Saying non credible af here, but in theory one could add a upwards facing shotgun shells on top of the helmet, triggered by a Camera/proximity sensor if it detects a drone/falling grande. Maybe add a gyroscope to check if the helmet is actually facing upwards before triggering. All in all unit cost could be below 250$
- 6x 12 gauge shells with bird shot
- Raspberry pi type controller
- USB cam
- Laser distance sensor
- gyroscope
- servo trigger
Bird shot doesn’t hurt when it falls on you, unless it gets in your eye. The recoil from the shot might be enough to cause serious neck damage.