Starting and stopping a cog with a push button

Comments

• Mike G Posts: 2,702

  2011-10-11 20:48 edited 2011-10-11 20:48

  How about posting your code? That way folks can get an idea of what you're trying to do.
• Mike Green Posts: 23,101

  2011-10-11 21:19 edited 2011-10-11 21:19

  You don't actually want the cog to disable (stop) itself. Typically, when a cog is started, it continues to run indefinitely. It may wait for an I/O pin to reach a specific state or it may wait for a particular time to arrive (up to about 50 seconds in the future). The power consumption of the cog will drop markedly when it's waiting using any of the WAITxxx instructions / statements. Remember that it takes on the order of 100us to start up a cog to begin with. If you use COGSTOP to stop the cog, that resets it. It would have to be started up all over again from scratch using COGNEW or COGINIT.
  
  
  
  To pause until a switch changes state, you'd want to use WAITPEQ or WAITPNE. Look up the explanations in the Propeller Manual.
• Ariba Posts: 2,694

  2011-10-11 22:16 edited 2011-10-11 22:16

  Here is short code that makes what you want:

  CON
    LED    = 16                         'pin numbers
    button = 0
  
  VAR long stack[20]
  
  PUB ATest : run | cog
   repeat
     if ina[button]==0 and run==0       'if not button and not running
       run := 1                         'start blink cog
       cog := cognew(Blink,@stack)
       delay(50)                        'debounce
     elseif ina[button]==1 and run==1   'if button and running
       run := 0                         'stop blink cog
       cogstop(cog)
       delay(50)                        'debounce
  
  PRI Blink                             'cog routine
   dira[LED] := 1
   repeat
     !outa[LED]                         'blink a LED
     delay(250)
  
  PUB delay(ms)
    waitcnt(clkfreq/1000*ms + cnt)
  

  
  Andy
• mattbutsko Posts: 8

  2011-10-12 08:27 edited 2011-10-12 08:27

  Ariba wrote: »

  Here is short code that makes what you want:

  CON
    LED    = 16                         'pin numbers
    button = 0
   
  VAR long stack[20]
   
  PUB ATest : run | cog
   repeat
     if ina[button]==0 and run==0       'if not button and not running
       run := 1                         'start blink cog
       cog := cognew(Blink,@stack)
       delay(50)                        'debounce
     elseif ina[button]==1 and run==1   'if button and running
       run := 0                         'stop blink cog
       cogstop(cog)
       delay(50)                        'debounce
   
  PRI Blink                             'cog routine
   dira[LED] := 1
   repeat
     !outa[LED]                         'blink a LED
     delay(250)
   
  PUB delay(ms)
    waitcnt(clkfreq/1000*ms + cnt)
  

  
  Andy

  
  
  Thanks everyone, but specifically Andy for the example. I can definately build what I need out of this.
• Ray0665 Posts: 231

  2011-10-12 09:53 edited 2011-10-12 09:53

  You can also stop and start cogs explicitly

  CON
    _CLKMODE  = XTAL1 + PLL16X
    _XINFREQ  = 5_000_000
  
    clock     = 80_000_000
    ms1       = clock / 1000
    
    Led1      = 16                         'pin assignments
    led2      = 23
    button    = 0
  
  VAR long stack[10]
  
  PUB ATest | state
    state := 0                                   ' Initial state for normally open button 
  ' state := 1                                   ' initial state for normally closed button 
   repeat
     case ina[button]                
        0: if state==0                          ' if in run state 0
              cogstop(6)                        ' Stop running cog
              coginit(2,Blink(Led1),@stack)     ' Start Blink in cog A
              state:=1                          ' indicate run state 1
        1: if state==1                          ' if in run state 1
              cogstop(2)                        ' Stop Blink in running cog
              coginit(6,Blink(Led2),@stack)     ' Start Blink in cog B  
              state := 0                        ' indicate state 0
     delay(50)                                  ' for switch debounce
  
  PRI Blink(Pin)                  ' cog routine
   dira[Pin]~~
   repeat
     !outa[Pin]                   ' blink a LED
     delay(250)
  
  PUB delay(ms)
    waitcnt(clkfreq/1000*ms + cnt)