shiftIn() and shiftOut() commands in Arduino are, very loosely speaking, software implementations of SPI. Of course, SPI is much faster, but SPI can work only on some specific pins of Arduino. shiftIn() and shiftOut() can use any two GPIOs of Arduino (not some specific pins like SPI).Both shiftIn() and shiftOut() ... Read More

If there is an incoming pulse on a pin, and you need to measure the duration of the pulse then the pulseIn() function comes in handy.SyntaxThe syntax is −pulseIn(pin, value)Where pin is the number of the pin on which you wish to measure the pulse. The value is the level ... Read More

The tone function can be used to generate a square wave (50% duty cycle) of a specific frequency on a pin.SyntaxThe syntax is −tone(pin, frequency)pin is the pin number on which to generate the tone. The frequency is specified in Hz.This function can also take in a third optional argument ... Read More

The BasicLinearAlgebra library helps represent matrices and perform matrix math on Arduino. To install it, search for 'BasicLinearAlgebra' in the Library Manager.Once installed, go to: File → Examples → BasicLinearAlgebra → HowToUseAs the name suggests, this example shows how to use this library. While the comments in this example do ... Read More

The Complex library by RobTillart helps perform complex number math in Arduino. In order to install this library, you can search for 'Complex' in library manager. The library can be found on GitHub. (Pay attention to the Readme. The library doesn't compile for Due and Teensy 3.5. A solution is ... Read More

The Serial filtering library in Arduino helps you to apply some low pass filters and the median filter on any incoming data, to give you the filtered output. The GitHub repo of this library can be found here, and it is pretty detailed.In order to install the library, download the ... Read More

There are several libraries available which help you calculate the Fast Fourier Transform (FFT) onboard the Arduino. We will look at the arduinoFFT library. This library can be installed via the Library Manager (search for arduinoFFT).Once installed, go to: File→Examples→arduinoFFT and open the FFT_01 example.ExampleThis example first creates a sinusoidal ... Read More

The Gaussian Library by Ivan Seidel helps you implement Gaussian math, Kalman filters and moving averages in Arduino.To download this library, go to the Library Manager and search for 'Gaussian'. Install the library by Ivan Seidel.Once installed, go to: File → Examples → Gaussian, and open the GaussianRandomPlot example.ExampleNow, this ... Read More

The LinkedList library by Ivan Seidel helps implement this data structure in Arduino. A linked list contains a set of nodes wherein each node contains some data, and a link (reference) to the next node in the list.To install this library, go to Library Manager, and search for LinkedList.Once installed, ... Read More

Often, you are stuck on somewhere and don't find any relevant help from a Google search. In such cases, you can post your question on the Arduino Forum and ask for help from the vast Arduino community out there. Please make sure that you are not posting any duplicate topics. ... Read More