Hi,
All posts about an RTC referes to adding a DS1307 chip. But as I understand it, the SAM3X8E has an internal RTC. I'm haven't done any low level coding to access such a feature as of yet. Is this going to difficult to do over buying an external RTC chip?
Maybe I am missing something obvious, if so feel free to correct me.
Any hints and tips would be much appreciated.
Thanks, Dei
Yes, the chip itself has RTC built-in. You can download a library to work with it here:
However, the people who developed the Due, in all their wisdom, decided it would be best to tie the RTC power pin to the rest of the Arduino Due power. This means that you cannot power the RTC independently of the rest of the system and thus the RTC goes dead as soon as power is removed. This tends to be a real downer. You need a custom board to get around this.
Hey, ok cool. So it works in the sense that it can reliably keep time, this is just to make counts on a traffic light led. So i want it to be accurate as long as it's powered.
I don't want anything interfereing with a basic timer (if that makes sense).
Thanks
millis() is perfectly accurate for a traffic light. It also doesn't require any external libraries.
If you use millis() then your code can run on any Arduino straight out of the box.