Existem circuitos no site em:
Detetor nível água
São circuitos analógicos mas atualmente, o arduino ou o raspberry permitem outro tipo de controle.
#include <LiquidCrystal.h>
int ugnd=A0;
int quarter=A1;
int half=A2;
int threfrth=A3;
int full=A4;
int relay=8;
int buzzer=7;
int i; //relay status flag
int v=100; //comparison variable and give some adjustment for to get proper value
int b=0; //buzzerzer flag
int m=0; //relay flag
int c=0; //ugnd flag
int s;
int q;
int h;
int t;
int f;
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup()
{
pinMode(quarter,INPUT);
pinMode(half,INPUT);
pinMode(quarter,INPUT);
pinMode(full,INPUT);
pinMode(ugnd,INPUT);
pinMode(relay,OUTPUT);
pinMode(buzzer,OUTPUT);
lcd.begin(16, 2);
digitalWrite(buzzer,LOW);
}
void loop()
{
i=digitalRead(relay);
s=analogRead(ugnd);
q=analogRead(quarter);
h=analogRead(half);
t=analogRead(threfrth);
f=analogRead(full);
lcd.clear();
if(f>v && t>v && h>v && q>v ) //Statement to compare water levels from Arduino Analog pins
{
lcd.setCursor(0,0);
lcd.print(char(219));
lcd.print(char(219));
lcd.print(char(219));
lcd.print(char(219));
lcd.setCursor(5,0);
lcd.print("fullL");
m=0;
b=0;
}
else
{
if(f<v && t>v && h>v && q>v)//Statement to compare water levels from Arduino Analog pins
{
lcd.setCursor(0,0);
lcd.print(char(219));
lcd.print(char(219));
lcd.print(char(219));
lcd.print("_");
lcd.setCursor(5,0);
lcd.print("3/4th");
b=0;
}
else
{
if(f<v && t<v && h>v && q>v)//Statement to compare water levels from Arduino Analog pins
{
lcd.setCursor(0,0);
lcd.print(char(219));
lcd.print(char(219));
lcd.print("_");
lcd.print("_");
lcd.setCursor(5,0);
lcd.print("HALF");
m=1;
b=0;
}
else
if(f<v && t<v && h<v && q>v)//Statement to compare water levels from Arduino Analog pins
{
lcd.setCursor(0,0);
lcd.print(char(219));
lcd.print("_");
lcd.print("_");
lcd.print("_");
lcd.setCursor(5,0);
lcd.print("1/4th");
b=0;
}
else
{
if(f<v && t<v && h<v && q<v)//Statement to compare water levels from Arduino Analog pins
{
lcd.setCursor(0,0);
lcd.print("_");
lcd.print("_");
lcd.print("_");
lcd.print("_");
lcd.setCursor(5,0);
lcd.print("LOW");
b=0;
}
else
{
digitalWrite(relay,LOW);
lcd.setCursor(0,0);
lcd.print("ERROR!");
b=1;
}
}}}
if(i==HIGH)
{
lcd.setCursor(0,1);
lcd.print("relay ON");
}
else
{
lcd.setCursor(0,1);
lcd.print("relay OFF");
}
if(s>v && m==1)//Statement to compare water levels from Arduino Analog pins
{
digitalWrite(relay,HIGH);
}
if(s<v)
{
digitalWrite(relay,LOW);
lcd.setCursor(11,0);
lcd.print("Low");
lcd.setCursor(11,1);
lcd.print("ugnd");
c=1;
}
if(s>v)
{
c=0;
}
if(m==0)
{
digitalWrite(relay,LOW);
}
if(b==1 || c==1)//Statement to compare water levels from Arduino Analog pins
{
digitalWrite(buzzer,HIGH);
delay(500);
digitalWrite(buzzer,LOW);
}
else
{
digitalWrite(buzzer,LOW);
}
delay(100);
lcd.clear();
}
O display não tem de estar no circuito
Fonte circuito arduino:
www.theorycircuit.com/arduino-numeric-water-level-indicator-and-controller/