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Can the Stamp 1 control two CR servos? — Parallax Forums

Can the Stamp 1 control two CR servos?

Hello!
Adafruit sells this thing Mini 3-Layer Round Robot Chassis Kit - 2WD with DC Motors](https://www.adafruit.com/product/3244) which is normally controlled by an appropriately installed Arduino type. and a motor shield, also a motor hat for the PI. I'm convinced that it can be better driven by the two CR servos that the BOE uses, and of course a single Stamp 1. Now if the Stamp 1 doesn't have the ability to properly manage the two servos, then I'll opt for the Stamp2, and balanced on a BOE.
Four Mascots out, and Sergei Rachmaninoff Piano Concerto No. 3 in D Minor, Op. 30 on the smart speaker because it's the composers 150th b-day. https://wqxr.org/

Comments

  • You can do it, but you have to ensure that you refresh the servos appropriately. The BS2 is faster, has more memory, and better resolution for PULSOUT (2us vs 10us), but from a software point of view, it has no real advantage of the BS1. Upgrade to a P1 and you have all kinds of options without having to jump through hoops to refresh the servos properly.

  • @JonnyMac said:
    You can do it, but you have to ensure that you refresh the servos appropriately. The BS2 is faster, has more memory, and better resolution for PULSOUT (2us vs 10us), but from a software point of view, it has no real advantage of the BS1. Upgrade to a P1 and you have all kinds of options without having to jump through hoops to refresh the servos properly.

    Hello!
    And thank you Jon for your well received advice. Be aware that you've also won the prize for being the first one to respond to this idea.

  • It's pretty small - notice that those yellow TT motors just fit into the space. Might want to measure the servos you have and see if they'll fit.

  • @"Jeff Haas" said:
    It's pretty small - notice that those yellow TT motors just fit into the space. Might want to measure the servos you have and see if they'll fit.

    Hello!
    I did, and am I'm not exactly sure of the CR servo idea. The firm sells two kits, sadly #2 was the one that Micro Center is working to run down. Ironically the same motors were included as part of a motorized something kit, back when Radio Shack (!) was shutting itself down as a full service store.

    However, what's the story about the frustrated mountain lion examining the garbage cans in the vicinity of a random member's place?
    Mascots abounding.

  • Hello!
    I did some thinking about this, overnight. And also after food. Those TT motors were always chosen because of size and such like. The end result is to use for the Pi a motor driver hat. And for the Arduino and things programmed the same way, motor driver shields. I think I have in stock an H-Bridge motor driver, perhaps two. Would those work with the Stamp for doing so? Or has this become a thought experiment that ran itself into a wall?

    Multiple mascots.

  • JonnyMacJonnyMac Posts: 8,963
    edited 2023-04-03 17:16

    Without set-and-forget, fixed-frequency, variable duty cycle PWM on the Stamp, I (speaking only for myself) would not attempt motor control with any of the Stamps. That said, Scott Edwards wrote an app note on controlling the speed of a small DC train using the BS1.

    Found the PDF. It's attached. page 101.

  • If you're going to use the CR servos you already have, it probably makes sense to build a robot platform to suit them. Do you have Gordon McComb's "Robot Builder's Bonanza"? Lots of excellent advice in there on making your own inexpensive robots.

    Or if you have the yellow TT motors then get one of these Erco-approved motor drivers:
    https://components101.com/modules/mx1508-dc-motor-driver-pinout-features-datasheet

    They're cheap and work really well. The BS1 can do PWM so you can vary the speed of the motors.

  • @"Jeff Haas" said:
    If you're going to use the CR servos you already have, it probably makes sense to build a robot platform to suit them. Do you have Gordon McComb's "Robot Builder's Bonanza"? Lots of excellent advice in there on making your own inexpensive robots.

    Or if you have the yellow TT motors then get one of these Erco-approved motor drivers:
    https://components101.com/modules/mx1508-dc-motor-driver-pinout-features-datasheet

    They're cheap and work really well. The BS1 can do PWM so you can vary the speed of the motors.

    Hello!
    Yes I do have his book. Well one edition of it. As for that gizmo, I believe I have one or two, or more. I'll need to check.

  • @"Jeff Haas" and @JonnyMac
    I've decided to temporarily shelve the project, since I now realize I'm a little over my head with all of that.

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