Shop OBEX P1 Docs P2 Docs Learn Events
Woah is me: SX28 Failure Snippit — Parallax Forums

Woah is me: SX28 Failure Snippit

YendorYendor Posts: 288
edited 2010-04-21 19:14 in General Discussion
Just a little personal story to share...

Well, here I was, having a couple hours and in the right frame of mind to do some coding on my project with my sx tech board.

Things weren't·working well... I tried some known working coded, and still no dice.

I notice that my status led...instead of turning on/off, it goes on, and dims.

Examined code, take off my aux breadboard, check for shorts, etc. nada.

Double checked my code, then eliminated everything except code for pulsing·the led.

Still... On/Dim...On/Dim.

Measureing the voltage 5V on, 2.5 Volts off - Man, wondering if·eletronics is really for me?· What's going on?

Turns out all the pin showed 2.5 volts!···

I was thinking I had some stray AC voltages from somewhere -·isolation proved nothing.· (In another related 'why me' story,·i was able to magically turn on an LED by touching·the wire instead of the·piezo film.· Turned out I had been placing my foot on my·KVM switch, which had·some sort of AC signal from it impacting the circuit.· That took a bit of time·to·figuring out!)

Well, lucky I had another sx28 and popped it in, and all worked great!

Not sure what happened.· Must've been some sort of static issue or something - i've never had that happen to me·before.· It always just stays on my desk.

What's facinating about this foir me, is that it only did it when it had a program uploaded, and the program (at least the led part)·essentially still worked, althoug it wasn't truely off. .·

I guess something happened in the output stage of the SX.

I guess I'll be ording a few more SX28's.in the near future!

So much for my time on this tonight.· Just thought I'd vent and see anyones thoughts.

Thanks for listening!




·

Comments

  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-04-21 13:57
    Those chips are usually pretty robust. How did you have the LED wired? Also, what programs are you using to develop and test in (SX/B, Assembly, etc) In the beginning part of your program are you setting the port (pin) as an output?

    Robert
  • YendorYendor Posts: 288
    edited 2010-04-21 19:14
    Hi Robert,

    Thanks for your post, and I agree.

    LED is essentially RB0 to a 330 ohm resistor to the LED to VSS (Gnd)

    I used SX/B, and the· I/O was set up in code·to be:

    LED Pin RB.0 Output



    Would have never thought it was the micro - esp. all pins!

    Hmm,· maybe I can now sell this chip as an April fool's gag!
Sign In or Register to comment.