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new propeller starter kit

haimhaim Posts: 25
edited 2007-09-25 13:32 in Propeller 1
Hi all,

I have got my propeller starter kit two weeks ago. Finally, I have time to test it out. I ran some test sample code and found the out put LED's would turned on as pairs.· (Such as I just turn on the P18 nothing else,·when the P18 turned on and P19 turned on also, but it was dimmer than P18.) Likewise, if I turned on the P19 and P18 turned on with half the brightness as P18. P20 and P21, P22 and P23 are the same as I discripted as P18 and P19. P16 and P17 worked fine. Do I have a leaky Propeller chip? Please advise. Thanks.

Hai

Comments

  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2007-09-25 01:47
    I believe the effect you are seeing is caused by the resistors that make up the VGA connection.

    Take a look at www.parallax.com/dl/docs/prod/prop/PropDemoDschem.pdf

    You'll find that some of the lines you mentioned are connected with resistors between.

    Oldbitcollector

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Buttons . . . check. Dials . . . check. Switches . . . check. Little colored lights . . . check.

    — Calvin, of 'Calvin and Hobbes.
  • deSilvadeSilva Posts: 2,967
    edited 2007-09-25 01:52
    Correct!
  • IAN STROMEIAN STROME Posts: 49
    edited 2007-09-25 01:54
    Hi Haim,
    Don't know this for sure,as built mine from scratch,but you've got the
    VGA resistor divisor on these pins,hence the slightly glowing LED

    Regards :- Ian

    :- In Scotland we have a word for Sushi :- Bait
  • parts-man73parts-man73 Posts: 830
    edited 2007-09-25 02:42
    Here's an Excerpt from a similar conversation back in April
    Somebody said...
    LEd 19 lights up but 18 also lights up at about half the intensity.

    This is true as I change all the way up to pin 23? The adjacent LED also lights up.

    Could it be possible there is some leakage or perhaps I have a defective Demo-Board? Or is it something I'm doing or not doing?
    Parts-man73 said...
    I remember someone once saying that you can prevent the other LED in the pair from lighting if you drive that output low. I don't have a demoboard to verify that, could someone else chime in if this is correct (or incorrect)??
    Paul Baker said...
    It's true, active driving the adjacent LED will make the co-lighting go away.
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    Brian

    uController.com - home of SpinStudio
  • haimhaim Posts: 25
    edited 2007-09-25 13:32
    Thanks. The informations are helpful.



    Best Regards to you all



    Hai
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