Arduino-uno sketch not working properly after power gone - arduino

Question

I'm relatively new to Arduino, and here are what I was trying to do.
I want to control a relay circuit using IR(InfarRet) remote. Here is the code what I'm using :
#include <IRremote.h>
int RECV_PIN = 6;
IRrecv irrecv(RECV_PIN);
decode_results results;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
irrecv.enableIRIn();
pinMode (5 ,OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
if (irrecv.decode(&results)){
Serial.println(results.value,DEC);
irrecv.resume();
switch (results.value){
case 3150073167:
digitalWrite(5,HIGH);
break;
case 68850955:
digitalWrite (5,LOW);
break;
}
}
}
circuit is working properly,
but after power restart it is not working properly, hear is a snap :
Error :
how to fix this error ?

Answer 1

Usually, a controller is meant to run forever ("24/7").
In the rare case of a restart, the whole system should be set to a defined initial safe state. (That should usually be the same as during power off)
How come your relay remains ON while the arduino is OFF?
If you really want to store a previous state, EEPROM is a good place.
(Fully agree with KIIV)

Answer 2

RAM is volatile memory, and after power loss it is lost too (IO Ports are reset to INPUT mode without pull-ups).
You can use EEPROM to store last state and restore it in setup() function.
For AVR based arduinos something like this can be used:
#include <EEPROM.h>
#include <IRremote.h>
const int RELAY_PIN = 5;
const int RECV_PIN = 6;
const int address = 0;
byte state = 0;
decode_results results;
IRrecv irrecv(RECV_PIN);
void setup() {
Serial.begin(9600);
irrecv.enableIRIn();
state = EEPROM.read(address);
pinMode (RELAY_PIN, OUTPUT);
digitalWrite(RELAY_PIN, state);
}
void loop() {
if (irrecv.decode(&results)) {
Serial.println(results.value,DEC);
irrecv.resume();
switch (results.value){
case 3150073167LU:
if (state == LOW) {
state = HIGH;
EEPROM.write(address, state);
}
break;
case 68850955LU:
if (state == HIGH) {
state = LOW;
EEPROM.write(address, state);
}
break;
default:
break;
}
digitalWrite(RELAY_PIN, state);
}
}