LM35 temperature sensor circuit

Based on the characteristics of the legs on the IC LM35, then we will use the circuit so that the circuit portion below, can only measure the temperature of 2 to 150 degrees Celsius. How to put them together, namely:

LM35 temperature sensor circuit

1. Connect the foot 1 to VCC
2. Connect the second leg (middle) to A0. A0 is the analog pins, foot pin analog functions for a variety of transducers / sensors that require analog signals. Therefore, to read this leg using analogRead (), while for writing it using analogWrite ().
3. Connect foot-3 to GND.

The characteristics of this sensor is that every increase of 10 mV at the output leg, marking an increase of 1o Celsius temperature. Thus, because Networks 5.1 is only capable of measuring from 2o Celsius, the minimum LM35 output is 20 mV and 1500 mV maximum. LM35 temperature conversion on output also depends on the reference voltage used.

Arduino reference voltage at three (special Arduino Uno) 7, the default reference voltage, internal, and external. If we do not define the reference voltage that will be used, the Arduino will default to using a reference voltage of 5 volts. In addition to 5 volts, the voltage supplied by arduino default is 3.3 volts. However, we must make a jumper from 3.3 volts (in the Arduino board) to the AREF pin, and then execute the command analogReference (DEFAULT).

Arduino internal reference voltage is 1.1 volts, to use a voltage reference, we shall give orders analogReference (INTERNAL).

But if you want to use a reference voltage other than 5, 3.3, dan1.1 volts, we can use an external reference voltage. This reference voltage must be between 0 and 5 volts, if not, they can be damaged Arduino. If we use this custom reference voltage, then we must put a voltage source and the AREF to give orders analogReference (EXTERNAL);

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