# Difference between revisions of "Lesson 15--Microduino "Make sense of warm cup circuit""

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 Language: English  • 中文

## Objective

Last lesson introduced how to use LM35D, this lesson will show you how to make a analog thermal cup combined with Microduino.

## Equipment

• Microduino-Core
• Microduino-FT232R
• Other hardware equipment
• Breadboard Jumper one box
• Breadboard one piece
• LM35D temperature sensor one
• RGB LED one
• 450Ω resistor one

## Experimental schematic

LM35's connection doesn't change, just add a common anode RGB LED.

## Program

```void setup() {
Serial.begin(115200);         //Set hte baud rate as 115200
for(int i=2;i<5;i++)          //Set LED output
{
pinMode(i, OUTPUT);
}
}

void loop() {

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

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

if (temp<21)  //Low temperature setting, and led display
{
digitalWrite(4, HIGH);
digitalWrite(3, HIGH);
digitalWrite(2, LOW);
}
else if (temp>=21 && temp<=23)  //Middle temperature setting, && means "and" operation
{
digitalWrite(4, HIGH);
digitalWrite(3, LOW);
digitalWrite(2, HIGH);
}
else if (temp>23)   //High temperature setting
{
digitalWrite(4, LOW);
digitalWrite(3, HIGH);
digitalWrite(2, HIGH);
}
Serial.println(temp); //Output the temperature from serial port
delay(1000);         //Wait for 1s and refresh the data
}```

## Result

The temperature is set to low temperature, middle temperature and high temperature three range. When the temperature in the low temperature zone, RGB display a green light, blue light display in the middle temperature zone,and high temperature red light. Simulates a temperature sensing cup.