This is my first version of Ballistic Chronograph. They are used to measure the speed of a bullet. There are various ways to do this. I used optical system to detect the pass of the bullet and it’s speed.
Device has two screens and bullet passes through these screens. Each screen consists of 5 IR LED – photodiode pairs. So passing of a bullet detected with optical sensors. The weak signal, which is produced during the bullet pass, is amplified and goes to the ATMEGA8 microcontroller for triggering an interrupt. Screen 1 output triggers an interrupt and starts the timer. Same way , screen 2 stops the timer. With some calculations on microcontroller bullet speed is shown on LCD.