vizio sound board

Code reuse is divided into static and dynamic. Static reuse is when you use certain features, include the corresponding header file. Dynamic reuse is a Linux driver that can use resources from another Linux driver. When compiling multiple source code files in the C or C + + language, if A.C uses the functions in the B.C file, you need to use extern to pre-define the B.C in the a.c file, and extern is to tell the compiler the function name, the number of arguments, the parameter type, and the ret

open and close. 13. Open and close PWMvia I/o command. 14. The close function of the PWM device fileStatic int s3c64xx_pwm_close (struct inode *inode,struct file *file)15. Releasing the semaphoreUp (lock);16. Open PWMPwm_start ();17. Stop PWMPwm_stop ();18. Initialize the semaphoreInit_motex (lock);19. Registration of equipment files/dev/pwm_den20. Removal of device filesMisc_deregister (MISC);21. I/o command, open PWM#define PWM_IOCTL_START 122. I/o command; stop PWM#define PWM_IOCTL_STOP 023.

The buzzer is also called PWM pulse width modulation, the basic principle is to control the buzzer by the pulse to open and stop. A buzzer is a hardware device on a development Board that can control the sound emitted by a buzzer by writing a specific value to the register. This section describes the principle of buzzer implementation and implements a complete buzzer driver that can be turned on and off. PW

The buzzer is a hardware device on the S3C6410 Development Board that can control the buzzer by writing a specific value to the register.In the previous chapters, two complete Linux drivers were written: Word_count Drive and LED driver, two have one thing in common is a source code file.Code reuse can be divided into two types: static and dynamic. An important code consumer is about to be compiled together, resulting in an executable file or library.T

Last year, the sound insulation panels on both sides of the Shanghai elevated road were not transparent; This year, the vehicle was on the elevated road in Shanghai, and the sound insulation panels on both sides added a middle transparent part. Let alone how much it will increase, but from the perspective of human nature, it is very desirable. Driving drivers can increase their horizons and reduce the p

8th: Make the Development Board sound: BuzzerOne, Linux-driven code reuseThere are many ways to reuse Linux-driven code. The standard C program can be used in the way. Put the code you want to reuse in a different file (declared in the header file). If you want to use certain features, include the appropriate header files (this is called static reuse). You can also use another way of dynamic reuse, where a

Through the study of this chapter I learned the following knowledge:First, the knowledge of buzzer: Buzzer is also known as PWM (pulse width modulation), the basic principle is to control the buzzer by pulse to open and close, the output pin of the timer and the transistor of the buzzer connected, this circuit transistor is PNP, when the pin is high, the transistor is in saturation, circuit conduction, Current flow through the buzzer, at this time the buzzer audible, conversely, when the pin is

The PWM,PWM driver can be opened and stopped by having an I/O command consisting of 3 files: pwm.c, Pwm_fun.h, pwm_fun.c. Where PWM.C is the driver main program. Pwm_fun.h refers to the corresponding header file and defines some macros. The Pwm_fun.c file contains two functions (Pwm_start and Pwm_stop) that open and stop the PWM. After running, from the contents of the makefile file, the compiler first compiles the PWM.C and pwm_fun.c files into PWM.O and PWM_FUN.O, then links the two *.o files

s3c6410 is a low power, cost-effective RISC processor from Samsung, which is based on the ARM11 core and can be used in mobile phones and general processing applications. s3c6410 2.5g and 3g 2d acceleration, display processing and scaling, and also integrates a mfc mpeg4/h.263/h.264 codec and vci decode to provide real-time video conferencing and NRSC and pal format tv output. Linux installation configuration and test minicom steps:First step: Detect whether the current

case, restarting the machine can To solve it. But it's too much trouble to restart the machine every time. Therefore, removing the Linux driver by directly modifying the Linux driver's corresponding memory address when encountering the inability to uninstall Linux drivers avoids the hassle of restarting the machine. Through the study of this chapter, I can master the common code reuse mode of Linux drive. Also learned how to forcibly uninstall Linux drivers. Through this method. Can save us fro

reference counter. The Unload function is blocked, and the behavior is that a rmmod command will stop there and never return to the operating prompt of the system, and the workaround is to replace the original unload function with an empty unload function. In the third section, the driving principle of buzzer is to control the opening and stopping of buzzer by pulse, which is called PWM.This chapter is a buzzer driver, the buzzer driver is more classic. In the learning process, you should caref

The buzzer is a hardware device on the s3c6410 Development Board. You can control the buzzer by writing a specific value to the register. This chapter will introduce the implementation of the buzzer to the original plow and achieve a complete buzzer drive (can turn the buzzer on and off). PWM time-driven implementation is different from the LED driver, the PWM driver will be composed of several files. This is also the standard implementation of most L

principle: Buzzer is also called PWM (pulse width modulation), the basic principle is to control the buzzer by pulse to open and close.13. Open and close pwm via I/o command.14. The close function of the PWM device fileStatic int s3c64xx_pwm_close (struct inode *inode,struct file *file)15. Releasing the semaphoreUp (lock);16. Open PWMPwm_start ();17. Stop PWMPwm_stop ();18. Initialize the semaphoreInit_motex (lock);19. Registration of equipment files/dev/pwm_den20. Removal of device filesMisc_d