Is App Nap Freezing Your Interactive Projector?

app nap freezing

App Nap freezing interactive projector pens is an issue we were recently alerted to when we spoke with a customer who had several interactive projectors with the same problem – the pen would freeze and stop working. Users could still use the mouse and the Mimio software, but they were not able to use the frozen pen with the interactive projector. If this is a problem that you’re having, try this fix.

What is App Nap?

App Nap is the result of Apple trying to do a good thing for you and was first introduced with Mac OS X 10.9 Mavericks. When an app is completely hidden behind other windows and isn’t currently doing something for you, App Nap conserves battery life by putting the app into a paused state to save power and free up resources. As soon as you start to use it again, the app shifts back to full speed.

This is a great idea but doesn’t always work as intended with certain apps that you need to keep running in the background 100% of the time.

Stop App Nap Freezing Your Projector Pen

In some environments, like our customers experienced with their W307USTi Optoma interactive projector, the driver for the interactive projector runs like an app. These users found that App Nap was turning off the driver, thus freezing the pen and rendering it useless. Therefore, the simple fix is to turn off App Nap for that particular app or on the desktop entirely.

To turn off AppNap for an individual app:appwindow

  1. Go to the Finder and locate the application (In the case of the Optoma projector mentioned above, the “napping app” was LightPen3).
  2. Right click (or go to File in the top menu) and choose Get Info. A window like the sample to the right will open.
  3. Make sure that the checkmark is marked next to Prevent App Nap.
  4. Restart your computer.

To disable App Nap entirely:

If you’d rather disable App Nap entirely (which means less power saving and more resource using!), follow the directions in this article to disable or re-enable App Nap using Terminal.