FullDuplexSerial problem

Comments

• Cluso99 Posts: 18,071

  2013-08-16 06:36 edited 2013-08-16 06:36

  FDS works for all 256 characters. Most likely you are confusing a return value of -1 ($FFFFFFFF).
  It would help if you posted your code.
• OldFartRadioman Posts: 30

  2013-08-16 06:53 edited 2013-08-16 06:53

  The data comes in in 5 byte packets but for some reason once in a while gets out of sync. The timeout is an effort to resync. I know the test for inByte > -1 is filtering out the FF but if I don't have that test I get a continuous stream of FF.
  
  

  CON
  
    _CLKMODE = XTAL1 + PLL16X
    _CLKFREQ = 80_000_000
  
  
  OBJ
  
    
    pst              : "Parallax Serial Terminal"
    serial           : "FullDuplexSerial"             
  
  PUB Main | inByte, numBytes
  
    pst.start(921600)
    serial.start( 1, 2, 00, 9_600)
    repeat
      inByte := serial.rxTime(500)
      if inByte > -1
       
        pst.hex(inByte,2)
        pst.char(" ")
        numBytes += 1
        if numBytes == 5
         pst.char(13)
         numBytes := 0
      else
        if numBytes > 0
         numBytes := 0
         pst.char(13)
  
• JonnyMac Posts: 9,563

  2013-08-16 08:16 edited 2013-08-16 08:16

  Are you sure you can run PST that fast? If I'm not mistaken, it's foundation is FDS which will not reliably handle 921600 baud.
• OldFartRadioman Posts: 30

  2013-08-16 09:15 edited 2013-08-16 09:15

  I have been running it slower but had increased speed on the chance that it was contributing to missed charachers on the RX side. I am thinking at the moment my sync issues are related to the missing FF's.
• ErNa Posts: 1,842

  2013-08-16 09:46 edited 2013-08-16 09:46

  Hi, you are not missing FFh, The function returns a long, the character is the LSByte if your long InByte, -1 equals FF_FF_FF_FFh and so 0FFH is a positive number. I would also not run PST at this high speed, You will not have more than 4 times the number of output characters to pst then you read. So 100kBaud is sufficient.
• Duane Degn Posts: 10,588

  2013-08-16 10:16 edited 2013-08-16 10:16

  I don't think FDS deals with framing errors correctly.
  
  Tracy Allen's four port serial driver behaves much better. I've had projects where I had trouble receiving data (garbage data detected) with FDS but when I switched to Tracy's object the problems went away.
  
  Another plus to using Tracy's driver is you can use the same driver for display your debug information.