The operating system (OS) acts as a manager for all the I/O device, memory, CPU, file storage resources and allocates them to specific programs and users, whenever necessary to perform a particular task. Therefore, the operating system is the resource manager that means it can manage the resources of a computer system internally.The operating systems are important and should be correctly used when writing the user applications. Large and complex systems have high economic impact and this result in interesting problems of management.Few systems are involved in the design and implementation of OS but, nevertheless many general techniques have to ... Read More

A modern computer consists of the following −One or more processorsMain memoryDisksPrintersVarious input/output devicesSo, in order to manage all these components, we require a layer of software in the computer system, that layer we call the Operating System (OS).DefinitionAn Operating System is a program that acts as an intermediary or interface between a user of a computer and the computer hardware. It is the most important type of system software in computer systems.Without an operating system the user cannot run application programs on the computer system.Generally, a computer system consists of four main components, called hardware, application programs, operating system, ... Read More

A computer system consists of many resources like hardware and software, which are useful to complete a task. The common required resources are input/output devices, memory, file storage space, CPU etc.The operating system acts as a manager for all the above resources and allocates them to specific programs and users, whenever necessary to perform a particular task. Therefore, the operating system is the resource manager that means it can manage the resources of a computer system internally. The resources are processor, memory, files, and I/O devices.An operating system is the interface between the user and the machine. Before there were ... Read More

The equivalent of deep sleep in Arduino would be the Power Down mode, which consumes the least power out of all the sleep modes. While this has already been covered in another article, but for the sake of completeness, here’s a brief on the sleep modes in Arduino.Arduino’s microcontroller, ATmega328P has 6 sleep modes, of which 5 are available with the avr/sleep.h library.Idle modeADC Noise ReductionPower-downPower-saveStandbyExtended StandbyEach mode has different wake-up modes and different power consumption.The Idle mode is easiest to wake up from and the Standby and Power down mode is the most difficult to wake up from (you ... Read More

In this article, we will, as the title suggests, make the Arduino sleep, and wake it up using an interrupt. Arduino’s microcontroller, ATmega328P has 6 sleep modes, of which 5 are available with the avr/sleep.h library. Each mode has different wake-up modes and different power consumption.Arduino’s microcontroller, ATmega328P has 6 sleep modes, of which 5 are available with the avr/sleep.h library.Idle modeADC Noise ReductionPower-downPower-saveStandbyExtended StandbyEach mode has different wake-up modes and different power consumption.The Idle mode is easiest to wake up from and the Standby and Power down mode is the most difficult to wake up from (you can only ... Read More

The Time library provides you with timekeeping functionality on the Arduino. The latest version of the library is documented here.To install it, search for Time in the Library Manager and install the library by Michael Margolis.You’ll have to scroll a bit to find this library.Once the library is installed, if you go to File → Examples → Time, you will be able to see several examples of integrating this library with various sources: GPS, NTP, RTC, etc.The basic idea is that you can set time using the functions −setTime(hours, minutes, seconds, days, months, years);OR, setTime(t);where t is the special time_t ... Read More

An RTC module keeps track of time once an initial time input is provided to it. This input can come from several sources (NTP, GPS, etc.). The RTC module usually comes with its own crystal oscillator, and even its own battery, so that the timekeeping continues, even if there is a power disturbance on the Arduino.Circuit Diagram −We will use the DS3231 module. It uses I2C for communication (SDA and SCL lines). The circuit diagram is shown below −As you can see, the Vcc pin of DS3231 is connected to 5V, GND to GND, SDA to A4 (SDA) and SCL ... Read More

Follow the steps given below to browse Arduino libraries by category on Arduino website −Go to http://arduino.cc/Click Documentation → ReferenceClick Libraries from the left menu.The libraries can now be found in the categorized form on this pageClick the category of your interest and explore the available libraries.

goto is a control structure in Arduino, like in C, and it is used to transfer the program flow to another point in the program. It is highly discouraged, as many programmers agree that you can write every algorithm you want without the use of goto.Excessive use of goto makes it very difficult to debug programs, or, in some cases, creates program flows which are impossible to debug. It is assumed that you will read further only if you absolutely have to use goto.SyntaxThe syntax for using goto is −goto label; label:    //statementsExampleThe following example demonstrates this −void ... Read More

The reference (&) and dereference operators (*) in Arduino are similar to C. Referencing and dereferencing are used with pointers.If x is a variable, then its address is represented by &x.Similarly, if p is a pointer, then the value contained in the address pointed to by p is represented by &p.Examplevoid setup() {    // put your setup code here, to run once:    Serial.begin(9600);    Serial.println();    int x = 10;    int *p;    p = &x; //p now contains the address of x    Serial.print("The value stored in the address pointed by p is: ");Serial.println(*p); } ... Read More