Shooting targets at varying unknown distances can be a challenge even for experienced shooters. Judging bullet drop can be a difficult task, and manual adjustments in the field are cumbersome. This process can be simplified by using existing technology and formulas. The auto-adjusting scope will make the proper adjustments so the shooter doesn’t have to, thus saving time and improving accuracy. General Background: Currently rangefinders can be used to approximate distances to targets and shooters can manually readjust their sights or hold their sights over the target. However, formulating an exact bullet drop in the field is an awkward process, which is why most people choose to guess bullet drop, but this method is unreliable. A device mounted to a gun that would compensate for different shooting distances would provide the user with a considerable shooting advantage. Technical Problems: Component interfacing: rangefinder sensor, microcontroller, LCD, shooting scope, keypad, and servo Calculating bullet drop: using distance to target, predefined formula, and pre-entered information Adjusting target scope: according to drop calculations Design Objectives: Design a simple user interface that will allow entry of bullet information Design flexible formulas that can be used for multiple calibers Make the scope adjustment system automatic Target shooting at a variety of distances Testing will be done with.22 caliber rifles Acceptable results will be a pattern of five inches in diameter Testing will be done on the bullet drop formula The microprocessor will be tested by comparing hand calculations with the correctness of programming The laser rangefinder will be tested at a number of distances and also tested to see the types of objects it picks up The end result of the product will be a portable device, to be mounted to a gun that will automatically adjust the sights of a scope to compensate for bullet drop. Operating Environment: Temperature: –20° F and 110° F Humidity: 0% – 90% Shock: Bullet discharge Assumptions: Bullet drop can be accurately calculated Assume bullets from the same lot hold close tolerances Intended users: Hunters Target shooters Military Limitations: Effective shooting distance: 400 – 600 yards Servo and microcontroller must fit on riflescope Personnel Effort Estimate Jenny Custer186 hours Danielle Frey189 hours Eric Halbur200 hours Brad Retterath192 hours Total estimated effort767 hours Functional Requirements: Allow data input Allow pointing of the sensor at a target Calculate bullet drop for a given distance Auto Adjust scope’s vertical adjustment Design Constraints: Time Budget Space: Must be small enough to attach to gun Caliber: Prototype,.22 caliber rifles only Measurable Milestones: Finding a suitable formula to calculate bullet drop Finding a servo with enough torque to turn the vertical adjustment on a standard riflescope Acquiring a laser rangefinder sensor with serial interface Designing a user interface that will allow for user input Designing mounting hardware to mount the servo to the scope Total: $1,400 $40 $110 $50 $1,000 $40 $60 $100 MicrocontrollerMiscellaneousServo/Motor SensorMounting HardwareLCD & Keypad Scope Estimated bullet drop on.223 caliber rifle. Scope sites always on a target on X-axis at zero. ClientFaculty AdvisorTechnical AdvisorTeam Members Senior Design Project Dec02-08 Project will be broken down for simplicity Bullet Drop Table Eric Halbur Dr. Randall GeigerLTC Marvin Meek Jenny CusterElectrical Engineering FreyComputer Engineering 135 Oriole St351 Durham132 ArmoryEric HalburComputer Engineering Ames, IA 50010Ames, IA Ames, IA 50011Brad RetterathElectrical Engineering