walk/chew gum....simultaniously

Comments

• Mike Green Posts: 23,101

  2007-11-20 23:31 edited 2007-11-20 23:31

  Servos generally require a control pulse every 20ms. That leaves quite a bit of time to do other things like flash LEDs. If you're controlling 2 servos, that's at most 5ms (2 x 2.5ms) for the control pulses leaving 20ms - 5ms = 15ms. Alternatively, you could use something like the new ServoPAL to take over the servo pulses and do whatever you wanted with the LEDs.
• Zoot Posts: 2,227

  2007-11-21 03:57 edited 2007-11-21 03:57

  As usual, Mike is right -- 20ms is enough time to do other stuff, and it's actually pretty fast -- if you blink your LEDs that fast, you won't see them blink...
  
  This might give you an idea of how to tackle it:
  
  

  ledCntr VAR Byte  'time slice
  speedL VAR Byte  'motor speed
  speedR VAR Byte  'motor speed
  
  motoL PIN 0
  motoR PIN 1
  leds VAR OUTC '4 leds on output states of pins 8-11
  
  DIRC = %1111 'make leds outputs
  
  leds = %0101 'turn on two of 'em
  
  Main:
  
     ' the goal is for the main loop to take about 20ms including send time on the pulses
    ' do some stuff
    speedL = 120
    speedR = 170
    'IF obstacle, change speed, etc
    'more stuff
     
  Update_Leds:
     ledCntr = ledCntr + 1 'each pass through loop increment counter -- each "tick" = ~20ms
     IF ledCntr = 5 THEN   'every 100ms (approx.) change the LEDs -- this is still pretty fast
        ledCntr = 0            'reset counter
        leds = ~leds         'just invert 'em, or put lots of fancy patterns here. Make the "5" above a variable to change speed of pattern "on the fly"
     ENDIF
  
  Send_Motors:
    GOSUB SEND_PULSES
  
  End_Main_Loop:
      'PAUSE 5  '---- strictly optional pause IF you need to pad the loop -- usually you will be tight, not loose, but you never know
      GOTO Main
  
  '-----------
  SEND_PULSES:
     'PULSOUT motoL, speedL, etc
     'PULSOUT motoR, speedR, etc
     RETURN
  
  
  

  
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  When the going gets weird, the weird turn pro. -- HST
• Husky X3 Posts: 18

  2007-11-26 23:02 edited 2007-11-26 23:02

  Thanks Mike, but it was not the amount of time I had left over. Merely the fact that the Boe-bot would stop the servos to flash the LEDs, and then continue it's foward travel. I will check out the ServoPal, but ultimately I would like to run the the LED'S and sevos from the same MC ( bs2-ic ).
  
  
  · AJ
  
  P.S.
  that is some code, Zoot, thanks. I will give it a shot.
  
  
  i APPRECIATE EVERYONE'S HELP AND COMMENTS! thank you all.
  
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  PSALM 23
• Franklin Posts: 4,747

  2007-11-27 02:26 edited 2007-11-27 02:26

  Post your code and maybe we could find ways to help.
  
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  - Stephen
• stephenwagner Posts: 147

  2007-11-27 13:08 edited 2007-11-27 13:08

  Try this.
  'Output Pins
  LEDPIN1 PIN ??
  LEDPIN2 PIN ???
  
  DO
  
  Hight LEDPIN1
  Low LEDPIN2
  
  FOR idx = 1 to 50
  
  GOSUB YourCodeToControlServo
  
  NEXT
  
  LOW LEDPIN1
  High LEDPIN2
  
  FOR idx = 1 to 50
  
  GOSUB YourCodeToControlServo
  
  NEXT
  
  LOOP
  
  YourCodeToControlServo:
  Your code goes here as a sub.
  RETURN
  
  Change the value(s) of idx to suit your needs.
  
  You might also want to try RANDOM and OUTS in place of the High and Low.
  
  I hope this helps.
  
  SJW
• Mike Green Posts: 23,101

  2007-11-27 15:38 edited 2007-11-27 15:38

  Husky X3,
  What we're saying is that you have to interleave the servo handling and the LED handling rather than do one, than the other. It is certainly clearer and more straightforward to use something like a ServoPAL, but the Stamps can handle servos and LEDs at the same time with the interleaving.