How do I prevent the propellor from restarting when a serial program closes?

I'm using ubuntu. Is there a way to prevent that by, changing something on the propeller or on the program settings?

Comments

  • 13 Comments sorted by Date Added Votes
  • Is the serial connection through the propellers usb port?
    If so have you tried making it on different pins?
    Any com port in a storm
  • How are you connecting the propeller to your computer? Usb?

    And what's the circuit... Custom or Parallax board?

  • I'm using an activity board and I'm connected via usb.
  • The problem is likely to be that your Ubuntu serial program signals DTR when it closes. This is what resets the Prop. Can you configure the serial program not to do this? If there's a "no handshaking" option, selecting it may be all you need to do.

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • As an addendum to the above, you can reprogram the USB chip on the Activity Board not to send the DTR to its port pin that controls /RST. But in order to reprogram the Prop, you'll have to switch it back.

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • Or you need to cut the traces from usb to /reset and put a jumper there. Something that is missing on most parallax boards.

    Sadly,

    Mike
    I am just another Code Monkey.
    A determined coder can write COBOL programs in any language. -- Author unknown.
    Press any key to continue, any other key to quit

    The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this post are to be interpreted as described in RFC 2119.
  • I solved my problem
  • brandan wrote:
    I solved my problem
    Ok, how? One of the benefits of this community is sharing not only problems, but solutions.

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • I turned off DTR
  • For anyone wondering how to do it via command line:
    stty -F /dev/$DEVICE $BAUD -hup cbreak
    
    seems to do the trick. The `-hup` disables DTR when the last program on the serial port closes, and the `cbreak` makes it not EOF whenever there's nothing in the PC's receive buffer. This makes it possible to use `cat` and friends to operate on the serial port directly without needing a serial port program.
  • @brandan

    In your icon, green varies vertically and red varies horizontally. How is blue calculated?

    Oops! Didn't mean to highjack the thread; the devil made me do it.
    Re-inventing the wheel is not a waste of time if, when you are done, you understand why it is round.
    Cool, CA, USA 95614
  • mikeologistmikeologist Posts: 69
    edited December 3 Vote Up0Vote Down
    .
    Any com port in a storm
  • Beau SchwabeBeau Schwabe Posts: 6,308
    edited December 3 Vote Up0Vote Down
    You must have RevA ... I think RevB and RevC attempt to correct the problem with U14 and U15. This problem existed several years ago when I worked at Parallax and there was a software fix by forcing the TX line from the Propeller HIGH or LOW... I can't remember which... what is happening is that without power, the FTDI defaults to a mode that resets the Propeller. By forcing the TX line from the Propeller HIGH (<- I think that is correct)... the FTDI has enough parasitic power to prevent a reset.


    EDIT: Hmmm... I just noticed in the schematic that the enable for U14 and U15 buffer is not connected to anything or is a no-connect ... it should be connected to the +3.3V from the USB power to enable it when USB power is applied. ... it's possible it has an internal pullup however



    RevA:
    RevA.png

    RevB,C
    RevB_C.png



    Beau Schwabe -- Submicron Forensic Engineer
    www.Kit-Start.com - bschwabe@Kit-Start.com ෴෴ www.BScircuitDesigns.com - icbeau@bscircuitdesigns.com ෴෴

    Seriously at this point in the game the ship has sailed and "I have no expectations" <- said someone we know
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