did you install the RTCLib? You should have: Documents > Arduino > libraries > RTCLib > RTC_DS1307.h
Thanks for the post. I used RGB Neopixels rather than RGBW LEDs. I believe RGB is more common than RGBW, so check your strip before adding the "W". But good heads up. Also the code currently has the LEDs on pin 3, which is working fine on mine, but it's fine to change it to 6 as long as you modify the code.
In the code on github? I see "#include <RTC_DS1307.h>" here: https://github.com/jdeboi/Classroom-Clock/blob/master/Code/classroomClock/classroomClock.ino
the Uno should work fine (mine is currently running on an Uno; I replaced the Nano). the rtc ds3231 should work too, but there may have to be minor tweaks in the code. Not sure.
Can you post the error message? I bet it has something to do with the library. Might be something related to the RTC library which I might have to fix. try changing:dayOfTheWeek() to dayOfWeek()? (or possibly vice versa)
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