i would to know how i can command the reset pin in arduino without push buuton

i would to know how i can command the reset pin in arduino without push buuton

There are several different ways. Assuming that you want to software-reset the Arduino?

You can setup the watchdog timer. The WDT requires running code to periodically reset the WD timer. The idea is that if a running program crashes, it will stop resetting the watchdog and the timer will time out, resetting the Arduino (and hopefully fixing the reason it crashed). But this can also be used specifically to generate a reset - just set it up for a short timeout period, then don't update it and it will reset the CPU.

Another way is to connect an unused digital output to the reset pin. Just "digitalWrite" the pin low and it will reset the Arduino. Since the AVR will reset with all pins as inputs, you won't get stuck in an endless reset.

Another way is to simply "jmp 0" with assembler (like this):

   __asm__ __volatile__ (
        " clr r30\n"
        " clr r31\n"
        " ijmp\n"

There may even be other ways, but I can't think of them at the moment.

The Watchdog timer method is the preferred method. Of course, the VERY BEGINNING of your code needs to DISABLE the watchdog timer, so that at reset it doesn't time out again (I believe the watchdog timer stays active through reset).

Your code needs to look something like this (pseudo-code):

    setup {
        disable the watchdog FIRST
        do the rest of your setup

    loop {
        run your usual...
        code here and...
        set the watchdog ONLY when you want to reboot!

Hope this helps.


Talk to this guy - he has a very similar problem, and very identical email and IP addresses.