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Ways of checking logic level of BS2 output?? — Parallax Forums

Ways of checking logic level of BS2 output??

ArchiverArchiver Posts: 46,084
edited 2003-07-07 07:54 in General Discussion
Hi,
I need to check wif u pple on how to check e logic levels of a
BS2 o/p. Do I really need a logic probe?
The logic pen got a red and black connection. How do I power it up?




Blur

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-07-03 15:54
    Logic Pen: Red goes to +5, black goes to ground.

    You can check logic levels with a simple
    LED circuit -- put a 480 ohm resistor in
    series with the LED, then put it across
    the data pin and ground. If you 'know'
    the pin is high, and it doesn't light,
    you may have the LED backwards -- swap
    leads, and it should light.

    Make sure you use 'HIGH P0', or insure
    you set that pin to an output first.

    --- In basicstamps@yahoogroups.com, "barangsg" <barangsg@y...> wrote:
    > Hi,
    > I need to check wif u pple on how to check e logic levels of a
    > BS2 o/p. Do I really need a logic probe?
    > The logic pen got a red and black connection. How do I power it up?
    >
    >
    >
    >
    > Blur
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-04 07:36
    Beside what is already said, I recommend using a true logic probe
    (pen-style). I got one and it saved lots of trouble having a reliable
    instrument to verify logic levels. Furthermore, the probe I have also
    provides a tone signal which is very convenient when you have to look
    at anything else while measuring.

    Many people today belive that logic probes are outdated (well they
    may be not the right tool to check a 2GHz pentium), but I think this
    is not true. They are in fact a valuable tool when used properly, e.g
    with basic stamps.

    Regards
    Adrian
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-05 03:15
    Wat does yr probe look like at the connecting end?
    I've look around but only saw those tat hav a red n
    black plug jacks at the connecting end. Used them b4
    on those big troubleshooting board. How do I power
    them up w/o the big board? Eg. Red jack to +ve of BATT
    n Black to -ve of BATT? R there any types tat we
    insert batteries into them n operate?

    Thnks!


    --- Adrian Schneider <adrian.schneider@t...>
    wrote: > Beside what is already said, I recommend
    using a
    > true logic probe
    > (pen-style). I got one and it saved lots of trouble
    > having a reliable
    > instrument to verify logic levels. Furthermore, the
    > probe I have also
    > provides a tone signal which is very convenient when
    > you have to look
    > at anything else while measuring.
    >
    > Many people today belive that logic probes are
    > outdated (well they
    > may be not the right tool to check a 2GHz pentium),
    > but I think this
    > is not true. They are in fact a valuable tool when
    > used properly, e.g
    > with basic stamps.
    >
    > Regards
    > Adrian
    >
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2003-07-07 07:54
    Hello,

    my logic proble is one with two leads - a red micro clip (+V) and a
    black crocodile clip (GND) to power the probe. The probe usually
    needs 5V at least for TTL or more (up to some 15V for CMOS). This
    depends of the circuit under test. Batteries with sufficient supply
    voltage are expensive, big and heavy and it is usually easier to get
    the supply power from the circuit. Beside this you would need a
    ground connection anyway.

    Regards
    Adrian
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