The main thing most security people look for are weapons and explosives. A laptop is going to get a more through examination then a Pi, because the battery is

The main thing most security people look for are weapons and explosives. A laptop is going to get a more through examination then a Pi, because the battery is a big hunk of something, and if it were a bomb, that would be an issue. That's why they often ask about you to turn on your laptop. I'd be more worried about it being pilfered if you check it then it being a security issue if you take it in the cabin.