Heater for small fish bowl

Forum 2005-2010 (read only) General Exhibition
5

worked out the * display bit for when the heater is on :slight_smile:

updated code bellow:

/*

Will start and stop a peltier device in a pad under a fish bowl
depending on what the value of the thermsistor returns from
the water temprature and then display a status message 
onto the LCD (2x16) 
 
 The circuit:
 * LCD 1 GND
 * LCD 2 VCC
 * LCD 4 RS pin to digital pin 12
 * LCD 6 Enable pin to digital pin 11
 * LCD 11 D4 pin to digital pin 5
 * LCD 12 D5 pin to digital pin 4
 * LCD 13 D6 pin to digital pin 3
 * LCD 14 D7 pin to digital pin 2
 * LCD 3 VO pin to GND
 * LCD 15 + LED
 * LCD 16 - LED
 
 * Thermsistor to +5 and A0 and A0 resistor to gnd
 * LED D13
 * Heatpump D10
 
 LCD Library and code borrowed from:
  http://www.arduino.cc/en/Tutorial/LiquidCrystal
 */

// include LCD library
#include <LiquidCrystal.h>

// initialize pins and initial value
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int sensorPin = 0;
int ledPin = 9;
int heatPin = 10;
int sensorValue = 0;
int state = 0;

void setup() {
  // set up the LCD, and pins 
  lcd.begin(16, 2);
  pinMode(ledPin,OUTPUT);
  pinMode(heatPin,OUTPUT);
  //Blink to show startup
  digitalWrite(ledPin, HIGH);
  digitalWrite(heatPin, LOW);
  delay(35);
  digitalWrite(ledPin, LOW);
  
  
}

void loop() {
  lcd.setCursor(2, 0);
  lcd.print("FishFishHeat");
  lcd.setCursor(13, 1);
  lcd.print(sensorValue);
 sense(); // sensor input
 if (sensorValue <= 85){
   heatOn(); // start heatpump
 }

 else {
    lcd.setCursor(5, 1);
    lcd.print("is OK");
 }
 
 if (sensorValue >= 92) {
   heatOff(); // stop heatpump
 }
  // Turn on the display:
  lcd.display();
  delay(125);
  lcd.clear();
  
 if (state == 1){
  lcd.setCursor(0, 0);
  lcd.print("*");
  lcd.setCursor(15, 0);
  lcd.print("*");
 } 
}

void sense() { // sensor input
  sensorValue = analogRead(sensorPin);
  state = digitalRead(ledPin);
}

void heatOn() { // start heatpump
   digitalWrite(ledPin, HIGH);
   digitalWrite(heatPin, HIGH);
   lcd.setCursor(1, 1);
   lcd.print("is Low Temp");
}

void heatOff() { // stop heatpump
   digitalWrite(ledPin, LOW);
   digitalWrite(heatPin, LOW);
   lcd.setCursor(1, 1);
   lcd.print("is Hi Temp");
}

am about to test with heatpad attached will grab pics of the setup :wink: