The portable feature of a green laser pointer
Option One: The 51 single Option Two: Option Three with the MSP430 microcontroller: microcontroller with ARM32 characteristics of single-chip microcontroller solution in contrast to Table 3 Comparison of characteristics of the program the microcontroller using the advantages of using single-chip AD converter without using the internal weaknesses. The battery electric quantity indication is used for indicating the service condition of 50mW blue violet laser pointer.so do note the need to control development board using the AD converter chips 8591, did not pass the test program, no debugging MCS-out 51 commonly used microcontroller, easy to use, free to operate the chip comes with a 8591 development board involved in the I2C, write the program error-prone chips do not commonly used, is not readily available, and not used, can substitute with other microcontrollers ultra-low power consumption, and many of their predecessors with the MSP430 MCU's second point light sources do not use this chip to track internal AD and 6 Operation ARM32 own internal AD converter, no external action more difficult, the program has a fixed zero-based AD function plus write-chip basis to borrow from is not easy to achieve, can facilitate the achievement function from the beginning we chose 51 microcontroller, its functions can achieve the requirements of the title, but written more than 200 lines of code, no matter how debugging are looking for can not be achieved light, we analyze most likely due to their sensitivity is not high photosensitive resistor,The battery electric quantity indication helps to judge if it needs to change the battery of 200mW green Laser Pointer. the voltage did not change significantly when the bright light (light 0.4V, light 1.5V) and by the PCF8591 chip AD conversion of the error is greater, leading to can not track a point source,. In order to overcome the 51 single-chip AD converter does not own internal problems, we decided to use ARM32 microcontroller. 3 looking for light motor program a summary of the options: DC motor driven by the photosensitive system test circuit, the results show that the use of DC motor drive system of photosensitive light detection scheme has many advantages: less use of resources microcontroller port, without multi-channel data acquisition AD mouth , only two AD extraction signal; motor control method is simple, no set rotation direction of the program, the hardware automatically light precise positioning, precise control and trace amount of incident light will cause the motor to rotate, adjust to the center position. However, the program also has many shortcomings, DC less susceptible to single-chip control, the program can not effectively control the rotation angle, for a fixed angle of rotation is more difficult, not photosensitive system is software that accurate reduction. The 100mW green laser pointer has a timer.Option Two: stepping motor driven photosensitive system, precise control of rotation of the stepper motor is the electrical pulses into angular displacement or linear displacement of the open-loop control components. In the case of non-overload, the motor speed, stop position depends only on the pulse frequency and pulse number, regardless of load changes, that is, to add a pulse motor, the motor is turned one step angle. The existence of this linear relationship, coupled with periodic error of the stepper motor only without the accumulated error and so on. Makes the speed, position and other control areas to control the stepper motor becomes very simple.The timer of green laser pointer would vibrate when the set time is up. After the signal processing circuit into the microcontroller, the microcontroller logic through accurate timing control of stepper motor rotation angle, rotation direction makes the photosensitive system accurately controlled, more convenient software reset, the motor feedback control point of deviation, the formation of closed-loop control, through experimental research.
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