I have 2 relay setup and an LCD screen to display the pin status of the relay which is controlled by a temperature/humidity sensor.
When the relay switches (i believe when it switches off) the LCD screen some times displays partial gobbledygook & some times goes completely blank (back light stays on)
Does any one have any idea why this might happen?
#include <LiquidCrystal.h>
#include "DHT.h"
#define DHTPIN 6
#define DHTTYPE DHT22
#define heaterpin 8
#define fanpin 9
#define humpin 10
#define arrsize 40
DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
float h;
float t;
int avgTemp;
int avgHum;
int timespass = 360;
int tempArr[arrsize];
int humArr[arrsize];
int arrFill;
int hum;
int temp;
void setup() {
Serial.begin(9600);
dht.begin(); /// start temp sensor etc
pinMode(heaterpin, OUTPUT);
pinMode(fanpin, OUTPUT);
pinMode(humpin, OUTPUT);
lcd.begin(16, 2);
}
void loop() {
h = dht.readHumidity();
t = dht.readTemperature();
hum = h;
temp = t;
checkHumidity(hum);
checkTemp(temp);
writeToArray();
doAverages();
writeToLCD();
delay(5000);
}
void writeToArray(){
timespass = timespass + 1;
if(timespass > 360){ //720
arrFill = arrFill + 1;
if(arrFill == arrsize){
arrFill = 1;
}
humArr[arrFill] = hum;
tempArr[arrFill] = temp;
timespass = 0;
}
}
void doAverages(){
avgTemp = 0;
avgHum = 0;
for(int x = 0; x <= arrFill; x = x + 1){
avgTemp = avgTemp + tempArr[x];
avgHum = avgHum + humArr[x];
}
avgTemp = avgTemp / arrFill;
avgHum = avgHum / arrFill;
}
void writeToLCD(){
lcd.setCursor(0, 1);
if(digitalRead(heaterpin) == LOW){
lcd.print("T:On");
}else{
lcd.print("T:Off");
}
if(digitalRead(humpin) == LOW){
lcd.print(" H:On");
}else{
lcd.print(" H:Off");
}
if(digitalRead(fanpin) ==LOW){
lcd.print(" F:Off");
}else{
lcd.print(" F:On");
}
lcd.setCursor(0, 0);
lcd.print(temp);
lcd.print("c");
lcd.print(" ");
lcd.print(hum);
lcd.print("% ");
lcd.print(avgTemp);
lcd.print("c");
lcd.print(" ");
lcd.print(avgHum);
lcd.print("%");
}
void checkHumidity(int hum1){
if(hum1 < 90){
digitalWrite(humpin,LOW);
//digitalWrite(fanpin,LOW);
}else if(hum1 > 90){
digitalWrite(humpin,HIGH);
//digitalWrite(fanpin,HIGH);
}
}
void checkTemp(int temp1){
if(temp1 < 24){
digitalWrite(heaterpin,LOW);
}else if(temp1 > 27){
digitalWrite(heaterpin,HIGH);
}
}
