This is a little gadget I made to cool off the different media systems that are contained inside entertainment systems. I used and Uno R3, LM35 temp. sensor, indicator LED, and a servo. What happens is that the temp sensor monitors the temperature inside the cabinet that contains the media system and when the temperature inside the cabinet reaches a predetermined temp, the servo will activate causing the cabinet door to become ajar to facilitate better air flow, the indicator light comes on to tell you that the cabinet is to hot and that is has opened the door to give better air flow, and then a fan mounted inside the cabinet will also turn on to further facilitate air flow and cool the cabinet back to a safe level. When the temperature reaches a safe temp again, the fan and light will shut off and the servo will close the door. Here is the cade for the project as well as a tutorial about it I have posted on my Youtube page.
Link to tutorial:
Code:
#include <Servo.h> // Servo header file is needed to control the servo motor.
Servo servo1; // Create servo object to allow us to control the servo motor.
float tempC; // create variable to store the temperature in.
int tempPin = 0; // Attach vout to analog pin 0.
int led = 13; // attach led to pin 13.
int fan1 = 3; // attach base of transistor to digital pin 3.
int pos = 0; // create variable to store the position of the servo motor.
void setup() // Will execute once at the start of the code.
{
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
pinMode (led, OUTPUT); // sets the led pin 13 up as an output.
pinMode (fan1, OUTPUT); // sets the fan1 pin 3 up as an output.
servo1.attach(5); // attaches the servo motor to digital pin 5.
}
void loop() // code here will continue to replay nutil powered off.
{
tempC = analogRead(tempPin); // read the analog value from the lm35 sensor.
tempC = (5.0 * tempC * 100.0)/1024.0; // convert the analog input to temperature in centigrade.
Serial.print((byte)tempC); // send the data to the computer.
if (tempC > 24) // creates bool expression for analyzation. if it evaluates to true,
{ // the body of the if statement will execute.
pos = 180; // sets pos equal to 180.
digitalWrite (led, HIGH); // turns on led.
digitalWrite (fan1, HIGH); // turns on fan1.
servo1.write(pos); // turns servo to 180 degrees.
}
else // if the if equation evaluates to false the else statement will execute.
{
pos = 90; // sets pos equal to 90.
digitalWrite (led, LOW); // turns off led.
digitalWrite (fan1, LOW); // turns off fan1.
servo1.write(pos); // turns servo to 90 degrees.
}
delay(3000); // wait 3 seconds before redoing the loop.
}