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PST Characters — Parallax Forums

PST Characters

LarryCardoLarryCardo Posts: 28
edited 2011-02-22 13:40 in Propeller 1
I am trying to use the Parallax Serial Terminal--and getting strange characters.

Attached is the program that I think should produce lines of "testing".

Any suggestions.
picture of pst.jpg
823 x 740 - 145K

Comments

  • John AbshierJohn Abshier Posts: 1,116
    edited 2011-02-21 13:26
    You need to use a crystal. This is the most common setting
    CON
    _clkmode = xtal1 + pll16x
    _xinfreq = 5_000_000

    It says that the crystal is a 5MHz one with a PLL multiplier of 16 for 80 MHz operation

    John Abshier
  • LarryCardoLarryCardo Posts: 28
    edited 2011-02-21 14:11
    John,

    Thank you. It fixed everything!!!!!!!!!

    Larry
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2011-02-21 14:17
    Thinking out loud.

    You know, looking at that screenshot it almost looks like we could write an adaptation of PST that would run without the Crystal. Those look like consistent characters.

    OBC
  • MagIO2MagIO2 Posts: 2,243
    edited 2011-02-21 14:24
    Is it PST day today??? ;o)

    http://forums.parallax.com/showthread.php?129795-FullDuplexSerial-communication-problems

    Seems to be the same problem. And ... @Oldbit ... in one of the posts it's mentioned ... you simply have to compensate the deviation of the internal clock to the theoretical clock by starting the serial object with a different baudrate having the same deviation to the wished baudrate in opposite direction.
  • MicrocontrolledMicrocontrolled Posts: 2,461
    edited 2011-02-21 17:32
    A PST using the internal clock would be nice, seeing as I have 2 Propellers without a PLL....
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-02-22 08:46
    Microcontrolled,

    That's a good idea about having PST using the Prop's internal clock. You could enter a series of "U" characters or some other character with an easy to recognize bit pattern (ASCII "U" is %01010101). Once the pattern is recognized the Prop could change its baud to match the terminals baud.

    I don't know if I have time to do this today, but I'll put it on my todo list.

    This would be useful on battery operated devices that use the Prop's slow internal clock.

    Duane
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2011-02-22 09:03
    This should probably become a new thread, but I'll bet there is a LOT of things we could do with a Propeller running on internal clock that we haven't tried. Having a list of things that could be done with ONLY a Propeller. (No xtal, no EEPROM) would be interesting. An adjusted PST would be an excellent starting point.

    OBC
  • Cluso99Cluso99 Posts: 18,069
    edited 2011-02-22 13:40
    Nice: Yes, with a battery, after loading the program to hub ram, a timing on some characters sent by the pc could be done to calculate what the clock is actually and this could then be used to adjust your internal programs.
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