Help with simultaneous control of 2 stepper motors using Propeller

kotsos

Hi,
What I basically aim to do is to control many (4 in total) stepper motors SIMULTANEOUSLY using the propeller. I wrote an object that successfully controls 1 stepper motor, but when I try to launch the object multiple times, it doesn't work!
This is the code of the object:

_xinfreq = 5_000_000                     
_clkmode = xtal1 + pll1x

DAT

Steps byte %1100, %0110, %0011, %1001

VAR

long cntr, stpIdx
long stack[200]
byte cog

PUB Start(P1, P4, nxt, prev) : success

Stop
success := (cog := cognew(gostep(P1, P4, nxt, prev), @stack)+1)    

PUB Stop

if cog
  cogstop(cog~ -1)
  
PUB gostep(P1, P4, nxt, prev)

    dira[19..22]~~
    outa[19..22]~~
    dira[28..31]~~
    outa[28..31]~~
    
  if prev < nxt
    stepFwd(P1,P4,(nxt-prev))
    
  elseif prev > nxt
    stepBwd(P1,P4,(prev-nxt))

    
PUB stepFwd(P1,P4,stps)
     
    repeat  cntr from 1 to stps
       stpIdx := ++stpIdx // 4
       outa[P1..P4] := Steps[stpIdx]
       waitcnt(clkfreq/200 + cnt)

PUB stepBwd(P1,P4,stps)

    repeat  cntr from 1 to stps
       stpIdx := (stpIdx + 3) // 4
       outa[P1..P4] := Steps[stpIdx]
       waitcnt(clkfreq/200 + cnt)

This is the script that calls the object:

_xinfreq = 5_000_000                     
_clkmode = xtal1 + pll1x

VAR

long cntr, stpIdx 

OBJ

stepper : "Stepper_motor_trials"

PUB launchStepper

    
   stepper.Start(28,31, 200, 0)
   stepper.Start(19,22, 200, 0)

Any suggestions on how to launch the object "stepper" on multiple cogs?
Right now all it excecutes is what "stepper.Start(19,22, 200, 0)" does. I suspect that for some reason when I try to launch a second cog, I stop the previous one.

Thanks in advance!
-kotsos

kuroneko

_xinfreq = 5_000_000                     
_clkmode = xtal1 + pll1x

VAR

long cntr, stpIdx 

OBJ

stepper[COLOR="red"][2][/COLOR] : "Stepper_motor_trials"

PUB launchStepper

    
   stepper[COLOR="red"][0][/COLOR].Start(28,31, 200, 0)
   stepper[COLOR="red"][1][/COLOR].Start(19,22, 200, 0)

You do need two instances of the same object. Previously you simply re-started the one stepper object you had. Also, the hardwired dira/outa assignments in the gostep method look suspicious.

kotsos

I tried your correction and nothing moves! Without defining two instances of the object, the last motor moves as it should. Any suggestions?

kuroneko

Are you sure you want to play around with pins 28..31? Those are usually occupied by the EEPROM and the PC link. Also, did you clean up the gostep method? Starting the first object will set pins 19..22 and 28..31 to high. Only 28..31 are subsequently changed. Same with the second object, all 8 pins are set high, then 19..22 are changed. The thing with high outputs is that they block any attempt of other cogs to change the pins (wired OR). IOW, the first object is blocking the second's outputs and vice versa. So you should change your code to only touch the pins you are actually driving.

kotsos

That's the correction that I did to the method "launchStepper":

PUB launchStepper

   dira[28..31]~~
   outa[28..31]~~ 
   stepper[0].Start(28,31, 200, 0)

   dira[19..22]~~
   outa[19..22]~~ 
   stepper[1].Start(19,22, 200, 0)

Still nothing moves.
How do I clean the gostep method, as you mentioned?

Thanks!

kotsos

Wait!
I got it!!!

I re-corrected the dira/outa thing. Here is the code:

_xinfreq = 5_000_000                     
_clkmode = xtal1 + pll1x

DAT

Steps byte %1100, %0110, %0011, %1001

VAR

long cntr, stpIdx
long stack[200]
byte cog

PUB Start(P1, P4, nxt, prev) : success

Stop
success := (cog := cognew(gostep(P1, P4, nxt, prev), @stack)+1)    

PUB Stop

if cog
  cogstop(cog~ -1)
  
PUB gostep(P1, P4, nxt, prev)

   dira[P1..P4]~~
   outa[P1..P4]~~
   
  if prev < nxt
    stepFwd(P1,P4,(nxt-prev))
    
  elseif prev > nxt
    stepBwd(P1,P4,(prev-nxt))

    
PUB stepFwd(P1,P4,stps)
     
    repeat  cntr from 1 to stps
       stpIdx := ++stpIdx // 4
       outa[P1..P4] := Steps[stpIdx]
       waitcnt(clkfreq/200 + cnt)

PUB stepBwd(P1,P4,stps)

    repeat  cntr from 1 to stps
       stpIdx := (stpIdx + 3) // 4
       outa[P1..P4] := Steps[stpIdx]
       waitcnt(clkfreq/200 + cnt)

And

_xinfreq = 5_000_000                     
_clkmode = xtal1 + pll1x

VAR

long cntr, stpIdx 

OBJ

stepper[2]: "Stepper_motor_trials"

PUB launchStepper

   stepper[0].Start(28,31, 200, 0)

   stepper[1].Start(19,22, 200, 0)

Thanks A lot! You solved my problem!!!!!