WAM Ch. 4 Exercise 1/2

Comments

• kf4mat Posts: 21

  2005-10-23 22:35 edited 2005-10-23 22:35

  Well, after much nashing of teeth I seem to have devised a way to make the exercise work. see attached if interested.
  
  Tom

  bs2

  bs2

  ex2ch4.bs2

  349B

  ex2ch4.bs2 349B
• Andy Lindsay (Parallax) Posts: 1,919

  2005-10-24 00:58 edited 2005-10-24 00:58

  Hi Tom,
  
  Working straight from the questions as they are posted, this is what I think the answers should be:
  
  

  [color=green]' Solutions - I think.bs2[/color]
   
  [color=green]' {$STAMP BS2}[/color]
  [color=green]' {$PBASIC 2.5}[/color]
   
  [color=#000000]counter VAR Word[/color]
  [color=#000000]pulses  VAR Nib[/color]
   
  [color=green]' Chapter 4, Exercise 1-a[/color]
   
  [color=#0000ff]FOR[/color][color=#000000] counter = 700 [/color][color=#0000ff]TO[/color][color=#000000] 800[/color]
    [color=#0000ff]PULSOUT[/color][color=#000000] 14, counter[/color]
    [color=#0000ff]PAUSE[/color][color=#000000] 20[/color]
  [color=blue]NEXT[/color]
   
  [color=green]' Chapter 4, Exercise 1-b[/color]
   
  [color=#0000ff]FOR[/color][color=#000000] counter = 700 [/color][color=#0000ff]TO[/color][color=#000000] 800 [/color][color=#0000ff]STEP[/color][color=#000000] 4[/color]
    [color=#0000ff]PULSOUT[/color][color=#000000] 14, counter[/color]
    [color=#0000ff]PAUSE[/color][color=#000000] 20[/color]
  [color=blue]NEXT[/color]
   
  [color=green]' Chapter 4, Exercise 2[/color]
   
  [color=#0000ff]FOR[/color][color=#000000] counter = 700 [/color][color=#0000ff]TO[/color][color=#000000] 800 [/color][color=#0000ff]STEP[/color][color=#000000] 4[/color]
    [color=#0000ff]FOR[/color][color=#000000] pulses = 1 [/color][color=#0000ff]TO[/color][color=#000000] 10[/color]
      [color=#0000ff]PULSOUT[/color][color=#000000] 14, counter[/color]
      [color=#0000ff]PAUSE[/color][color=#000000] 20[/color]
  [color=blue]  NEXT[/color]
  [color=blue]NEXT[/color]
  
  

  
  
  
  They are not tested.· Please try them out and let me know if they work.
  
  Regards, Andy
  
  Post Edited (Andy Lindsay (Parallax)) : 10/24/2005 1:03:40 AM GMT

  bs2

  bs2

  Solutions - I think.bs2

  442B

  Solutions - I think.bs2 442B
• kf4mat Posts: 21

  2005-10-24 20:33 edited 2005-10-24 20:33

  Andy Lindsay said...
  ' Chapter 4, Exercise 2
  ·
  FOR counter = 700 TO 800 STEP 4
  · FOR pulses = 1 TO 10
  ··· PULSOUT 14, counter
  ··· PAUSE 20
  · NEXT
  NEXT
  

  Hi Andy, the above code block does not work with regards to question 2. In order to see if it worked I added another line after the pause 20 to watch the counter:
  
  ······· DEBUG DEC3 counter, CR, CRSRUP
  
  When you run it the debug terminal counts in steps of 4 starting from 700. So then I changed it to read the value of pulses, when you run it then the debug terminal counts from 1 to 10 over and over until the value of counter gets to 800.
  
  The only way I could get it to work the way the question is worded was to add a nested IF...THEN statement· See the attachment on my second post. That way the value of counter as displayed on the debug terminal counts from 700 to 710 by 1's and then counts the rest of the way by 4's. It works but I don't know if nesting a IF...THEN inside a FOR...NEXT is considered good pratice.
  
  Tom
• Andy Lindsay (Parallax) Posts: 1,919

  2005-10-24 22:13 edited 2005-10-24 22:13

  Tom,
  
  I think you will see it better if you use
  
  · DEBUG ? counter
  
  instead.··Here, try this one:
  
  ' Chapter 4, Exercise 2
  ·
  FOR counter = 700 TO 800 STEP 4
  · FOR pulses = 1 TO 10
  ··· PULSOUT 14, counter
  ··· ' PAUSE 20
  ··· DEBUG ? counter
  · NEXT
  NEXT
  
  The result in the Debug Terminal should display counter = 700 ten times, followed by counter = 704 ten times, and so on up to counter = 800 ten times.· Keep in mind that the counter variable is the PULSOUT command's duration argument in the solution.
  
  These nested loops are important.· The net effect is that it causes the servo to hold the 700 position for about 1/10 second, followed by the 710 <edit>, no, it's actually 704 </edit> position for about 1/10 of a second, and so on.·
  
  The results will probably be more visible on the servo with this kind of subroutine (without the DEBUG command):
  
  ' Another example - 9 positions, 3/4 seconds each
  ·
  FOR counter =·350 TO·1150 STEP 100
  · FOR pulses = 1 TO 32
  ··· PULSOUT 14, counter
  ··· PAUSE 20
  · NEXT
  NEXT
  
  Lots of machines are programmed with that kind of loop.· The other day on the news, I saw one of those biomedical machines that puts a drop of solution on hundreds of different test slides.· While the motors and the microcontroller's programming language are likely different, it·almost certainly still uses nested loops to advance the plate of slides to one position, stay there for a while the eye dropper does its thing, then advance to the next position, etc.
  
  Regards, Andy
  
  Post Edited (Andy Lindsay (Parallax)) : 10/24/2005 10:16:30 PM GMT
• kf4mat Posts: 21

  2005-10-24 23:59 edited 2005-10-24 23:59

  ·Well now, things are kinda making sense. This whole time I've been misinterperting the question.
  

  Andy Lindsay said...
  These nested loops are important.· The net effect is that it causes the servo to hold the 700 position for about 1/10 second, followed by the 710 <edit>, no, it's actually 704 </edit> position for about 1/10 of a second, and so on.·
  

  I've been reading it as you want the servo to advance by steps of·1, from 700 to 710 and then starting at 711 start advancing by steps of 4. Not sure I would have understood that without your help.
  
  Thanks alot,
  
  Tom