I2C write - value too big


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  1. #1


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    Well, i think i just fixed one problem and found a new one

    I have sucessfuly use the code " I2CREAD SDA,SCL,CTW,ADDR,[tempe] ".

    After several changes i tryed Mister-e's suggestion and removed the OSCTUNE=0 line.

    It doesnt make sense to me ( or does it ? ), but it's working this way now.

    The new problem that i found is that while debugging i found out that the problem related with getting low values passed the 120'ich mark IS NOT related with the eeprom/low-highbytes.

    I got a variable resistor to simulate the LM35 and was changing the value while recording, and i could see that the value captured dropped after the conversion and before recording to the eeprom.

    this is the capture while increasing the variable resistor
    Code:
    111,3
    111,3
    111,8
    112,3
    112,3
    112,7
    112,7
    113,2
    113,7
    114,2
    114,7
    115,2
    115,7
    116,2
    117,6
    118,1
    118,6
    118,6
    118,6
    118,6
    119,1
    121
    121,5
    122
    122,5
    122,5
    122,5
    122,5
    0,4
    0,9
    0,4
    0,9
    0,4
    0,9
    0,4
    0,9
    0,4
    0,9
    now i'm lost

    .
    Last edited by ruijc; - 6th April 2008 at 12:37.

  2. #2
    Join Date
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    Hi, Ruicj

    Can you tell us how you get those values :

    ( 122.5 is NOT a PbP value ...)

    - Input value range ( volts ? ) / ref voltage
    - Math used ( in PbP )
    - Values you want to to output

    It's "not so clear" ...

    Alain

    PS : ANSEL doesn't match the ADCIN PORT !!! Check it !!!
    Last edited by Acetronics2; - 6th April 2008 at 12:51.
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
    ************************************************** ***********************
    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
    *****************************************

  3. #3


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    Hello Acetronics,

    these values i get from:

    Code:
    FOR ADDR=st TO ed
         
       		adcin temp,va
     
    tempe=(va*/5000 )>>2
    
            toggle red
            toggle green
            pause   418    ' calibration to get  1200  readings  ( 2 per second ) in 10 minutes   - 
            debug " recorded value: ", dec tempe," position  ", dec ADDR, 13,10
    the debug line gave these values after the adcin conversion.
    I'm colecting the voltage directly from the variable resistor which is simulating the voltage from a LM35 ( 0,2v - 1,5V )
    I'm not using any reference value, just VDD and VSS( i know...it's lame...but i'm not looking for the best resolution for now )

    .

  4. #4
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    seen it ???

    : ANSEL doesn't match the ADCIN PORT !!! Check it !!!

    ANSEL select A1 and A2
    ADCIN select A0 ...

    Alain
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
    ************************************************** ***********************
    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
    *****************************************

  5. #5


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    Acetronics,

    You are right !!! Thank you ( and the rest of the guys for the help )

    This was set when i was playing with several sensors

    But how can it be ?? If i have the ANSEL with a different channel, how can i get values on channel A0 ??

    This is why i didnt see it

  6. #6
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    May 2004
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    Wink

    Capacitive coupling ... pins are side-by-side !!!
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
    ************************************************** ***********************
    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
    *****************************************

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