Programming VIP

Control LED light equipment Driver Essence: create corresponding device node files for hardware devices When creating equipment files, specify the use of equipment files. application program Control the hardware according to the device file usage specified by the driver Control hardware equipment steps 1. Find the device node file corres ...

LCD with 8080 timing There are four control lines of 8080: RD write enable, WR read enable, DC data / command and CS chip selection 8080 bus has many interfaces: 8 / 9 / 16 / 18 bit interface 8080 general timing Read timing LCD_CS = 0; //Film selection LCD_DC = 1; //Read data LCD_WR = 1; //No writing LCD_RD = 0; //Start readin ...

preface I got the Nezha development board in advance. When I was excited, I began to study how to run my bare metal program, which is called operating system Unlike mcu, sbc level cpu is much more complex to run, but fortunately, in the field of system level, the division of labor of different software is clear. Our bare metal program, as the ...

4.4 touch screen application interface 4.4.1 introduction to input subsystem There can be more than one input device connected to the operating system, perhaps a standard PS/2 keyboard, perhaps a USB mouse, or a touch screen, or even a game console joystick. When dealing with these complex and different input devices, Linux still uses the mid ...

File open, file write, file read, file close, file cursor lseek, file create The general process of a file is to open or create a document - edit the document - save the document - close the document. The api (Application Programming Interface) provided by liunx file operation includes open, write, read, close, lseek, create, etc. File op ...

14. Device tree 1. What is a device tree? Device tree is a data structure that describes hardware resources. It transmits hardware resources to the kernel through bootloader, making the description of kernel and hardware resources relatively independent. 2. Origin of device tree To understand why there is a device tree and how it comes from ...

First of all, the server needs to be configured with nfs and tftp, which have a lot of information on the Internet and are omitted here. In this example, my server address is 192.168.88.18, and the nfs and file system directory is: / home/ubuntu/disk-2/nfs_rootfs, tftp directory is: / home/ubuntu/disk-2/tftpboot. Kernel zImage and device tree f ...

1. Introduction to asynchronous notification 1) Interrupt is an asynchronous mechanism provided by the processor. After configuring the interrupt, the processor can handle other things. When the interrupt occurs, it will trigger the interrupt service function set in advance and do specific processing in the interrupt service function. 2) ...

summary A2SA is the abbreviation of advanced AliOS Things sound architecture. It is the service framework of AliOS Things audio system, including audio driver layer, audio service interface layer and audio plug-in management. Some design concepts draw lessons from the design ideas of Linux ALSA, such as supporting VFS device driver mount acc ...

summary HTTP(HyperText Transfer Protocol) is an application layer protocol used to transfer hypertext. The network protocol stack of AliOS Things includes HTTP components and provides HTTP client standard capabilities. Developers can quickly realize data interaction with the server through HTTP GET, POST and other methods on the device side ...