Shop OBEX P1 Docs P2 Docs Learn Events
SX-Key no longer working... replaec with SX-Blitz? — Parallax Forums

SX-Key no longer working... replaec with SX-Blitz?

ClintClint Posts: 95
edited 2010-01-04 17:49 in General Discussion
My SX-key seems to have stopped working mysteriously (I get a "SX-key not found on com#"). I have been using it for several weeks programming SXs with the same program every time and it has worked fine up until today. I have tried things like restarting my computer, reinstalling the Parallax USB-to-serial drivers, installed the latest version of the SX-Key editor, tried programming different SXs with different boards and power supplies... no luck. I'm thinking my SX-key is probably just bad for one reason or another and it's time for a replacement.

Since I am just using the same program over and over, will the SX-blitz work for me? Reading on the Parallax website it seems like it will work fine for programming SXs, it just lacks some debugging capabilities which I don't use anyway.

I'm also curious what sorts of things might have caused my SX-Key to stop working. The board I am connecting it to during programming is powered by batteries through a 5v LDO regulator. There is a 50mHz oscillator connected to the SX on the board and I'm wondering if it's okay to have that connected while programming (I read somewhere that it was okay). What about a loose connection between the header and the SX-key? I've noticed sometimes I would get a chip connection error and I could get it to program after "jiggling" the SX-key on the header.

Thanks for any help,
Clint

Comments

  • PJAllenPJAllen Banned Posts: 5,065
    edited 2010-01-01 00:28
    I had trouble with an SX_Blitz or so I thought.· It was my supply, just a bit marginal.

    Sounds like your connectivity is suspect.

    You cannot program with an oscillator in circuit, that's a no-no, that'll wreck your tool.· (A crystal is OK and a resonator is OK.)
  • ClintClint Posts: 95
    edited 2010-01-01 04:35
    Sorry, I wrote that incorrectly. I am using the 50mHz industrial resonator from Parallax (PN 250-05060). Is that okay to have in the circuit while programming?

    I have a 4pin header soldered to my PCB. It's a straight version of the 90 degree header that comes on the SX tech board. It should make an equivalent connection as the one on the SX Tech board.
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2010-01-01 05:33
    Resonators and crystals are okay to leave in during programming. TTL oscillators are not as they can not tolerate the 12.5v programming voltage. I had an old serial SX-Key go bad recently. I noticed occasionally it would just lock up and draw several hundred mA. Had I set the current limiting on my power supply correctly I might not have burned the key up.
  • ClintClint Posts: 95
    edited 2010-01-01 08:52
    I have Vdd to Vss at 5v during programming. Is that incorrect? Where does the 12.5v come in?
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2010-01-01 17:16
    The 12.5v is generated on the key/blitz and applied to OSC1 during programming. When you have a TTL oscillator connected to OSC1 at the same time it will not like the 12.5v and blow, likely taking the key/blitz with it. But since you're using crystals or resonators only, don't worry about it. It sound like a blitz is fine for your needs as long as you don't need in-circuit debugging or the variable clocking function of the key.
    Martin Hodge
    (Long Live the SX!.... aw Smile)
  • Ken GraceyKen Gracey Posts: 7,417
    edited 2010-01-01 20:16
    Clint, contact our tech support on Monday and we can get you a replacement.

    Viva la SX!

    Ken Gracey
  • WhitWhit Posts: 4,191
    edited 2010-01-01 23:34
    Congrats Clint! Parallax comes through again.

    Love the new look Ken - I saw it when you first posted it - sorry for the delayed comment.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Whit+


    "We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
  • ClintClint Posts: 95
    edited 2010-01-03 01:09
    Ken Gracey (Parallax) said...
    Clint, contact our tech support on Monday and we can get you a replacement.

    Viva la SX!

    Ken Gracey
    That is awesome. Thank you!
  • ClintClint Posts: 95
    edited 2010-01-03 23:53
    Shmoopy said...
    The 12.5v is generated on the key/blitz and applied to OSC1 during programming. When you have a TTL oscillator connected to OSC1 at the same time it will not like the 12.5v and blow, likely taking the key/blitz with it. But since you're using crystals or resonators only, don't worry about it. It sound like a blitz is fine for your needs as long as you don't need in-circuit debugging or the variable clocking function of the key.
    Martin Hodge
    (Long Live the SX!.... aw Smile)
    Thanks for the added info. Does the 12.5v get applied anywhere other than the OSC1 pin?
    I have I/O connected during programming so I just want to make sure I'm not hurting anything.
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2010-01-04 02:03
    Nope, just OSC1.
  • ClintClint Posts: 95
    edited 2010-01-04 17:49
    THANK YOU PARALLAX!

    This morning I talked to Josh in tech support and Chantal in sales. They were both very friendly and helpful. Unlike a lot of so-called tech support I've received with other companies, there was no anxiety or headache - just a friendly conversation between people trying to figure out a problem.

    Parallax is sending a replacement SX-Key free of charge and I bought an SX-Blitz for backup. I just want to say thank you for the great support!

    Post Edited (Clint) : 1/4/2010 11:36:51 PM GMT
Sign In or Register to comment.