Motors do not work on BS2PX

Comments

• Mike Green Posts: 23,101

  2017-09-26 14:40 edited 2017-09-26 14:43

  The BS2px runs at a higher speed than the BS2 and most of the statements that involve timings are affected (except PAUSE). In your case the timings of the pulses with PULSOUT are different. For the BS2, each count is 2us. For the BS2px, each count is 0.8us. A PULSEOUT HB25,750 results in a 1500us pulse on the BS2. You need a PULSOUT HB25,1875 on the BS2px to get the same width pulse. That's 2.5 times larger (multiply by 5, then divide by 2)
• ptruini Posts: 9

  2017-09-27 19:17

  Thank you Mike! I figured it was something that was different between the two; the motors are moving now, I just need to tweak it to have them move to my liking.
  
  Thank you and have a blessed day!
  Paul
• Genetix Posts: 1,774

  2017-09-27 20:29 edited 2017-09-27 20:32

  Paul,
  
  I've been looking over your program and I noticed a few things:
  Twice in your program you switch to Voice 4, using ":-)4", so why not just change to Voice 4 after you set the volume to maximum.

  SEROUT EMIC_TX, EmicBaud, ["N4", CR]
  SERIN EMIC_RX, EmicBaud, [WAIT(":")]
  

  
  The PIR documentation initializes with only this instead of the strange DO...LOOP you use and I/O pins starts as Inputs.

  PAUSE 40000   ' PIR warm-up time     [PIR_Simple.bs2]
  

  
  I am guessing you have your LEDs wired to be Active-High or on when the output is high. According to the BASIC Stamp Manual the NAP will momentarily turn off the current to all I/O pins as it wakes up.
  Use PAUSE instead and if you need more time then use a FOR...NEXT loop or several PAUSES in a row.
  
  You have 2 lines in each part your IF...THEN...ELSE that display the status of the PIR sensor using IN10. You are using PIR for pin 10 so change the IN10 to PIR.
  
  The only variable your program uses in pulseCount.
  
  You also need to change the 100 in your FOR...NEXT loops for pulseCount to 250 since the BS2px PULSOUT command uses a smaller time interval than the BS2.
  I don't know what motors you are using but the HB-25 documentation says that pulses of 1 and 2 milliseconds will more the motor at full speed in each direction.
  Remember that the pulse value starts at 1875, which results in a pulse of 1875 x 0.8 = 1.5 ms or motor neutral (off).
  To get the full speed values, remember that 1000 us are in 1 ms since PULSOUT is in us or micro-seconds.

  1 ms = 1000 us, 1000 us / 0.8 us = 1250
  2 ms = 2000 us, 2000 us / 0.8 us = 2500
  

  Those are the PULSOUT full speed values but you need to ramp up to them, so you need to know difference between stop and full.

  2500 - 1875 = 625
  1875 - 1250 = 625
  

  Changing the FOR...NEXT value from 100 to 625 should make your motors run at full speed but you might want to try 300 or 400 first and then increase it until your happy.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• ptruini Posts: 9

  2017-09-28 15:16

  Thank you Genetix for looking so deeply into my program; that was nice of you. Thanks for all the very useful information, I have made necessary adjustments and my Robot is working much better now, still tweaking, but working as I designed. I had the NAP command in there for something I was testing and forgot to take it out. I now changed it to a PAUSE. I modified the PIR warmup from PAUSE 40000 to 10000 to speed up the testing process. All is well now and the timings and duration information is very useful...We both thank you again!
  
  Paul and Dylbot
• Genetix Posts: 1,774

  2017-09-28 18:00 edited 2017-09-28 18:09

  Hello Paul,
  
  Your program already has conditional compilation code for serial baud values so you could add PULSOUT values to the list also.
  Unlike the baud rate, the BS2px uses the same PULSOUT duration as the BS2sx and BS2p.

  #SELECT $STAMP ' Select Baud constants
    #CASE BS2, BS2E, BS2PE
      T1200 CON 813
      T2400 CON 396
      T4800 CON 188
      T9600 CON 84
      T19K2 CON 32
      MotorStop   CON   750   ' PULSOUT duration that stops motor
      RampRange   CON   250   ' PULSOUT duration for ramping range
    #CASE BS2SX, BS2P
      T1200 CON 2063
      T2400 CON 1021
      T4800 CON 500
      T9600 CON 240
      T19K2 CON 110
      MotorStop   CON   1875   ' PULSOUT duration that stops motor
      RampRange   CON   625   ' PULSOUT duration for ramping range
    #CASE BS2PX
      T1200 CON 3313
      T2400 CON 1646
      T4800 CON 813
      T9600 CON 396
      T19K2 CON 188
      MotorStop   CON   1875   ' PULSOUT duration that stops motor
      RampRange   CON   625   ' PULSOUT duration for ramping range
  #ENDSELECT
  

  Then just change the PULSOUT values in the program to these constants.
  
  Some of the code in your program repeats so you might want to consider using subroutines instead.
  For example, you first blink each of the colored LEDs.
  A variable now controls which LED will be blinked and the blink time can be easily changed.

  ' --- New Constants --
    BlinkTime   CON   500   ' Time the LED will blink in milliseconds
  ' -- New Variables ---
    ' Notice that the first letter of a variable is always lower-case
    blinkLED   VAR NIB   ' The pin number of the LED to be blinked
      ' Since there are only 16 I/O pins we can use a Nibble variable
      ' A Nibble variable will hold a value from 0 to 15
  
  ' --- Initialization ---
    ' Blink Red LED
    blinkLED = RLED   ' The Red LED will be blinked
    GOSUB Blink_LED   ' Call the blink subroutine
    ' The program will resume here
  
    ' Blink Green LED
    blinkLED = GLED
    GOSUB Blink_LED
  
    'Blink Blue LED
    blinkLED = BLED
    GOSUB Blink_LED
  
  ' --- Subroutines ---
    ' Subroutines are always placed at the bottom of the program
    ' Notice that subroutines use underscores between the words
  Blink_LED:   ' Blink an LED
    HIGH blinkLED   ' Turn LED on
    PAUSE BlinkTime   ' Keep LED on for blink time
    LOW blinkLED   ' Turn LED off
    RETURN   ' Go back to the program