Shop OBEX P1 Docs P2 Docs Learn Events
Java resets propeller — Parallax Forums

Java resets propeller

TrezitorulTrezitorul Posts: 68
edited 2010-07-28 01:33 in Propeller 1
I am writing a usb interface to the prop using java. However, when java opens the port on the propeller this causes the propeller to perform a hard reset. Any ideas on why that is?

Thanks,

Trezitorul

Comments

  • KyeKye Posts: 2,200
    edited 2010-07-27 11:47
    The serial port DTR line is toggled when the port is opened. The DTR line is attached to the reset pin of the propeller chip for programming.

    So, you need to prevent the program from toggling the DTR line.



    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Nyamekye,
  • TrezitorulTrezitorul Posts: 68
    edited 2010-07-27 23:20
    That did it. Thanks for the reply

    Sincerely,

    Trezitorul
  • BigFootBigFoot Posts: 259
    edited 2010-07-28 01:33
    There is another way that will fix the problem for newer PC's. Kye is correct, we had to either put shunts or a dip switches in the RTS line
    to keep our systems from resetting all the time.

    The problem is caused by the FTDI chip, they swear the Rts output is exactly like a PC serial port but if you have ever looked at both signals
    on a scope you will see that the FTDI chip puts out Rts pulses all the time, every time you plug in a another USB device and it puts out a
    bunch of them.

    There are some configuration variables for the chip that you can set from the PC side that will help with the resetting problem.

    Go into, Computer, Properties, Hardware, Device Manager, Ports (Com & Lpt) then find the Usb Serial Port for the device.
    Select that port then go into Port Settings, Advanced and un-check Serial Enumerator then check Disable modem Ctrl At Startup.

    This will not effect the prop plug or Propeller tool operation.

    If you really want to get creative you can edit there .Ini file.
Sign In or Register to comment.