I finished up a simple project that I want to keep plugged into the wall at 5v on the Arduino nano. All it has connected to it is a relay board. Can I keep this plugged in for years or will it fail? If it fails, what are some preventions to make it last longer? Otherwise how do I finalize my product if I wanted to give it to someone? Thank you
As long as all solderings do their jobb. Keep the boards within their specified environmental specifications helps.
Can Arduinos run forever?
No
Can I keep this plugged in for years or will it fail?
It will possibly fail as components can deteriorate, power supply problems can occur.
what are some preventions to make it last longer
Design for cool running.
Add SWC (surge withstand capability) to inputs/outputs.
how do I finalize my product if I wanted to give it to someone
Put it into a box.
But really, we need to see what you have done.
Years? Yes. Forever? No.
The environment makes a difference: vibration or salt air are killers. Indoors in a regular house not near the ocean, I expect you will get 5-10 years with no special effort.
Are there any wires or connectors that move?
Whilst we may assume Arduinos will not run forever, we can have no way of knowing that for sure as you would have to wait forever to find out ..............
I had a Nano continually running a sketch for three years now without issue , if that helps .
srnet:
Whilst we may assume Arduinos will not run forever, we can have no way of knowing that for sure as you would have to wait forever to find out ..............
It'd takes till arduino fails, not forever, about 10-15 years.
If you want it to run 'forever' you'd have to replace your regular Arduino with one made with through-hole parts, or at least larger scale than what is used on a regular Arduino.
(Google for 'tin whiskers'. It may be tempting to also use solder containing lead... )
Avoid electrolytic capacitors...
Gold-plated contacts whenever soldering a wire directly isn't a good idea.
But most likely, the relay board is the part that will fail first.
Normal relays have a lifespan(usually listed as how many times they can be triggered before breakage is likely), and if they switch a lot of power, or high voltage, you can get sparking resulting in deformation or even welding the contacts together.
(Anyone who has ever fiddled with old cars that had 'points' in the distributor will be all to aware of contact deformations... )
MorganS:
Years? Yes. Forever? No.
Isn't that a bit too dogmatic? Nobody has yet proved that one can't run forever 
...R
Robin2:
Isn't that a bit too dogmatic? Nobody has yet proved that one can't run forever...R
At some point the Universe will come to an end. Some time before that the total energy level of the Universe will be too low to support a working Arduino. A bit like the battery running down but on a somewhat larger scale.
Steve
Robin2:
Isn't that a bit too dogmatic? Nobody has yet proved that one can't run forever...R
See you in 2319.
we submitted some pnuematic transmitters for testing for the nuclear industry.
two aluminum blocks, mylar film. screws
they only would give us a life of 420 years.
so, I am going to say that as neutrinos pass through the electronics, some atoms can be altered.
over some length of time, there will be degradation.
as for electronics, since Sun is going into a minimum and we may see the rivers freezing over again like the last time the sun went into such a minimum, and if it is the end of the current inter glacial era , there will not be anyone around for some time to give you the answer.
and, since we are told that CO2 is causing a runaway greenhouse effect and we will never seen snow or ice again, and people will not be able to survive..... again, no one will be around to give you an answer.
Robin2:
Isn't that a bit too dogmatic? Nobody has yet proved that one can't run forever
Actually, the retention of the Flash ROM will likely be a limiting factor.
Keep it cool.
Paul__B:
Actually, the retention of the Flash ROM will likely be a limiting factor.
As the Atmega 328 is capable of bootloading its program memory I wonder would it be possible to program one to "refresh" its flash every few years? It would probably require 2 copies of the program in program memory.
Just a stray thought. I have no intention of further research or experiment. Life's too short.
...R