Endurance

I am going to run code in arduino board continuously for 3 months. Do you think it can stand it without affecting intended functionality?

Without seeing the code? No comment.

I have an Atmega 328 on stripboard running 24/7 for nearly a year now.

...R

Yes.

As far a the micro goes you can run for as many years as you like, I know of 100,000 of micros which have been running that long.

Mark

jismagic: I am going to run code in arduino board continuously for 3 months. Do you think it can stand it without affecting intended functionality?

Atmega_datasheet: – Data retention: 20 years at 85°C/100 years at 25°C(1)

Reliability Qualification results show that the projected data retention failure rate is much less than 1 PPM over 20 years at 85°C or 100 years at 25°C.

As long as it's not in space... If it is, make sure to wrap it around with a lot of aluminium foil. My biggest concern would be the on-board regulator.

I've had an AVR chip run continuously for about 4 years; it's not a problem. Humidity, temperature, vibrations-this will all affect the reliability of the device. Make sure your input voltage isn't too high; 9 volts is about it, excess energy gets converted into heat when it's not powered from USB. Even if you put it high, it will still be okay. 3 months is not an issue.

I built a car alarm with a different-older microcontroller and it's been running continuously in my 1994 van for almost 20 years with no problems! It runs a 24/7 and and is enabled/disabled depending on the state of an input pin, so it never gets turned-off or reset. It only gets turned-off & rebooted when the battery in the van has to be replaced every 3 or 4 years.

Now... I wouldn't send it into space or use it for medical life support, because it's just not built that well (it's built on a "breadboard") and there is no redundancy, back-up, fault detection, or fault-tolerance. But, it's been doggone reliable.

jismagic:
I am going to run code in arduino board continuously for 3 months. Do you think it can stand it without affecting intended functionality?

Unless you are foolishly using EEPROM for continueous writes that would exceed the recommended maximum in the 90 day period.

Ray