79 lines
2.1 KiB
C++
79 lines
2.1 KiB
C++
// Written 2015 by Johannes Findeisen <you@hanez.org>
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#include <LiquidCrystal.h>
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// Initialize the LCD code. Take care of the pins I use. The first two pins
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// are 12 and 11 in most examples around the web. I use pin 7 and 6 because of
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// nicer wiring on my breadboard.
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// Read this for more information:
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// https://www.arduino.cc/en/Tutorial/LiquidCrystal
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LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
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// Define how many samples should be collected every $collectDelay miliseconds.
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// After sample collection the temperature is beeing calculated and then
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// send to the LCD.
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int samples = 30;
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// Collect delay between each sample.
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int collectDelay = 2000;
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// The pin where the status LED is connected to.
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int ledPin = 13;
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// The analog input pin where the LM35 is connected to.
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int tempPin = 0;
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// Just some variable initializations
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float tempC = 0;
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float tempClast = 0;
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float tempF = 0;
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void setup() {
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pinMode(ledPin, OUTPUT);
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lcd.begin(16, 2);
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lcd.print("Temperature:");
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lcd.setCursor(0, 1);
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tempC = (5.0 * analogRead(tempPin) * 100.0) / 1024.0;
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tempF = (tempC * 9) / 5 + 32;
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lcd_print();
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}
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// Prints results to the display
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void lcd_print() {
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lcd.setCursor(0, 1);
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lcd.print(tempC);
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lcd.print((char)223);
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lcd.print("C/");
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lcd.print(tempF);
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lcd.print((char)223);
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lcd.print("F");
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if(tempClast > tempC) {
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lcd.print("-");
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} else if(tempClast < tempC) {
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lcd.print("+");
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} else {
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lcd.print("*");
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}
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}
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void loop() {
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int i;
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tempC = 0;
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for(i = 0; i <= (samples - 1); i++) {
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// Read this to understand the temperature calculation:
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// http://www.danielandrade.net/2008/07/05/temperature-sensor-arduino/
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tempC = tempC + ((5.0 * analogRead(tempPin) * 100.0) / 1024.0);
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digitalWrite(ledPin, HIGH);
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delay((collectDelay / 2));
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digitalWrite(ledPin, LOW);
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delay((collectDelay / 2));
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}
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// Calculate temperature
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tempC = tempC / (float)samples;
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// Celsius to Fahrenheit cobversation
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tempF = (tempC * 9) / 5 + 32;
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// Print result to the display
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lcd_print();
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// Remember current temperature for next run
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tempClast = tempC;
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}
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