so I’m working with arduino and i need to make a lcd display that’s shows the clock after the user have set it and keeps it updated ... on my lcd display i Goth 5 buttes but i have no idea on how to keep track off time in code i been looking around and it's seems like people are using some external hardware to keep track off time external hardware is not an option for... so i need some code that can keep track off time after the user have set the time ... anyone have some idea on how i can do this???
Have a look at the Time library but the clock will not be very accurate without a Real Time Clock (RTC) which is the external hardware that I suspect you are referring to. Other methods, such as connecting to a time server on the Internet would be another, more complicated, option.
Which Arduino are you using? If it's a Leonardo, it should be quite acurate anyway. If it's a Uno, it will be less accurate - because the Uno uses a ceramic resonator, not a crystal - and more sensitive to temperature.
With a little work, you could change the Time library to make a fixed correction for your Arduino's clock frequency being slightly off.
external hardware is not an option for... so i need some code that can keep track off time after the user have set the time ... anyone have some idea on how i can do this???