Electronic – Do I need a Reset Switch

atmegamicrocontrollerreset

I'm trying to make a ATmega328 run on a breadboard.

I am stuck on deciding if I need a reset switch.

Do I need one? Can I just unplug and plug in the battery instead? If I do need one, how would I go about doing this?

Best Answer

The ATmega can work without a reset button. Powering down the controller will reset it, as the O.P. expected. In-circuit programmer will also reset the controller every time new firmware is loaded.

If it becomes apparent that a reset button would be a nice thing to have, it can be wired like this:

enter image description here
Source: Atmel application note AVR042 (AVR Hardware Design Considerations) p.6
There is also a simplified approach, although be sure to read the comments made by @vaxquis below.

Since the circuit is built on a breadboard, one can always take a wire and touch between RESET# and ground. That will momentarily bring the RESET# to ground, which will reset the controller.

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