Control a sentry gun using a Recon Snow2 HUD installed in a set of UVEX G.GL9 ski goggles.
Since the mechanics of the sentry gun are just two servo motors, you could easily modify this Instructable to control any device using "up/down", "left/right" head movements.
This is an "add on" to my previously published Instructable "WiFi / Internet / Android Controlled Nerf Vulcan Sentry Gun". Please visit that page for full details on the platform being used here.
In addition to all the parts required for the sentry gun, you will require ...
1) UVEX G.GL9 Ski Goggles, or equivalent. See the Recon website for compatible goggles.
2) Recon Snow2 HUD
For more information, visit the Recon website.