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loosing voltage on rb — Parallax Forums

loosing voltage on rb

nick bernardnick bernard Posts: 329
edited 2005-05-30 13:24 in General Discussion
hi guys,
for some reason unknown to me rb.4,5,6 drop to 4v with a 100k load, 2.5v with a 10k load.
ra.2,3(inputs) & rb.3,4(outputs) are the only io pins used in my application. the other 4 pins work fine and illuminate my led w/10k resistor just fine.

since rb.012567 have no pcb connection what might be causing this fault on pins with no pcb connection?

btw i tried 2 different sx28's

my code:
;================Device======================================================================================
device sx18l,oschs3
device turbo, stackx, optionx
IRC_CAL IRC_SLOW
reset start_point
freq 20_000_000

;================Start=======================================================================================
org 0
start_point

mov !rb,#$00 ; Set port B as outputs

;================Program Go!=================================================================================
main
mov rb,#$FF
go
jmp go

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Byte walks into a bar and orders a pint. Bartender asks him "What's wrong?" Byte says "Parity error." Bartender nods and says "Yeah, I thought you looked a bit off."

Comments

  • BeanBean Posts: 8,129
    edited 2005-05-27 18:52
    Try using the "MODE $0F" before your "mov !rb" instruction.
    It sounds like it's setting the pull-ups instead of direction.
    Bean.

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    ·
  • nick bernardnick bernard Posts: 329
    edited 2005-05-30 13:24
    thanks bean

    i found the problem....

    nick said - "btw i tried 2 different sx28's"
    code said - device sx18l,oschs3

    i changed it to device sx28l,oschs3
    and it works fine
    i didnt realize that the line was so sensitive, shame on me

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Byte walks into a bar and orders a pint. Bartender asks him "What's wrong?"
    Byte says "Parity error." Bartender nods and says "Yeah, I thought you looked a bit off."

    Post Edited (nick bernard) : 5/30/2005 3:33:41 PM GMT
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