I'm confused about how and when to use the reset button on the Arduino. Do I simply press the button while it is on? Is it simply restarting the board or clearing the uploaded code as well? Currently when I press the button while my Uno is powered it does absolutely nothing.

I have been using this board for many weeks with no problem and just now I have been getting this error:

avrdude: stk500_getsync()

And I cannot upload code. I tried using the reset button but I see nothing happening on the board, no blink, no flicker, nothing indicating something was reset.

1 Answer 1


The reset button does pretty much the same as unplugging the board and plugging it back in. It restarts your program from the beginning.

The same thing happens when you program the board - the USB interface presses the reset button for you. That then enters the bootloader for a second or two so it can try and program it.

When you reset the board the LED on pin 13 should flash a couple of times while it's in the bootloader before it runs whatever program you have programmed in. If that LED doesn't flash when you press the reset button then there is a serious fault with your board which will take further diagnostic.

  • If you have anything else plugged into the Arduino then unplug it.
  • Try powering the Arduino from different power supplies.
  • If you have another Arduino or an AVR programmer try re-flashing the bootloader.
  • Thank you. You've confirmed my suspicions. I've been trying to re-flash the bootloader with another Arduino but I keep getting errors for that too. Maybe it's because I didn't unplug everything or maybe because I have bad connections to the ATTINY pins. What sucks is that this Aruduino is part of a robot and I have all pins being used and hot glued into place. I was hoping for a better answer than unplugging everything. :| Jun 24, 2015 at 19:14

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