It is similar to a pipe but created in different ways. Here mkfifo ( ) function creates the file in file system. mkfifo ( ) makes a file named pathname. Pathname is the location of FIFO file where it is created. Once you create the file, you can read or write it as defined in mode user permission what user wants to do with FIFO file.The system call mknod ( ) creates file system node as specified pathname with attribute described in mode and dev. Once you have created the file, you can read or write as defined in mode.which seeks user permission as to what user wants to do with FIFO file. dev define the types of file system node (i.e. file, device file, socket, named pipe). The file type must be one of S_IFREG, S_IFCHR, S_IFBLK, S_IFIFO, or S_IFSOCK to specify a regular file, character file, device block file, named pipe and socket respectively.
FIFO or named Pipe ( Part 16/24)
I already explained about pipe in tutorial Pipe in Linux. FIFO or unnamed pipe is same as pipe or named pipe expect for one thing. Pipe is a one way communication between process which is related to each other like parent and child processes. Related processes have same file descriptor, so they communicate easily through single pipe but unrelated processes have different file descriptors, so they cannot communicate through single pipe. You can communicate only through creating multiple pipes each for one communication. Communication between multiple processes is not sufficient and hence FIFO or named pipe overcomes this limitation.FIFO (First In First Out) is first out file which is like normal file but doesn’t save the content of file, it should pass data, write or read by first in and first out process. When one process is read or written using FIFO, another process waits to access FIFO. So FIFO can also be used for one-way communication between multiple and unrelated processes instead of single and related process.
Measure Temperature using LM35 Interfacing with Beaglebone black (Part 15/15)
This tutorial explains how to interface LM35 Temperature sensor with Beaglebone black to work with sensor interfacing. LM35 is an analog sensor which measures the temperature and linear output given in voltage form. I have interfaced temperature sensor LM35 with 12 bit ADC of BBB where output of LM35 is in analog form and output of ADC is in digital value and later is converted in Celsius and Fahrenheit by formula. LM35 is with 3 terminals- Vcc terminal is connected with 3.3 V supply, Ground is connected with ADC ground of BBB (pin number 34th of header P9) and Output terminal is connected to the input of AIN1 (pin number 40th of header P9). Now you can open the command terminal and take an access of Beaglebone black through SSH as explained in getting started with Beaglebone black.
Autorun Python Script on BeagleBone Black Boot (Part 14/15)
When you execute python script from SSH command prompt, you need to make BBB connection with PC because you are accessing the BBB through SSH connection. If you wish to run Python Script on BeagleBone Black Boot without connecting it with PC, an external power is needed to be supplied. You can run python script when you power up BBB without any command prompt or command by Crontab. Crontab is a task management tool which is built-in into Debian and then we can add the new Cron Job at which a Python script will run at boot. When script is running, both the LEDs are switched ON and OFF for one second.
WI-FI Configuration with Beaglebone Black (Part 11/15)
This tutorial explains how to connect Beaglebone with WI-FI adapter for internet connectivity. Before proceeding, we need some basic configuration as well as an internet connection. First connect the internet through Ethernet. Complete step-by-step guide to get WiFi running for your BeagleBone Black to manually configure the adapter to automatically connect with your network. Before you get started make sure that you are running the latest official Debian image on BeagleBone Black. Here, I have used EDMAX which works with almost any kind of WI FI adapter.
Web Cam interfacing with Beaglebone black (Part 10/15)
Web cam is needed for image capturing and video streaming applications. You can interface web cam with Beaglebone Black and capture the picture and video as well. In this tutorial I will interface Logitech web camera with BBB. I have explained step by step setup of web cam interfacing with BBB. Before connecting web cam, I will explain about VNC remote connection of Beaglebone Black. If you get SSH access of BBB, it will not display image or video due to insufficient GUI. So you need to take virtual remote access of BBB on desktop.
Sending Mail from Beaglebone Black (Part 9/15)
This tutorial explains how to send mail from Beaglebone black using SMTP protocol. SMTP stands for Simple Mail transfer protocol. The main objective of this tutorial is to obtain mail notification upon certain activity. BBB will send the mail with predefined message to registered email id when some activity takes place.In this tutorial, simple alert notification is sent to specific mail ID. Before running application, you need to establish internet connection with Beaglebone black. You can choose either Ethernet connection or WI-FI device.
Magnetometer interfacing with Beaglebone black (Part 8/15)
This tutorial explains how to work with magnetometer and Beaglebone black. Magnetometer senses the low magnetic field and works as a digital compass. It is used in tracking or navigation application. In this tutorial, HMC5883L magnetometer has been used and interfaced with Beaglebone black through I2C protocol. Program is written in python script with adafruit I2C library.HMC5883L is 3-axis low magnetic sensing and digital compass device. It is supported by I2C interface. It generates sensitive magnetic value during simple measurement. Value and degree of angle are displayed on SSH prompt every one second.
Sending Data from Beaglebone Black to Arduino Through UART (Part 7/15)
This tutorial represents communication between Beaglebone black and Arduino through UART. You don’t need any another peripheral for this tutorial. UART stands for universal asynchronous receiver and transmitter. It transmits and receives data asynchronously with another device which also supports UART protocol.Beaglebone transmits the message which is entered from command prompt and Arduino receives the data and displays it on Arduino serial terminal. Run the python script from SSH terminal and at the same time open Arduino serial in PC.
How to Make First Python Program with Beaglebone Black
Beaglebone black supports various high level languages such as a C, C++ and scripting languages like java, python. Programming of application is mostly written in C language for controller or processor. Python is an interpreted language and great library source available for BBB. At low level, programming in python is efficient and responds quicker than C language.This tutorial talks about making first python program with Beaglebone Black. So in case you are not aware of basic python programming then I suggest you to go through the same before proceeding.
DC Motor Interfacing with Beaglebone Black
This tutorial explains how to interface DC motor with Beaglebone black where DC motor acts as an actuator device. Due to insufficient current, it’s not possible to drive the motor directly from BBB and hence a motor driver IC is needed.Program is written in python script with Adafruit GPIO library.Install the latest python version in BBB as explained in tutorial How to make first python program with Beaglebone Black. Install the Adafruit python-GPIO library named adafruit_BBIO.
How To Create Process In Linux (Part 10/15)
The Process is an instance of a program code which executes within the operating system. The Process is nothing but carry out of the task. Refer the previous tutorial Process in Linux. This tutorial will explain how to create a process in Linux.Fork () system callThe process is created by fork () system call. Fork () creates a new process from the existing process. The existing process from which function called is known as parent process and newly created process is known as child process. Child process has its own process ID. Fork ( ) takes no argument and return process ID. If successfully fork ( ) system call run, it returns twice.
Organisation Of Memory In Linux (Part 8/15)
This tutorial is to explain about the organization of memory in Linux. Each and every application need some kind of memory for storing its data. In Linux applications access the memory space in a distinct manner. The memory-management unit (MMU) is the hardware responsible for implementing virtual memory. Memory is the most important part of a system.The concept of virtual memory is one of the very powerful aspects of memory management. Since the initial era of computers the need of memory more than the existing physical memory has been felt. Over the years, many solutions were used to overcome this issue and the most successful of them has been the concept of virtual memory.
Introduction to Linux – Create Thread (Part 15/24)
We know about thread in Linux. In this tutorial, I will explain how to create thread in Linux with the help of a programming example. Thread must be executed in process. It is much similar to a process. We can say that thread is light weight process and shares the same address space, data and attribute of process. Thread is single sequence stream within the process. It is like some mathematical or some small function of code which is run within the process. Refer to the tutorial Thread in Linux. You may refer to the tutorial how to make first C programming in Linux if you not aware of compilation and execution process. Here is tutorial with output showing alongside.
Introduction To Thread In Linux (Part 14/24)
In this tutorial, I will explain about thread which is an important topic in Linux. You must have heard about in multithreading in Linux. I will explain what the thread is and how it works. Let’s take the same example which I explained in tutorial Process in Linux If I want to make my passport but I don’t know what the process is, I will go to the inquiry window and ask about it. Process is nothing but carrying out a task. My task is to make passport and process is how to make passport. Now you must be wondering as to where the thread is.
Introduction To Linux-Communication Between Processes Through Pipe (Part 13/24)
Pipe is a one way communication of data between one process to another process. In the form of Interprocess communication (IPC), it is one type of communication. Refer to the tutorial Pipe in Linux before learning this one. Process creates a new pipe using pipe ( ) system call. It creates a pair of file descriptor: one for read channel and one for write channel. It can read from pipe by read ( ) system call with first file descriptor and can write to pipe by write ( ) system call with second file descriptor. It has half duplex pipes so each process must be closed before using another.
Introduction To Linux – Create Pipe With C In Linux (Part 12/15)
Pipe is one way communication of data between one process to another process. It is a form of communication called Interprocess Communication (IPC), Process creates a new pipe using pipe ( ) system call. It creates a pair of file descriptor: one for read channel and one for write channel. These file descriptors may pass through fork ( ) system call. It can read from pipe by read ( ) system call with first file descriptor and can write to pipe by write ( ) system call with second file descriptor. It is half duplex pipe so each process must be closed before using another.
Introduction to Linux Pipes (Part 11/15)
Various processes work in Linux system out of which some are dependent to each other or in other words one process uses some data of another process. Linux has a communication mechanism to communicate between two different processes called Pipe.Pipe is one way communication of data between one process to another process. it is a form of communication called Interprocess communication (IPC). Pipe transfers the output of one process to another which is accepted as an input. In computer, various processes run at the same time and require some data of another process or depend on another process. So, this data sharing between the processes is an important element of Linux.
Introduction to Linux Process (Part 9/15)
We always come across the term ‘‘Process’ in various Linux tutorials. In this tutorial, I will explain what the process is and how it works. If I want to make my passport but I don’t know what is the process. I will go to the inquiry window and ask about it. Process is nothing but carrying out a task. My task is to make passport and process is how to make passport.Process is an instance of program code in execution within the operating system. In computer machine, various applications run at the same time and they share the resource like printer, disk drive etc.
Kernel Architecture Of Linux (Part 7/15)
Kernel is a small and special code which is the core component of Linux OS and directly interacts with hardware. It is the intermediate level between software and hardware which provides low level service to user mode’s components. It is fully developed in C language and file system architecture Moreover, it has different blocks which manage various operations. .In this tutorial we will learn about kernel architecture of Linux.Kernel runs a number of processes concurrently and manages the various resources. It is viewed as a resource manager when several programs run concurrently on a system