Ho to reuse FullDuplexSerial from multiple COGs? [RESOLVED - use cserial]

Comments

• pullmoll Posts: 817

  2010-05-04 07:35 edited 2010-05-04 07:35

  You are starting the debug object twice, which doesn't work, because two cogs will be writing to the same pins. Only because you have a 1 second delay and 2 cogs running asynchronously you get the "MAIN" twice.
  
  What you would have to do is to write an object that can stuff data to the tx buffer of the (once) running fd object. Therefore you need to know the fd object's tx_head, tx_tail and tx_buffer pointers. You would then do the same as the fd.tx itself does: check if long[noparse]/noparse]tx_head_ptr]+1 == long[noparse][[/noparse]tx_tail], and wait if they are equal. Otherwise write byte[noparse][[/noparse]tx_buffer][noparse][[/noparse]long[noparse][[/noparse]tx_head := data and add 1 to the head with wrapping at the buffer size: long[noparse][[/noparse]tx_head_ptr] := (long[noparse][[/noparse]tx_head_ptr] + 1) & 15
  In code - add this to FullDuplexSerial.spin

  
  PUB get_tx_head
    return @tx_head
  
  PUB get_tx_tail
    return @tx_tail
  
  PUB get_tx_buffer
    return @tx_buffer
  
  

  
  
  
  and in your debug.init code write:

  
  PUB init(head, tail, buffer)
     tx_head_ptr := head
     tx_tail_ptr := tail
     tx_buffer_ptr := buffer
  
  PUB chr(ch)
  '' Print a character by stuffing it to the tx buffer of a running FullDuplexSerial object
     repeat while ((long[noparse][[/noparse]tx_head_ptr] + 1) & 15) == long[noparse][[/noparse]tx_tail_ptr]
     byte[noparse][[/noparse]tx_buffer_ptr][noparse][[/noparse]long[noparse][[/noparse]tx_head_ptr]] := ch
     long[noparse][[/noparse]tx_head_ptr] := (long[noparse][[/noparse]tx_head_ptr] + 1) & 15
  
  PUB str(strptr) | index
  '' Print a NUL terminated string
     repeat index from 0 to strsize(strptr)
        chr(byte[noparse][[/noparse]strptr][noparse][[/noparse]index])
  
  PUB dec(value) | _i
  '' Print a decimal number
      result := 0
      if value < 0
          chr("-")
          if (value == NEGX)
              chr("2")
              value += 2_000_000_000
          -value
      _i := 1_000_000_000
      repeat 10
          if value => _i
              chr(value / _i + "0")
              value //= _i
              result~~
          elseif result or _i == 1
              chr("0")
          _i /= 10
  
  PUB hex(value, digits)
  '' Print a hexadecimal number
  
      value <<= (8 - digits) << 2
      repeat digits
          chr(lookupz((value <-= 4) & $F : "0".."9", "A".."F"))
  
  
  DAT
  tx_head_ptr   long 0
  tx_tail_ptr   long 0
  tx_buffer_ptr  long 0
  
  

  
  
  
  The other methods of debug should then use chr(ch) to send bytes to the fd object.
  From main you call fd.init() once and then debug.init(fd.get_tx_head, fd.get_tx_tail, fd.get_tx_buffer) to setup the pointers.
  
  Every object that wants to use debug would then have to be passed the 3 pointers as well. You could set up an array of 3 longs and put the 3 pointers in there, then you'd have to pass just the address of that array to your objects, which would then call debug.init() with the 3 values from the array.
  
  Locking is not strictly necessary, but if you want to add it, you would pass the lock handle as well and try to acquire the lock at the start of each function in debug.spin, then release it at the end of the function.
  
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  Pullmoll's Propeller Projects
  
  Post Edited (pullmoll) : 5/4/2010 8:05:02 AM GMT
• Dave Hein Posts: 6,347

  2010-05-04 13:54 edited 2010-05-04 13:54

  The cserial.spin object in CLib can handle multiple cogs.· You call it the same way you would call the FullDuplexSerial methods, except you set bit 4 in the mode flag to make it·cog-safe.· You would call the start·function as follows:
  
  · fd.start(31, 30, %10000, 115200)
  
  The·start method·should only be called once, normally from cog 0 in the top object.· Check out the test program in CLib.· I have several cogs waiting on the same flag, and then they all print at the same time.
  
  You can download CLib from the OBEX at http://obex.parallax.com/objects/594/·.
  
  Dave
• Dave Hein Posts: 6,347

  2010-05-04 15:17 edited 2010-05-04 15:17

  Just to make it clear your source files would be as follows:
  
  main.spin
  

  CON
      _CLKMODE = XTAL1 + PLL8X
      _CLKFREQ = 96_000_000
  OBJ
      debug: "cserial"
      another: "another"
  PUB main
      debug.start(31, 30, %10000, 115200)
      another.start
      repeat
          debug.str(string("MAIN", $0D))
          WAITCNT(CLKFREQ + CNT)
  
  

  
  another.spin
  

  OBJ
      debug: "cserial"
  var 
      LONG stack[noparse][[/noparse]32]
  PUB start
      CogNew(main, @stack)
  PUB main
      repeat
          debug.str(string("ANOTHER", $0D))
          WAITCNT(CLKFREQ + CNT)
  
  

  
  I have also attached cserial.spin.
  
  Dave

  spin

  spin

  cserial.spin

  31K

  cserial.spin 31.2K
• Andrey Demenev Posts: 386

  2010-05-05 01:32 edited 2010-05-05 01:32

  Dave, tanks a lot! this works just great!