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Thread: Bad sensor?

  1. #1
    Constant Bitrate
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    Aug 2006
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    Bad sensor?

    Hello,

    I'm looking for some input as to whether I'm dumb or my sensor's busted.

    I created an instance using my Fusion Brain and just a temperature sensor. I finally got the configurator file working using just the Temperature sensor[celcius] function. When I read the value running the config file in MDX, I got temps around 40 C.

    I implanted the C->F converter parameters into the function and got temps around 120 F, also.

    Could I be using the standard functions wrong or do I have a busted sensor? (granted it is kinda old...)

    Thanks!
    CT

  2. #2
    Fusion Brain Creator 2k1Toaster's Avatar
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    Quote Originally Posted by ctsoccer13 View Post
    Hello,

    I'm looking for some input as to whether I'm dumb or my sensor's busted.

    I created an instance using my Fusion Brain and just a temperature sensor. I finally got the configurator file working using just the Temperature sensor[celcius] function. When I read the value running the config file in MDX, I got temps around 40 C.

    I implanted the C->F converter parameters into the function and got temps around 120 F, also.

    Could I be using the standard functions wrong or do I have a busted sensor? (granted it is kinda old...)

    Thanks!
    CT
    How old? If you ordered in early to mid 2007, you have a different temperature sensor, which will read high if used with the newer sensor's function. By any chance can you read the markings on the black part?
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

  3. #3
    Constant Bitrate
    Join Date
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    Ah, yea.. I did order it probably mid-last year.


    The ridiculously small writing on the back says something along the lines of:
    MCP
    9701AE
    TO
    8422EW

    Forgive me if I'm off by a letter or number--it's kinda hard to read

  4. #4
    Fusion Brain Creator
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    if you can, probe the sensor with a multimeter while it's being powered. Let us knwo what voltage it reports, and what temperature.

  5. #5
    Constant Bitrate
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    hey, sorry it took me a while to respond--had a bit going on.

    I measured the voltage across it and its at 3.618 V while reading a temp of 41.58 C using the temperature function given with the configurator.

    Thanks for the help so far!
    CT

  6. #6
    Fusion Brain Creator
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    vout=.0195*temp+.4, where temp is measured in degC.

    so, (3.61800 - .400) / .0195 = 165.025641

    which doesn't make any sense. I think you're measuring it wrong. Measure between the two black wires, not the red one.

  7. #7
    Constant Bitrate
    Join Date
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    my mistake. i was measuring Vce, rather than Vbe.

    Vbe = .945 V
    T = 42.33 Celc.

    Plugging the numbers in, it makes sense that the calculated T would be around 27-28 degrees C. So would the fix be as easy as multiplying the temperature calculated by the given function by a factor of .66?

    Sorry for the mixup...

    CT

  8. #8
    Fusion Brain Creator
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    Interesting. There was a bug in the firmware. Can you use the brain to measure a known voltage source, like a 1.5 volt battery, and report back?

    Additionally, let us know what the brain measures the voltage as, without any temperature functions. You can use the virtual brain function for this, I think.

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