Another round of passing data

bdickens · 2008-01-30 12:44

Can someone point me to some simple examples in SPIN where two or more COGS are accessing the same set of data ? I see some assembler, but I'd rather not add to my list. The application has a sensor package that is posting an array of longs. Two other COGS are running and use the data (one to make physical changes, one to log to storage). I'm pretty new to this so simple is best.

Thanks

Martin Hebel · 2008-01-30 12:50

Simply create a global variable and use that same variable in two different methods running in different cogs. Almost too simple for an example [noparse]:)[/noparse]

As long as you aren't using data sizes bigger than longs, it doesn't take much. Any longer and you'll have to start dealing with methods to synch using locks or what not.

-Martin

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Joerg · 2008-01-30 12:57

I had the same needs and here is how i solved it (Thanks to all helpers from this forum!)

Here the routine running on the first cog

{{MotionController2.spin}}

VAR
    long StepTime
    long ActPos
    long RefPos
    byte MotStat
    byte SynchControl

    byte Pin0

OBJ
  Motion : "Stepper_A2919"


PUB Main

  StepTime := 100_000
  MotStat := 0
  Pin0 := 0

  Motion.Start(Pin0,@MotStat,@StepTime)

  repeat
    if ina[noparse][[/noparse]11..8] == 14
      MotStat := 1
    elseif ina[noparse][[/noparse]11..8] == 12
      MotStat := 3  
    else
      MotStat := 0

and here the routine(s) running on an other:

'stepper_A2919
{{MotStat
  Bit   7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |    State:  0         |  1   
        I   I   I   I   I   I   I   I------->      Stop      |  Run           
        I   I   I   I   I   I   I----------->      Forward   |  Backward
        I   I   I   I   I   I--------------->      Halfstep  |  Fullstep     not implemented yet
        I   I   I   I   I------------------->      SPhase    |  TPhase       not implemented yet
        I   I   I   I----------------------->      Continous |  Controled    not implemented yet
        I   I   I--------------------------->                NU
        I   I------------------------------->                NU
        I----------------------------------->                NU

Pin0   = P1
Pin0+1 = P2
Pin0+2 = P3
Pin0+3 = P4

P5 = VSS!!! (GND)

}}

VAR
  long  Stack[noparse][[/noparse]14]                     'Stack space for new cog
  byte  Cog                           'Hold ID of cog in use, if any
  byte  StepNr                        'the actual step number
  long  MCounter                      'counter to hold the waitcycles

CON
  Run = 1                             
  Backward = 2
  FullStep = 4
  TPhase = 8
  Synch = 128                   

PUB Start(Pin0,AdrMotStat, AdrStepTime): Success

  Stop
  Success := (Cog := cognew(ManageMotor(Pin0,AdrMotStat, AdrStepTime), @Stack) + 1)

PUB Stop
{{Stop toggling process, if any.}}

  if Cog
    cogstop(Cog~ - 1)

PUB ManageMotor(Pin0, AdrMotStat, AdrStepTime)

  StepNr~                                               'clear the StepNr counter
  dira[noparse][[/noparse]Pin0+7 .. Pin0]~~                                'sets the needed pins as output
  
  repeat
    repeat until byte[noparse][[/noparse]AdrMotStat] & Run                 'wait until motor has to run!

    if byte[noparse][[/noparse]AdrMotStat] & Backward

      --StepNr                                          'backward
      if StepNr == 255
        StepNr := 7
   
    else
      ++StepNr                                          'foreward
      if StepNr > 7
        StepNr := 0    


    outa[noparse][[/noparse]Pin0+3 .. Pin0] := STEPTBL[noparse][[/noparse]StepNr]                  'set the outputs depending on the StepNr
    waitcnt(clkfreq / 1_000_000 * long[noparse][[/noparse]AdrStepTime]  + cnt)  'Wait for steptime cycles

     
      
DAT

STEPTBL       byte    4, 0, 1, 2, 6, 10, 9, 8       'table for controling the motor (halfsteps)

This is a stepper motor routine that (when finished!?) will run some stepper motors simultaneous controlled by the main program!

Saluti Joerg

bdickens · 2008-01-30 20:09

Perfect. Thank you both. That will work nicely.

Another round of passing data

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