy you do not need to use a servo controller. The basic stamp can control servos directly using the pulseout command just fine. That being said, if you intend to continue to use the stamp for servo control in other projects then the parallax serial servo controller would be a wise choice. I hope this gets you started, if you have any other questions post em!

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  • allanlane5allanlane5 Posts: 3,815
    edited 2004-11-03 - 14:41:49
    If you are just starting out, I would recommend the BOE 'full-kit' (http://www.parallax.com/detail.asp?product_id=28102) for $120, or even better (because it comes with the What's A Microcontroller (WAM) class, with a servo) the BS2 Discovery Kit (http://www.parallax.com/detail.asp?product_id=27207 $169.00) -- make sure you add a 7.2 or 9-volt DC wall-wart power supply to the Discovery Kit, it does not come with.

    While this may seem pricey to someone starting out, this really is quite a reasonable price for what you get. The BS2 has revolutionized the world of micro-processor development by putting a PBasic module on a 24-pin wide DIP, then giving away the IDE with PBasic language. Plug in to your serial port (or USB port, but I prefer the serial version) start up the IDE, plug in the power to the BOE board, and you are good to go.

    For your purposes, once you've proven what you can do with the Servo in the WAM, you can buy some additional servo's to implement your project. The BOE board has Servo connectors on-card, and you can add additional servo connections with the prototyping bread-board on-card.

    The good news is for this $200.00 or less, you'll have everything you need, with lots of free downloadable documentation and the best support in the business.

    BTW, this may not be obvious, but once you've loaded your program into the BS2, your program sits in EEPROM on the module forever, waiting for power to be applied to run -- you need no further connection to your PC, until you want to load a new program. This is one of the really nice features of the BS2.
  • ReinerReiner Posts: 2
    edited 2004-11-04 - 10:04:46
    Thanks for taking the time to reply! I have in the meantime downloaded and read a lot of info.

    My specific need is to control a number of 4 to 6 servos in a creature, part of a magic show. Must be very reliable, and there are timed intervals between the actions. (creature rises, moves, goes back down... lurks motionless·for minutes, comes back up again, moves, goes down). timing must be precise as motion is in accordance to music sounds and effects. I guess the total time of the sequence would be about 5 minutes, perhaps a maximum of 7 (most of this time is just doing time waiting for action, action itself is limited to about 40 seconds, in two or three "appearances" of the puppet.

    I write this to inquire about the timing capabilities of the Stamp. Do you think it can handle the time requirements I·need?

    I was unable to find specific info about this aspect.

    Other than that, the whole thing is very interesting. I am a·backyard builder myself and can´t wait to get my hands on this. I made a string and spring version of the puppet, and it works, but i want to get my hands away from it, thus the project. Thanks for the help!!

    Rolf
  • BeanBean Posts: 8,076
    edited 2004-11-04 - 11:53:40
    Is the puppet going to be wireless or wired ?

    You could have a signal in the music that triggers the puppet.

    Record the music onto the LEFT channel of a tape/cd and record onto the RIGHT channel a tone whenever the puppet is suppose to do something.

    The RIGHT channel is not played to speakers, but instead goes to the puppet to signal it.

    If the puppet is wireless, then run the RIGHT channel signal to an infrared signal that is pointed at the puppet.

    Sounds like a very interesting project. Good luck.

    Bean.
  • dandreaedandreae Posts: 1,375
    edited 2004-11-06 - 13:07:40
    Hello,

    This project can be done very easily using the BS2 and the Parallax Servo Controller.· Here is a link for the PSC:

    http://www.parallax.com/detail.asp?product_id=28023

    Dave

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Dave Andreae

    Tech Support
    [url=mailto:dandreae@parallax.com]dandreae@parallax.com[/url]
    www.parallax.com

    ·
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