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About to begin robotics

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  • mhobbiesmhobbies Posts: 4
    edited 2014-05-29 05:39
    Robot Building for Beginners is a good starting point.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-05-29 06:02
    yeah, i do appreciate that but could you suggest a motoer driver for it, or what motor driver does the scribbler use ?
  • Martin_HMartin_H Posts: 4,050
    edited 2014-05-29 06:30
    The motors on your second kit can be controlled by almost any H-bridge or a serial motor controller. The sn75441 motor driver is a popular one because it requires a minimum of external components, both Duane and I use it frequently in various projects. If you use it, you should learn about using PWM to control the speed of the motors via the enable line. A serial motor controller bundles an H-bridge with another MCU to allow for a control to set the speed without worrying about PWM. The Parallax HB-25 http://www.parallax.com/product/29144 is one, but is used for larger motors than your application.

    Note: one reason continuous rotation servos are used on so many small robots is that they include their own motor control logic which makes using them so easy. I love them and use them frequently.
  • Duane DegnDuane Degn Posts: 10,498
    edited 2014-05-29 08:11
    Martin_H wrote: »
    The sn75441 motor driver is a popular one because it requires a minimum of external components, both Duane and I use it frequently in various projects.

    I second Martin's suggestion. Either that or Martin is seconding my suggestion.

    There are lots of inexpensive L298 boards on ebay. People I consider to be robot experts (Gordon McComb and Russell Cameron) don't like them but I use them on both my Rover 5 robots.

    I haven't used it a lot, but so far I like the MC33926 controller but it's designed for larger motors.
  • ercoerco Posts: 20,032
    edited 2014-05-29 09:03
    whiteoxe wrote: »
    can you direct me to a motor controller on ebay for this new wheeled robot, i saw some for about 3 buycks each, but im locked out of ebay atg the moment, my password is not working and when i ask for a new resrest to be sent to my email or phone it doestent arrive, so i cant go and check out the one i bought, and seem to have lost. The motors on the one ive build are identical to the one in the scrippler. I will probably make it prop powered.

    Check your junk mail folder, that's where my Ebay password change email went.

    BTW, those may not be the same as the Scribbler gearmotors. They look similar, but the wheels shown in your photo suggest that they are paired with the same high speed, low torque motors that come with the Magician robot chassis. If so, they are too squirrely to use reliably from my experience. If you can turn the wheel easily by hand, that's a bad sign that the gear reduction ratio is too low.
  • Duane DegnDuane Degn Posts: 10,498
    edited 2014-05-29 09:16
    I just found these L9110S boards on ebay. I'm going to get a few to try.

    Over on Let's Make Robots, Bill Henning just asked about H-bridges. I looked for prices on the L9110S based on suggestions I saw there.
  • Martin_HMartin_H Posts: 4,050
    edited 2014-05-29 09:32
    Duane Degn wrote: »
    I second Martin's suggestion. Either that or Martin is seconding my suggestion.

    Well that's what I get for not reading earlier posts.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2014-05-29 10:16
    You guys can't use those motor driver boards. Clearly says in the title it's for the Arduino. Sheesh. Don't you fellers know anything?
  • ercoerco Posts: 20,032
    edited 2014-05-29 10:39
    Duh... you just have to scratch "Arduino" off the board and you're all good to go.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-05-29 20:33
    erco wrote: »
    Duh... you just have to scratch "Arduino" off the board and you're all good to go.

    hee heee


    Ive done some cleaning up and now im looking hard for the ebay motor controllers and some edge detectors. Im always missing stuff till it turns up !!!
  • whiteoxewhiteoxe Posts: 794
    edited 2014-05-29 20:46
    what sensors would be needed to recognise a coloured ball and follow and bump ? ping and colour pal ?
  • Duane DegnDuane Degn Posts: 10,498
    edited 2014-05-29 21:08
    whiteoxe wrote: »
    what sensors would be needed to recognise a coloured ball and follow and bump ? ping and colour pal ?

    I'm pretty sure the ColorPal only works well with object which are very close to the sensor.

    To track a colored ball, the Pixy (aka CMUcam5) would probably be your easiest solution.
  • whiteoxewhiteoxe Posts: 794
    edited 2014-05-29 21:41
    Oh well, thanks anyway :)
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