'rtc' is not part of this scope

Using Arduino Programming Questions
#1

I am working on a larger remote monitoring project and I am adding a DS1307 to the MEGA2560 R3. I figured that I would start EASY and work the code into the big program, so I found some code on the forum from years ago. Needless to say with a few lines of code I hit a wall. I have looked at numerous FAQ’s and was unable to resolve the issue. I probably should change the hourly do something to a minute timed do something, for debugging.

Has to be some dumb mistake I made.

I have inserted the code and error message below.

#define DS1307_h
#include <TimeLib.h>
#include <DS1307RTC.h>
#include <RTClib.h>

void setup()
{
   now = rtc.now();
   previousHour = now.hour();
}

void loop()
{
   now = rtc.now();  // This is the line of code that is highlighted in the error message

   if ( now.hour() != previousHour )
   {
       previousHour = now.hour();
       DoSomethingEveryHour();
   }
}

void DoSomethingEveryHour()
   {
     Serial.println("Doing Something Now");
   {
   
}

ERROR msg:

Arduino: 1.8.9 (Windows Store 1.8.21.0) (Windows 10), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

C:\Users\Donald\Documents\Arduino\Time_-_DoingSomethingNow\Time_-_DoingSomethingNow.ino: In function 'void setup()':

Time_-_DoingSomethingNow:9:10: error: 'rtc' was not declared in this scope

    now = rtc.now();

          ^

Time_-_DoingSomethingNow:10:4: error: 'previousHour' was not declared in this scope

    previousHour = now.hour();

    ^

Time_-_DoingSomethingNow:10:23: error: request for member 'hour' in 'now', which is of non-class type 'time_t() {aka long unsigned int()}'

    previousHour = now.hour();

                       ^

C:\Users\Donald\Documents\Arduino\Time_-_DoingSomethingNow\Time_-_DoingSomethingNow.ino: In function 'void loop()':

Time_-_DoingSomethingNow:15:10: error: 'rtc' was not declared in this scope

    now = rtc.now();

          ^

Time_-_DoingSomethingNow:17:13: error: request for member 'hour' in 'now', which is of non-class type 'time_t() {aka long unsigned int()}'

    if ( now.hour() != previousHour )

             ^

Time_-_DoingSomethingNow:17:23: error: 'previousHour' was not declared in this scope

    if ( now.hour() != previousHour )

                       ^

Time_-_DoingSomethingNow:19:27: error: request for member 'hour' in 'now', which is of non-class type 'time_t() {aka long unsigned int()}'

        previousHour = now.hour();

                           ^

Time_-_DoingSomethingNow:20:29: error: 'doSomethingEveryHour' was not declared in this scope

        doSomethingEveryHour();

                             ^

Time_-_DoingSomethingNow:23:4: error: a function-definition is not allowed here before '{' token

    {

    ^

Time_-_DoingSomethingNow:27:1: error: expected '}' at end of input

 }

 ^

exit status 1
'rtc' was not declared in this scope

This report would have more information with
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#2

Which library are you using for the RTC? There are several options. Most require you to create the rtc object. Look at some example code from the library you're using and see if there isn't a line above the setup function to crate that object.

#3

It seems you have not instantiated an rtc.

Take a look at the site where you downloaded the library for examples, or see this tutorial: Interfacing DS1307 RTC Module with Arduino & Make a Reminder - Arduino Project Hub

#4

You seem to be mixing libraries. Code written for one library will not, necessarily, run with a different library. If you have installed the DS1307RTC by PaulStoffregen try the ReadTest example that comes with the library.

#5