Iam using Ardunino uno with a wifly shild and other stuff.
This setup will be outdoors and I want to make 100% sure it stay connected and operate as good as it can.
My plan is to restart the Arduino every 24hr to make sure it reconnects if something goes wrong.
How can I restart Arduino with wifly shild every 24 hour, making arduino restart and wifly reconnect ?
You could add an external device to reset the device, or you could run a simple background (look at "blink-without-delay" for an example) "task" to perform a "soft reset" like this:
Note that that is not a true hardware reset, so the processor isn't put into exactly the same state as if it had been reset by a pulse on the reset pin.