AVR and custom PCB, reset question

Looked at other projects, I have seen some with 5v directly connected to reset pin and sometimes there's also a capacitor (small one like 1uF) to ground. Other has a resistor inline with 5v to reset but no reset button, ICSP header, or anything to connect pin to ground.

My little PCB will not have a reset button so what is a proper way to handle reset pin? The chip will be socketed so if it needs code fix I can take it out. The PCB will not have reset button or ICSP header to keep it small. Straight to 5v and cap to ground? or skip cap?

This is a good reference for a minimal AVR circuit: http://www.gammon.com.au/breadboard As you can see, he has connected reset to 5 V via a 10 KOhm pull-up resistor. It's possible to do without but this will make your board more immune to spurious resets due to electrical noise.

If you look farther down the page where the FTDI cables is connected you can see that the cable's RTS pin is connected to the AVR's reset pin via a 0.1 uF capacitor. The purpose of this capacitor is to auto-reset the AVR to activate the bootloader when you upload a sketch over serial. Without that connection you will need to manually reset the board at just the right time during the upload. If you're not doing serial uploads then there is no need for any capacitor on the reset line.

Ok so cap isn't needed if there's no serial connection but why a pullup resistor? There isn't anything on my board that will pull reset to ground so unless there's a chance the chip can pull down internally, there seems to be no reason?

wilykat:
but why a pullup resistor?

pert:
spurious resets due to electrical noise.

The chip has an internal ~50 kOhm pull-up resistor but in a electrically noisy environment that might not be strong enough to prevent the pin from going low. As I said, it’s not absolutely necessary but it’s considered a good practice. Having your microcontroller mysteriously reset is no fun.

ah better waste a $0.02 now than to deal with randomly resetting chip later.

edit: lost a word. meant to say "waste a $0.02 resistor"

The other two choices are to disable RESET or tie RESET to VCC.