BOE BOT jitter… Smother move?

Comments

• W9GFO Posts: 4,010

  2010-06-09 02:09 edited 2010-06-09 02:09

  Your subroutines have awful short pauses. The servos need a pulse every 20 or so milliseconds. Each command takes a short time to execute so the length of the pause will be variable depending upon what else is happening in your loop. In your case there is nothing else going on in the loop so your pause should be longer. Try PAUSE 18 for each of them, PAUSE 20 is fine too but PAUSE 3 or PAUSE 5 will likely cause your servos to respond in undesirable ways.
  
  Eek! I just noticed that you have commented out your pauses. So what is happening is you are sending three pulses, each only a couple milliseconds apart. Your servos aren't going to be liking that.
  
  If after changing the pause times you still do not get smooth movement it would be because RCTIME is taking too long. You could either try a smaller capacitor or read only one of the ir detectors each time through the loop. If you did that you could also change your movement subroutines so that the pulses are sent only once each time.
  
  Rich H
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  The Simple Servo Tester, a kit from Gadget Gangster.
  
  Post Edited (W9GFO) : 6/9/2010 2:22:14 AM GMT
• Shane Weddle Posts: 4

  2010-06-09 15:50 edited 2010-06-09 15:50

  I will give that a shot, I was thinking the pauses created the jitters, When I have PAUSE 20 in place its a longer forward movement but less granularity in the detection of a line.
  The hole RCTIME operation seams to be a bit consuming... Oh for the love having Analog in...
  
  Shane
• W9GFO Posts: 4,010

  2010-06-09 18:44 edited 2010-06-09 18:44

  I would eliminate the FOR..NEXT loop so that for each time the line sensors is checked, only one pulse is sent to the servos. To get your program running smoothly you will need to get the sensor checking portion of it to take 20 milliseconds (or so) to execute. Since you only send one pulse to the servos AND the sensor checking will be taking about 20 milliseconds then you do not need pauses in the subroutines (except for the backing up one).
  
  

  ' {$Stamp bs2} ' Stamp directive.
  ' {$PBASIC 2.5} ' PBASIC directive.
  
  ' -----[noparse][[/noparse] Variables ]----------------------------------------------------------
  
  irDetectLeft    VAR   BIT
  irDetectRight   VAR   BIT
  timeLeft        VAR   WORD
  timeRight       VAR   WORD
  pulseCount      VAR   BYTE   
  
  DO
  
    FREQOUT 8, 1, 38500
    HIGH 6
    HIGH 5
    PAUSE 2
    RCTIME 6,1,timeLeft
    RCTIME 5,1,timeRight
  
    PAUSE 15                ' adjust as needed
  
    IF (timeLeft > 1300) AND (timeRight > 1300) THEN  'SEEING ALL BLACK, BACK UP.
      GOSUB Back_Up
    ELSEIF timeLeft > 1300 THEN                       'TURN RIGHT.. SEEING BLACK ON LEFT
      GOSUB Turn_Right
    ELSEIF timeRight > 1300 THEN                      'TURN LEFT... SEEING BLACK ON RIGHT
      GOSUB Turn_Left
    ELSE                                              'GO FORWARD... SEEING WIGHT ON BOTH
      GOSUB Forward_Pulse
    ENDIF
  
  LOOP
  
  ' -----[noparse][[/noparse] Subroutines ]--------------------------------------------------------
  'STOP = 760
  
  Forward_Pulse: 
    PULSOUT 13,850 'LEFT
    PULSOUT 12,650 'RIGHT
  RETURN
  
  Turn_Left: 
    PULSOUT 13, 850
    PULSOUT 12, 760
  RETURN
  
  Turn_Right: 
    PULSOUT 13, 760
    PULSOUT 12, 650
  RETURN
  
  Back_Up: 
    FOR pulseCount = 0 TO 40
      PULSOUT 13, 650
      PULSOUT 12, 850
      PAUSE 18
    NEXT
  RETURN
  
  END
  

  
  
  
  Rich H
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  The Simple Servo Tester, a kit from Gadget Gangster.
  
  Post Edited (W9GFO) : 6/9/2010 6:53:26 PM GMT
• Shane Weddle Posts: 4

  2010-06-09 19:44 edited 2010-06-09 19:44

  Thanks W9GFO, I'll give that a shot!