I'm trying to create an ammo counter for an airsoft gun. I'm going to control it with an attiny series MCU and i want to detect the projectiles exiting the barrel using a light based sensor. Now that's the question:
Which method of detection is the best for such application? A photodiode, a phototransistor or other, perhaps laser based sensors?
The projectile is 6mm in diameter and at 115 m/s after exiting the barrel which means that the sensor will have around 70μs to detect it.