Lesson 14--Microduino "A simple thermometer"

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Objective

This lesson will introduce the temperature sensor, combined with Microduino to be a simple thermometer. Digital temperature sensors have a common DS18b20, DHT11, SHT10 and so one. Analog temperature sensor has thermistor, AD590, LM35D so on.

Equipment

LM35 temperature sensor

This sensor can measure of 0-100 degrees Celsius temperature, and output the value of voltage. Starting from 0 degrees temperature rise per 1 degree output voltage will increase 10 mv, so that we can use the analog port to detection sensor voltage, after simple to calculate the measured temperature value.

LM35 connection

Lesson14-LM35.jpg

Experimental schematic

The connection is very easy,just pay attention to the positive and negative。

Lesson14-schematic.jpg

Program

void setup() {
 
  Serial.begin(115200);       //Set teh baud rate to 115200
}

void loop() {

  int n = analogRead(A0);    //Read the voltage from A0

  float vol = n * (5.0 / 1023.0*100);   //Use a float variable to save temperature value which was calculated from voltage.

  Serial.println(vol);                   //Output the temperature from serial

  delay(1000);                           //Wait for 1s for refresh
}

Result

After download, you can see the temperature data from serial monitor, refreshed every 1s.

Lesson14.jpg

Video

https://www.youtube.com/watch?v=Yo3pF0iPbWk