Programming Arduino for time of day scheduling

Looking for a program that can turn on/off etherent relays from Andriod or web based interface
must be able to use a calendar scheduler, i have seen many applications that allow real time ON/OFF control of relays, but I have not yet seen a ON/OFF control that can be set for weekly events
WE are a company that builds/designs remote relay activation in schools to handle their class change notification, however most schools have preset weekly schedules so we need to program the Arduino to execute a weekly schedule.

Many Thanks

The Arduino does not have a built in real-time-clock but you could buy a shield giving the calendar functionality you require.

must be able to use a calendar scheduler

Can you explain in more detail what you mean by this?

Agree with Radman's advise. You should at least buy a Real Time Clock.
I like - Overview | Adafruit Data Logger Shield | Adafruit Learning System - because it allows you to log all actions done.
And 2nd, it allows you to put the schedule on disk in a txt file so it is available after a unexpected reboot (those happen).

You might find the TimeAlarms library useful

do any people in this form undertake paid programming?


See the Gigs and Collaborations forum.


You don't need a Real Time Clock if you have ethernet, and it's connected to the web, you can get the time from the web. Take a look at the "TimeNTP" example sketch that comes in the Time library.

Once you have the current time, you can just make an if statement. Something like this:

time_t t = now()
if (weekday(t) == 0 && hour(t) == 10 && minute(t) == 0 && second(t) == 0) {
   do something;

This would trigger on Sunday at 10:00AM

Mention has been made of using a library and also getting the time over the internet.

The OP seems to want something for use in schools. I had discounted using the software library because I thought there might be a drift over the course of a year (any idea how much this would be?) and I thought schools might not like having to adjust the clock. Connecting to the internet also, to me, seems to add a layer of complication that schools might not want to deal with e.g. firewall inadvertently cutting connection, extra wiring or a wirless connection etc.

Yet another option might be picking up a radio time broadcast, but for that you need reception of a good radio signal.

All in all a real-time-clock shield seemed, to me, to be a clean self-contained solution.

Strange, I just spent the past 30 hours programming just such a system which has a web based GUI to program the schedules and choices of days they are to be triggered....