# Powering Off Main Processor Without Software shutdown

I am building a robot that uses an Intel NUC (running ArchLinux) as its main processing unit to run some machine learning and ROS programs scripts. One of the requirements for the robot is that it must fully turn off and on by a single main power switch. By doing so, it cuts power to the entire robot, including the NUC. I am worried that doing so will damage the NUC. Is there any safe way to shut down a computer without having to turn it off via software.

**One more requirement for the robot is that its electronics are sealed in in an airtight box, therefore the NUC cannot be accessed to turn off via the main power button.

Most PCs can survive power loss. Here is a video showing how to configure the NUC BIOS to restart on Power On after Power Fail.

I would be more concerned about your comment that it must be "sealed in an airtight box"! PCs generate a lot of heat and they need a way to get rid of it. If not, they will overheat.

There is a fan in most PCs. The fan is not always obvious (they often like to hide it); but, when it is there, it needs to be able to circulate air to keep the PC cool. Here is a video about that.

Note: Even if you have a fanless computer, it will still require some sort of air flow (possibly convection) to prevent it from overheating. For example, this fanless NUC has a max operating temp of 40C (104F). Even a hot day WITH air circulation it can overheat it. Without a source of fresh air, this it going to be much worse. Remember what happens in your car on a summer's day when you leave the windows rolled up.

• Thanks for you're answer. The electrical enclosure achieves thermal relief through a rear heat sink that is passively cooled. No worries about it getting too hot. Thanks for your concern though! – Theodore_Kim Feb 14 '18 at 13:39

The main two things I do for an a linux system for which I want to be able to kill power freely are:

1. Choose appropriate filesystems and configure them to recover cleanly on restart. The choice depends on your storage hardware, most journaling filesystems work fine for this. Mounting as much as you can read-only also helps.

2. Make sure that all processes needed for operation clean up their environments and automatically started cleanly. (Clean up temp files, rotate log files, etc)

Searching linux filesystem power loss will get you started with selection and configuration recommendations.

Note that providing too high a voltage to the NUC can damage it and an improperly designed robot electrical system might spike high in a poorly sequenced shutdown from one of the energy storage elements (usually kinetic from the moving mass of the robot or inductive from the motor or power supply coils).