AVR1300Цитата
The internal temperature sensor is linear. Ideally the measured value at 0°K will
correspond to a “0” result from the ADC. An approximate linear line can be made from
the 0°K to the measured value in the production. This measured production value is
stored in the signature row and the value correspond to a measurement done at 85°C
(358°K) with an accuracy of +- 5°C. The inaccuracy will result in some offset when
measuring temperatures.
The measurement stored in the signature row is done in unsigned mode with 12-bit
resolution with the internal 1V reference. The ADC setup has to be the same if this
value is going to be used in the application. The stored value can be used for a 2-
point calibration where the second point will be 0°K and the ADC value will be 0.
The best way to get accurate results is to do a 2-point calibration to get the incline of
the curve. To do a 2-point calibration, select 2 temperatures where you can do the
measurements where the temperature is known and is accurate. Do a measurement
at both temperatures with the wanted setup of the ADC (mode, sample rate,
resolution). When you have these values, you can calculate the coefficient for the
curve and you can use this in you application. The formula below can be used to
calculate the temperature change per bit:
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Сообщение отредактировал Юрий_СВ - Jul 26 2011, 08:22
Температурный датчик ATxmega
Jul 26 2011, 06:53
