its rotation angle can not be precisely controlled

Point source tracking system
Abstract The design of the TI's ultra-low power MCU MSP430 processor core, designed and produced a white LED to detect and track the location of the light point source tracking system. The receiving distance of the receiver of green laser pointer is influenced by the surrounding environment.Through the use of sensor (photo diode), the light intensity into a voltage signal and amplified, sent to AD conversion, and then calculated by the MSP430 microcontroller and analysis, using the results, control the stepper motor driven light pen operation, accurately track lighting the movement.Therefore, please use the green laser pointer far away from other electronic equipment.Option three: use the photodiode as a photosensitive device. photodiode with semiconductor diode is similar in structure, The die is a photosensitive characteristics of PN junction, with one-way conductivity, so need to work with reverse voltage, the detection of a wide range of its light curve and the volt-ampere characteristic curve as shown below: photodiode light photodiode volt-ampere characteristic curve curves take into account the light source to the sensor when the light side is weak, high sensitivity, the photodiode can be used with a wide detection range, as coarse. so option three. 3 1.2 light The following picture shows the light irradiation test program photosensitive device schematic: Photodiode group A (four) light laser pointer circular turntable photodiode group B (four) Option One: Option One: Please don’t sell the green laser pointer products to persons who are younger than 18.DC motor drive DC motor is the rotary laser pointer DC can be converted to mechanical energy of rotating equipment, motor stator to provide magnetic field, the DC power supply provides current to the rotor windings, commutator so that the magnetic field generated by the rotor current and torque remain constant direction of its speed performance, wide speed range, Speed can be adjusted to achieve uniform, but its difficult to change, will produce sparks, short life, and its rotation angle can not be precisely controlled.
Third, the overall system test and analysis of test steps shown in Figure 3.1 shows, the center line and stand between the light source angle θ is about 60, Light from the ground height of about 100cm, 3 cm from the light source, the light axis perpendicular to the plane set on a diameter of not less than 60cm dark cardboard. A light source placed in the ground tracking system, by using the photosensitive device detects the light intensity to determine the source position.Don’t use the detergent or other chemical solvent to clean the green laser pointer. Test in normal indoor lighting, tracking system A is not correct for the direct sunlight and strong light. 8 Step one: light laser pointer tracking system can point to the scene as soon as possible to set parameters of the point light source. Option Two: Select the servo motor, high precision control system, but not easy to achieve in low-speed control. And and the price is expensive. The green page-turning green laser pointer is more expensive than the red one.Option Three: Select the stepper motor. Characteristics of the stepper motor can be precisely controlled step motor selection and angle is a little out of step but more than in the frequency of 400HZ-step less. Taking into account the subject requires higher performance, so we choose the stepper motor, through good control algorithm to achieve high-precision positioning. Convenient control of high precision. 1.3 angle sensor option 1: The perspective of a Finnish SCA100T acceleration sensor response flat angle, high accuracy of the feedback it can reach 0.01 degrees, but it is the acceleration sensor in the swing acceleration in the process of changing its makes its point of view has changed inaccurate reading.That’s because the module applied by green page-turning green laser pointer is more expensive than that of red one. Option II: The angular displacement sensor, high accuracy, without acceleration effects. And easy to control. Taking into account the accuracy of the problem we have adopted a program two. Control of high precision and easy to control.