Variable Pin # in PULSOUT

John Couture

I feel like I am missing something obvious.· I want to put the Pulsout command into a subroutine and be able to supply it with a variable pin number.

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John J. Couture

San Diego Miramar College

Velocit

You can't pass pins through subroutine parameters, nor can you use a variable to declare a pin in the PULSOUT command. Also, the intermediate variables, ServoNum and ServoDur, aren't necessary ; you can save memory by doing away with them. Here's an example of how you might implement your code:

Main:
  SERVO 1,150
  SERVO 0,100
  goto main

' -----------------------------------------------------------
' Subroutine Code
' -----------------------------------------------------------
SERVO:
' USE: SERVO servo#, pulse duration
    IF __PARAM1 = 1 THEN
        PULSOUT Servo_Grip, __PARAM2
    ELSE
        PULSOUT Servo_Base, __PARAM2   
    ENDIF
ENDSUB

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-Paul

Post Edited (Velocit

JonnyMac

The cool thing about SX/B is that you can create you own routines. I just wrote this off the top of my head but am pretty confident it will work fine:

' Use: PULSE_OUT pin, timing
' -- pin is 0 to 15 (RB.0 to RC.7)
' -- timing is in microseconds

SUB PULSE_OUT
  IF __PARAMCNT = 2 THEN
    tmpB1 = __PARAM1
    tmpW1 = __PARAM2
  ELSE
    tmpB1 = __PARAM1
    tmpW1 = __WPARAM23
  ENDIF
  
  tmpW2 = 1 << tmpB1                            ' create pin mask
  RBC = RBC XOR tmpW2                           ' toggle the pin
  PAUSEUS tmpW1                                 ' wait
  RBC = RBC XOR tmpW2                           ' toggle back
  ENDSUB

John Couture

Interesting.· Thank you all.· We'll try that in class and see what happens!

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John J. Couture

San Diego Miramar College

JonnyMac

John,

Note that my version (above) does not make the pin an output; you should make any pin that will be pulsed an output and it the non-pulse state before using the routine.

Another great thing about SX/B is that you can mix assembly into BASIC, and use interrupts. I've attached reasonably-simple program that has an eight-channel virtual servo controller connected to RB.0 to RB.7. EFX-TEK customers do a lot of servo animations so this framework makes things easy on them; all they have to do is tell a servo where to be in the foreground (via the pos array) and the ISR takes care of the rest -- for up to eight servos.

Post Edited (JonnyMac) : 4/12/2008 9:41:46 PM GMT