Arduino

Founding in New York on 1 October 2016, Arduino LLC co-founder and CEO Massimo Banzi and Arduino SRL CEO Federico Musto announced the merger of the two companies, forming Arduino AG. Around that same time, Massimo Banzi announced that in addition to the company a new Arduino Foundation would be launched as "a new beginning for Arduino", but this decision was withdrawn later. In April 2017, Wired reported that Musto had "fabricated his academic record... On his company's website, personal LinkedIn accounts, and even on Italian business documents, Musto was, until recently, listed as holding a Ph.D. from the Massachusetts Institute of Technology. In some cases, his biography also claimed an MBA from New York University." Wired reported that neither university had any record of Musto's attendance, and Musto later admitted in an interview with Wired that he had never earned those degrees. The controversy surrounding Musto continued when, in July 2017, he reportedly pulled many open source licenses, schematics, and code from the Arduino website, prompting scrutiny and outcry. By 2017 Arduino 'AG' owned many Arduino trademarks. In July 2017 BCMI, founded by Massimo Banzi, David Cuartielles, David Mellis and Tom Igoe, acquired Arduino AG and all the Arduino trademarks. Fabio Violante is the new CEO replacing Federico Musto, who no longer works for Arduino AG. Post-dispute In October 2017, Arduino announced its partnership with Arm Holdings (ARM). The announcement said, in part, "ARM recognized independence as a core value of Arduino ... without any lock-in with the ARM architecture". Arduino intends to continue to work with all technology vendors and architectures. Under Violante's guidance, the company started growing again and releasing new designs. The Genuino trademark was dismissed and all products were branded again with the Arduino name. In August 2018, Arduino announced its new open source command line tool (arduino-cli), which can be used as a replacement of the IDE to program the boards from a shell. In February 2019, Arduino announced its IoT Cloud service as an extension of the Create online environment. As of February 2020, the Arduino community included about 30 million active users based on the IDE downloads. In October 2025 it was announced that Arduino has been acquired, for an as yet undisclosed amount, by the American semiconductor multinational Qualcomm. ==Hardware==

board with no Arduino logo Arduino is open-source hardware. The hardware reference designs are distributed under a Creative Commons Attribution Share-Alike 2.5 license and are available on the Arduino website. Layout and production files for some versions of the hardware are also available. Although the hardware and software designs are freely available under copyleft licenses, the developers have requested the name Arduino to be exclusive to the official product and not be used for derived works without permission. The official policy document on the use of the Arduino name emphasizes that the project is open to incorporating work by others into the official product. with an RS-232 serial interface (upper left) and an Atmel ATmega8 microcontroller chip (black, lower right); the 14 digital I/O pins are at the top, the 6 analog input pins at the lower right, and the power connector at the lower left. Most Arduino boards consist of an Atmel 8-bit AVR microcontroller (ATmega8, ATmega168, ATmega328, ATmega1280, or ATmega2560) with varying amounts of flash memory, pins, and features. The 32-bit Arduino Due, based on the Atmel SAM3X8E was introduced in 2012. The boards use single or double-row pins or female headers that facilitate connections for programming and incorporation into other circuits. These may connect with add-on modules termed shields. Multiple and possibly stacked shields may be individually addressable via an I²C serial bus. Most boards include a 5 V linear regulator and a 16 MHz crystal oscillator or ceramic resonator. Some designs, such as the LilyPad, run at 8 MHz and dispense with the onboard voltage regulator due to specific form factor restrictions. Arduino microcontrollers are pre-programmed with a bootloader that simplifies the uploading of programs to the on-chip flash memory. The default bootloader of the Arduino Uno is the Optiboot bootloader. Boards are loaded with program code via a serial connection to another computer. Some serial Arduino boards contain a level shifter circuit to convert between RS-232 logic levels and transistor–transistor logic (TTL serial) level signals. Current Arduino boards are programmed via Universal Serial Bus (USB), implemented using USB-to-serial adapter chips such as the FTDI FT232. Some boards, such as later-model Uno boards, substitute the FTDI chip with a separate AVR chip containing USB-to-serial firmware, which is reprogrammable via its own ICSP header. Other variants, such as the Arduino Mini and the unofficial Boarduino, use a detachable USB-to-serial adapter board or cable, Bluetooth or other methods. When used with traditional microcontroller tools, instead of the Arduino IDE, standard AVR in-system programming (ISP) programming is used. The Arduino board exposes most of the microcontroller's I/O pins for use by other circuits. The Diecimila, Duemilanove, and current Uno provide 14 digital I/O pins, six of which can produce pulse-width modulated(PWM) signals, and six analog inputs, which can also be used as six digital I/O pins. These pins are on the top of the board, via female 0.1-inch (2.54 mm) headers. Several plug-in application shields are also commercially available. The Arduino Nano and Arduino-compatible Bare Bones Board and Boarduino boards may provide male header pins on the underside of the board that can plug into solderless breadboards. Many Arduino-compatible and Arduino-derived boards exist. Some are functionally equivalent to an Arduino and can be used interchangeably. Many enhance the basic Arduino by adding output drivers, often for use in school-level education, to simplify making buggies and small robots. Others are electrically equivalent, but change the form factor, sometimes retaining compatibility with shields, sometimes not. Some variants use different processors, of varying compatibility. In addition to hardware variations, open source libraries have been developed to support Arduino hardware in EDA tools. One such project provides KiCad schematic symbols and PCB footprints for Arduino modules, expansion boards, and connectors, making it easier for engineers to integrate Arduino into their designs. Official boards The original Arduino hardware was manufactured by the Italian company Smart Projects. , 17 versions of the Arduino hardware have been commercially produced. File:Arduino316.jpg|Arduino RS232(male pins) File:Arduino Diecimila 6.jpg|Arduino Diecimila File:Arduino Duemilanove 2009b.jpg|Arduino Duemilanove(rev 2009b) File:Arduino UNO unpacked.jpg|Arduino Uno R2 File:Arduino Uno - R3.jpg|Arduino Uno SMD R3 File:Arduino Leonardo.jpg|Arduino Leonardo File:2x3 pin header on Arduino Micro.jpg|Arduino Micro (ATmega32U4) File:Arduino Pro Micro.jpg|Arduino Pro Micro (ATmega32U4) File:Arduino Pro.jpg|Arduino Pro(No USB) File:Arduino Mega.jpg|Arduino Mega File:Arduino Nano.jpg|Arduino Nano(DIP-30 footprint) File:LilyPad Arduino Main Board.JPG|Arduino LilyPad 00(rev 2007) (No USB) File:Arduino Robot Top.jpg|Arduino Robot File:Arduino Esplora.jpg|Arduino Esplora File:Arduino Ethernet Board.jpg|Arduino Ethernet(AVR + W5100) File:ArduinoYun.jpg|Arduino Yún(AVR + AR9331) File:ArduinoDue Front.jpg|Arduino Due(ARM Cortex-M3 core) File:Arduino Giga R1 WiFi.png|Arduino GIGA R1 WiFi (Dual core ARM Cortex-M7 + ARM Cortex-M4 cores + Murata 1DX) Shields Arduino and Arduino-compatible boards use printed circuit expansion boards called shields, which plug into the normally supplied Arduino pin headers. Shields can provide motor controls for 3D printing and other applications, GNSS (satellite navigation), Ethernet, liquid crystal display (LCD), or breadboarding (prototyping). Several shields can also be made do it yourself (DIY). File:Multiple shields stacked on an Arduino board.jpg|Some shields offer stacking headers which allow multiple shields to be stacked on top of an Arduino board. Here, a prototyping shield is stacked on two Adafruit motor shield V2s. File:Wingshield on Arduino - ARSH-05-WI.jpg|Screw-terminal breakout shield in a wing-type format, allowing bare-end wires to be connected to the board without requiring any specialized pins File:ARSH-09-DL 03.jpg|Adafruit Datalogging Shield with a Secure Digital (SD) card slot and real-time clock (RTC) chip along with some space for adding components and modules for customization File:Adafruit Motor Shield - ARSH-02-MS 01.jpg|Adafruit Motor Shield with screw terminals for connection to motors. Officially discontinued, this shield may still be available through unofficial channels. File:Front of the motor shield.jpg|The Adafruit Motor Shield V2 uses IC, requiring vastly fewer digital I/O pins than attaching each motor directly. File:Closeup of usbhost shield with jumper.JPG|A USB host shield which allows an Arduino board to communicate with a USB device such as a keyboard or a mouse ==Software==

A program for Arduino hardware may be written in any programming language with compilers that produce binary machine code for the target processor. Atmel provides a development environment for their 8-bit AVR and 32-bit ARM Cortex-M based microcontrollers: AVR Studio (older) and Atmel Studio (newer). The Arduino IDE supports the languages C and C++ using special rules of code structuring. The Arduino IDE supplies a software library from the Wiring project, which provides many common input and output procedures. User-written code only requires two basic functions, for starting the sketch and the main program loop, that are compiled and linked with a program stub main() into an executable cyclic executive program with the GNU toolchain, also included with the IDE distribution. The Arduino IDE employs the program avrdude to convert the executable code into a text file in hexadecimal encoding that is loaded into the Arduino board by a loader program in the board's firmware. Traditionally, Arduino IDE was used to program Arduino's official boards based on Atmel AVR Microcontrollers, but over time, once the popularity of Arduino grew and the availability of open-source compilers existed, many more platforms from PIC, STM32, TI MSP430, ESP32 can be coded using Arduino IDE. IDE 2.0 An initial alpha preview of a new Arduino IDE was released on October 18, 2019, as Arduino Pro IDE. The beta preview was released on March 1, 2021, renamed IDE 2.0. On September 14, 2022, the Arduino IDE 2.0 was officially released as stable. The system still uses Arduino CLI (Command Line Interface), but improvements include a more professional development environment and autocompletion support. The application frontend is based on the Eclipse Theia Open Source IDE. Its main new features are: • Modern, fully featured development environment • New Board Manager • New Library Manager • Project Explorer • Basic Auto-Completion and syntax check • Serial Monitor with Graph Plotter • Dark Mode and DPI awareness • 64-bit release • Debugging capability One important feature Arduino IDE 2.0 provides is the debugging feature. It allows users to single-step, insert breakpoints or view memory. Debugging requires a target chip with debug port and a debug probe. The official Arduino Zero board can be debugged out of the box. Other official Arduino SAMD21 boards require a separate SEGGER J-Link or Atmel-ICE. For a 3rd party board, debugging in Arduino IDE 2.0 is also possible as long as such board supports GDB, OPENOCD and has a debug probe. Community has contributed debugging for ATMega328P based Arduino or CH32 RISC-V boards, etc. Sketch A sketch is a program written with the Arduino IDE. Sketches are saved on the development computer as text files with the file extension .ino. Arduino Software (IDE) pre-1.0 saved sketches with the extension .pde. A minimal Arduino C/C++ program consists of only two functions: • : This function is called once when a sketch starts after power-up or reset. It is used to initialize variables, input and output pin modes, and other libraries needed in the sketch. It is analogous to the function . • : After function exits (ends), the function is executed repeatedly in the main program. It controls the board until the board is powered off or is reset. It is analogous to the function . ;Blink example Most Arduino boards contain a light-emitting diode (LED) and a current-limiting resistor connected between pin 13 and ground, which is a convenient feature for many tests and program functions. This program is usually loaded into a new Arduino board by the manufacturer. const int LED_PIN = 13; // Pin number attached to LED. void setup() { pinMode(LED_PIN, OUTPUT); // Configure pin 13 to be a digital output. } void loop() { digitalWrite(LED_PIN, HIGH); // Turn on the LED. delay(1000); // Wait 1 second (1000 milliseconds). digitalWrite(LED_PIN, LOW); // Turn off the LED. delay(1000); // Wait 1 second. }Sweep example Sweeping a servo with an Arduino means moving it back and forth across a specified range of motion. This is commonly done using the Servo library in Arduino. To sweep a servo with an Arduino, connect the '''servo's VCC (red wire) to 5V, GND (black/brown) to GND, and signal (yellow/white) to a PWM-capable pin (e.g., Pin 9). Use the Servo''' library to control movement. The code below gradually moves the servo from 0° to 180° and back in a loop. • include Servo myServo; // Create a Servo object void setup() { myServo.attach(9); // Attach servo to pin 9 } void loop() { for (int pos = 0; pos = 0; pos--) { // Move back from 180° to 0° myServo.write(pos); delay(15); } } Libraries The open-source nature of the Arduino project has facilitated the publication of many free software libraries that other developers use to augment their projects. Operating systems/threading There is a Xinu OS port for the ATmega328P (Arduino Uno and others with the same chip), which includes most of the basic features. The source code of this version is freely available. There is also a threading tool, named Protothreads. Protothreads are described as "extremely lightweight stackless threads designed for severely memory constrained systems, such as small embedded systems or wireless sensor network nodes. There is a port of FreeRTOS for the Arduino. This is available from the Arduino Library Manager. It is compatible with a number of boards, including the Uno. ==Applications==

• Arduboy, a handheld game console based on Arduino • Arduinome, a MIDI controller device that mimics the Monome • Ardupilot, drone software and hardware • ArduSat, a cubesat based on Arduino • C-STEM Studio, a platform for hands-on integrated learning of computing, science, technology, engineering, and mathematics (C-STEM) with robotics • Data loggers for scientific research • OBDuino, a trip computer that uses the on-board diagnostics interface found in most modern cars • OpenEVSE an open-source electric vehicle charger • XOD, a visual programming language for Arduino ==Simulation==

• Tinkercad Circuits - an analog and digital simulator supporting Arduino Simulation, which is commonly used to create 3D models ==Recognitions==

The Arduino project received an honorary mention in the Digital Communities category at the 2006 Prix Ars Electronica. ==See also==