Category: Arduino

// include the library code:
#include <LiquidCrystal.h>
 
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int sensorPin = 0;
int sensorValue = 0;  // variable to store the value coming from the sensor
float voltage = 0;
float RH = 0;
 
void setup() {
  // set up the LCD's number of rows and columns:
  lcd.begin(16, 1);
}
 
void loop() {
  // read the value from the sensor:
  sensorValue = analogRead(sensorPin);
  // (1 = 0.0049V) 0-1023 range
  voltage = sensorValue * 0.0049;
  // Relative humidity(RH) (These are the values for my sensor, yours may differ a bit):
  // 0% = about 163
  // 100% = about 795
  // With roughly linear response.
  // 795 - 163 = 632 (points in the sensor's range)
  // 6.32 points = 1% RH
  RH = (sensorValue - 163) / 6.32;
  if (RH < -5) {
    lcd.setCursor(0,0);
    lcd.clear();
    lcd.print("Check sensor!");
  } else {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(sensorValue); //Analog input value in range of 0-1023
    lcd.setCursor(5, 0);
    lcd.print(voltage); //Voltage calculated from the previous value, see comment above
    lcd.setCursor(10, 0);
    lcd.print(RH); //Relative humidity in percent
  }
  delay(100);
}