LM35 Temperature Interfacing with micro-controller

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Introduction:

LM35 is most commonly used temperature sensor in most of the projects. It calibrated directly in Celsius. Linear +10mV/ Degree Celsius. Sensor has 0.5 Degree Celsius accuracy. Range is -55 to 150 degree Celsius.

Datasheet is available on link https://www.ti.com/lit/ds/symlink/lm35.pdf .


Formula for ADC :

The formula for VOUT is given as:
VOUT(mV) = 10mV/°C * T
Using the above formula, with VREF in Volts and Scale-factor in V/°C, we can compute the temperature(T) from 10-bit ADC Result as:
T = (ADC_RESULT * VREF)/(1024 * 0.01) °C
Which can be simplified as,
T = (ADC_RESULT * VREF * 100)/1024 °C
So, when using VREF = 3.3V we get,
T = (ADC_RESULT * 330)/1024 °C

Interfacing Image with micro-controller:

Additional Tips:

The LM61 sensor is more convenient to use for measuring negative temperatures. Unlike LM35 (which has zero DC offset), the LM61 sensor has a DC offset of 600 mV, which allows reading negative temperatures without the need for a negative supply.


More info of other temperature sensor will updated soon.Please comment for more information….