How do you compare current time, without using Alarm

Using Arduino Programming Questions
1

I am using Arduino Uno and Ds1307 RTC time.

I am having RTC time running. I have variable like Hr_ontime , Min_ontime
Hr_offtime and Min_offtime

i would like to turnon the relay between Hr_ontime :min_time & Hr_offtime: min_offtime

#include "Wire.h"
#define DS1307_ADDRESS 0x68
byte zero = 0x00; //workaround for issue #527

void setup() {
  Wire.begin();
  Serial.begin(9600);
  setDateTime(); //MUST CONFIGURE IN FUNCTION
}

void loop() {
  printDate();
  delay(1000);
}

void setDateTime() {

  byte second =      45; //0-59
  byte minute =      12; //0-59
  byte hour =        4; //0-23
  byte weekDay =    2; //1-7
  byte monthDay =    22; //1-31
  byte month =       4; //1-12
  byte year  =       14; //0-99

  Wire.beginTransmission(DS1307_ADDRESS);
  Wire.write(zero); //stop Oscillator

  Wire.write(decToBcd(second));
  Wire.write(decToBcd(minute));
  Wire.write(decToBcd(hour));
  Wire.write(decToBcd(weekDay));
  Wire.write(decToBcd(monthDay));
  Wire.write(decToBcd(month));
  Wire.write(decToBcd(year));

  Wire.write(zero); //start

  Wire.endTransmission();

}

byte decToBcd(byte val) {
  // Convert normal decimal numbers to binary coded decimal
  return ( (val / 10 * 16) + (val % 10) );
}

byte bcdToDec(byte val)  {
  // Convert binary coded decimal to normal decimal numbers
  return ( (val / 16 * 10) + (val % 16) );
}

void printDate() {

  // Reset the register pointer
  Wire.beginTransmission(DS1307_ADDRESS);
  Wire.write(zero);
  Wire.endTransmission();

  Wire.requestFrom(DS1307_ADDRESS, 7);

  int second = bcdToDec(Wire.read());
  int minute = bcdToDec(Wire.read());
  int hour = bcdToDec(Wire.read() & 0b111111); //24 hour time
  int weekDay = bcdToDec(Wire.read()); //0-6 -> sunday - Saturday
  int monthDay = bcdToDec(Wire.read());
  int month = bcdToDec(Wire.read());
  int year = bcdToDec(Wire.read());

  //print the date EG   3/1/11 23:59:59
  Serial.print(monthDay);
  Serial.print("/");


  Serial.print(month);
  Serial.print("/");

  Serial.print(year);
  Serial.print(" ");
  Serial.print(hour);
  Serial.print(":");
  Serial.print(minute);
  Serial.print(":");
  Serial.println(second);

}
2

calculate minutesOfDay then compare in an if-condition

3

int a =0;

if (((a ==0) && (Hr_ontime == hour) && (Min_ontime == minute))) {
(turn relay on here)
a = 1;
}

if (((a ==1) && (Hr_offtime == hour) && (Min_offtime == minute))) {
(turn relay off here)
a = 0;
}

Or like StefanL38 said with calculating minutes of the day to replace checking hour and minute.

4

Your sample code doesn’t include any of the variables you mention and seems largely irrelevant to your question, other than accessing a RTC module.

However to answer your question directly, assuming an active LOW relay...

int time = hour * 60 + minute;
int onTime = Hr_ontime * 60 + min_time;
int offTime = Hr_offtime * 60 + min_offtime;
bool relayState = time >= onTime && time < offTime;
digitalWrite(relayPin, relayState ? LOW : HIGH);

This will work better than comparing equality of on and off times, since if you turn on the Arduino during the ON period, or adjust the on/off times while it is running, the relay will always be set correctly.

5