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Technical support / Re:Input scaling
« on: June 21, 2014, 04:26:58 AM »
Hi Guys
Im delighted i came across this in the forum I have been struggling with a similar problem, however reading your solutions really helped.
the problem i have now is i am not getting the expected value back from my adc.
the probe i am using is a -40 to +150 type
so using the same formula and I am assuming its between 16-20 degrees here....
my expected value at adc should be ((t+40)/190)*3277+819 = 1853 for 20 degrees and 1784 for 16 degrees
but i am only getting a value of 1504 at the adc.
I have checked and rechecked everything and the only thing i can find is the resistor is 248ohm instead of 250ohm and im not sure if this will affect my value.(reading via meter).
i am a complete beginner to all of this so sorry if this seems like a remedial problem!
Thanks in advance!
Ruaidhri
also where did you get the value of 2600?
Im delighted i came across this in the forum I have been struggling with a similar problem, however reading your solutions really helped.
the problem i have now is i am not getting the expected value back from my adc.
the probe i am using is a -40 to +150 type
so using the same formula and I am assuming its between 16-20 degrees here....
my expected value at adc should be ((t+40)/190)*3277+819 = 1853 for 20 degrees and 1784 for 16 degrees
but i am only getting a value of 1504 at the adc.
I have checked and rechecked everything and the only thing i can find is the resistor is 248ohm instead of 250ohm and im not sure if this will affect my value.(reading via meter).
i am a complete beginner to all of this so sorry if this seems like a remedial problem!
Thanks in advance!
Ruaidhri
also where did you get the value of 2600?