a quick question

Comments

• invad8er Posts: 14

  2009-05-27 01:02 edited 2009-05-27 01:02

  also the servos don't have the PCB
• Franklin Posts: 4,747

  2009-05-27 02:36 edited 2009-05-27 02:36

  Somebody said...
  also the servos don't have the PCB

  What is the model number of the "servo"?
  Servos don't work with H bridges, motors do.
  Could you use the attachment manager to attach the actual code that does not work.
  The code you included is not designed for an H bridge.
  
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  - Stephen
• invad8er Posts: 14

  2009-05-27 02:49 edited 2009-05-27 02:49

  technically there geared motors
  www.solarbotics.com/products/gm4/
  link to something like the motor
  
  
  i know the code is not ment for an H bridge
  
  i was asking how to modify the code to work with an H bridge
  that was the base code that i had started from
• sylvie369 Posts: 1,622

  2009-05-27 11:09 edited 2009-05-27 11:09

  I may be wrong, but I think you're doomed from the start here.
  
  H bridges are simply circuits that provide voltage across a motor or other load.
  Servos require pulses of different widths to set their positions (see all of those "PULSOUT" commands in the servo control code that you attached). An H bridge doesn't output pulses.
  
  What are you trying to accomplish? Are you simply wanting to learn about H bridges? Or are you replacing the continuous rotation servos with a pair of DC motors? If the latter, you should be able to drive them by connecting the H bridge outputs across the motor terminals, then setting the H bridge's enable pin high, and setting one of the inputs high should turn the motor one way, and setting the other one high should turn it the other way. Remember to set the bridge inputs low again after using them: if they're both high, nothing happens.
  
  Post Edited (sylvie369) : 5/27/2009 11:16:07 AM GMT
• invad8er Posts: 14

  2009-05-27 12:16 edited 2009-05-27 12:16

  Somebody said...
  Or are you replacing the continuous rotation servos with a pair of DC motors

  that would be it
  i would be replacing the servos with dc motors
• Mike Green Posts: 23,101

  2009-05-27 17:02 edited 2009-05-27 17:02

  The "Roaming with the BoeBot" code puts all of the wheel movement control in subroutines called Forward_Pulse, Turn_Right, Turn_Left, and Back_Up. Once you get your H-bridge working, you just need to substitute the equivalent H-bridge routines for the existing servo routines. The comments in the program describe what these routines do in terms of movement. How you accomplish that with the DC motors and H-bridges will depend on the specifics of what you build.
• Franklin Posts: 4,747

  2009-05-27 19:22 edited 2009-05-27 19:22

  Somebody said...
  i was asking how to modify the code to work with an H bridge
  that was the base code that i had started from

  What is the H bridge you are using or could you attach a schematic for it? They don't all work the same.
  
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  - Stephen
• invad8er Posts: 14

  2009-05-27 20:48 edited 2009-05-27 20:48

  closest circuit diagram i could find

  

  

  FL2F2I2F54HJ76H.MEDIUM.jpg

  560 x 382 - 21K

  FL2F2I2F54HJ76H.MEDIUM.jpg 21K
• Ugha Posts: 543

  2009-05-28 00:17 edited 2009-05-28 00:17

  What is the brand and model of the H-bridge?
• invad8er Posts: 14

  2009-05-28 00:50 edited 2009-05-28 00:50

  i don't think there is a model or brand for the h-bridge
  i had made the h-brige
• Franklin Posts: 4,747

  2009-05-28 03:20 edited 2009-05-28 03:20

  Get the PDFs from the parallax site on industrial control it might help There are several good instruction PDFs there along with the Nuts and Volts articles on the Parallax products. You can test your H bridge with jumper wires until you understand what you need to do to make it work and then write code to do the same thing.
  
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  - Stephen