I am working on a ballistics board for The AGROVATOR pumpkin cannon.agrovator.com
We have the tilt of the barrel controlled with an air motor. The XY axis is on a bearing from a tank turret. Even though it weighs a few thousand pounds, it is easy to move around.
I am working on a chronograph, and I have designed a potentiometer with a weight for the angle of the barrel measurement.
The barrel is 9 inches in diameter, so for the chronograph I am using LEDs and phototransistors.
The leds didn't werent bright enough at 12 inches apart.
In order to get the leds to be brightest without burning up I I drove the leds with PWM (instead of a resistor) and got the PWM port to read @ 4 volts with my meter. which is double of what the LED can handle.To keep it from burning up I turned it on and off at 6 milisec intervals.
Its not perfect but its an ok start.
With velocity and angle I should be able to get a good guess at distance.
Does anyone have any experience with pressure sensors that can handle abuse?
Is anyone else working on ballistics?