Arduino Mega 2560 ICSP and Automatic Software Reset

Projects Programming
1

Hi,

I read this about the Arduino Mega 2560 Auto-Reset feature.

The Mega2560 contains a trace that can be cut to disable the auto-reset. The pads on either side of the trace can be soldered together to re-enable it. It's labeled "RESET-EN". You may also be able to disable the auto-reset by connecting a 110 ohm resistor from 5V to the reset line; see this forum thread for details.

If I cut the trace will I be able to program the Arduino through the ICSP without having to press the reset button or does cutting the trace also force you to use the reset button when programming through ICSP just like it does for the USB. My feeling is it doesn't since the ICSP has a reset line as well, but I am unfamiliar with the ATMEGA16U2.

Thank You
Patrick

2

It won't affect ICSP. Reset has to be held low during ICSP programming, and that signal is brought out through the 6-pin ICSP header.

3

Yep, that Reset-En is to prevent the USB/Serial from creating a reset.