Selecting the right microcontroller for a product can be a daunting task. Not only are there a number of technical features to consider, there are also business case issues such as cost and lead times that can cripple a project. At the start of a project there is a great temptation to jump in and start selecting a microcontroller before the details of the system has been hashed out. This is of course a bad idea. Before any thought is given to the microcontroller, the hardware and software engineers should work out the high levels of the system, block diagram and flowchart them and only then is there enough information to start making a rational decision on microcontroller selection. When that point is reached, there are 1. Step 1 Make a list of required hardware interfaces. PIC usually pronounced as pick is a family of microcontrollers made by Microchip Technology, derived from the PIC1650 originally developed by General Instruments. Blog Entry Build Your Own Microcontroller Based PID Control Line Follower Robot LFR Second Part August 30, 2009 by rwb, under Robotics. One of the interesting. What`S A Microcontroller Pdf' title='What`S A Microcontroller Pdf' />Using the general hardware block diagram, make a list of all the external interfaces that the microcontroller will need to support. There are two general types of interfaces that need to be listed. The first are communication interfaces. These are peripherals such as USB, I2. C, SPI, UART, and so on. Make a special note if the application requires USB or some form of Ethernet. These interfaces greatly affect how much program space the microcontroller will need to support. The second type of interface is digital inputs and outputs, analog to digital inputs, PWMs, etc. These two interface types will dictate the number of pins that will be required by the microcontroller. Figure 1 shows a generic example of a block diagram with the io requirements listed. What`S A Microcontroller Pdf' title='What`S A Microcontroller Pdf' />Step 2 Examine the software architecture. The software architecture and requirements can greatly affect the selection of a microcontroller. How heavy or how light the processing requirements will determine whether you go with an 8. MHz DSP or an 8 MHz 8. Just like with the hardware, make notes of any requirements that will be important. For example, do any of the algorithms require floating point mathematics Are there any high frequency control loops or sensorsEstimate how long and how often each task will need to run. Get an order of magnitude feel for how much processing power will be needed. The amount of computing power required will be one of the biggest requirements for the architecture and frequency of the microcontroller. Step 3 Select the architecture. Using the information from steps 1 and 2 an engineer should be able to start getting an idea of the architecture that will be needed. Can the application get by with eight bit architecturesHow about 1. Does it require a 3. ARM core Between the application and the required software algorithms these questions will start to converge on a solution. Dont forget to keep in mind possible future requirements and feature creep. Just because you could currently get by with an 8 bit microcontroller doesnt mean you shouldnt consider a 1. Dont forget that microcontroller selection can be an iterative process. You may select a 1. ARM part works better. This step is simply to start getting an engineer to look in the right direction. Click below for more steps. Arduino Wikipedia. Arduino is an open source computer hardware and software company, project, and user community that designs and manufactures single board microcontrollers and microcontroller kits for building digital devices and interactive objects that can sense and control objects in the physical world. The projects products are distributed as open source hardware and software, which are licensed under the GNU Lesser General Public License LGPL or the GNU General Public License GPL,1 permitting the manufacture of Arduino boards and software distribution by anyone. Arduino boards are available commercially in preassembled form, or as do it yourself DIY kits. Arduino board designs use a variety of microprocessors and controllers. The boards are equipped with sets of digital and analog inputoutput IO pins that may be interfaced to various expansion boards shields and other circuits. The boards feature serial communications interfaces, including Universal Serial Bus USB on some models, which are also used for loading programs from personal computers. The microcontrollers are typically programmed using a dialect of features from the programming languages C and C. In addition to using traditional compiler toolchains, the Arduino project provides an integrated development environment IDE based on the Processing language project. The Arduino project started in 2. Interaction Design Institute Ivrea in Ivrea, Italy,2 aiming to provide a low cost and easy way for novices and professionals to create devices that interact with their environment using sensors and actuators. Common examples of such devices intended for beginner hobbyists include simple robots, thermostats, and motion detectors. The name Arduino comes from a bar in Ivrea, Italy, where some of the founders of the project used to meet. The bar was named after Arduin of Ivrea, who was the margrave of the March of Ivrea and King of Italy from 1. HistoryeditThe Arduino project started at the Interaction Design Institute Ivrea IDII in Ivrea, Italy. At that time, the students used a BASIC Stamp microcontroller at a cost of 1. In 2. 00. 3 Hernando Barragn created the development platform Wiring as a Masters thesis project at IDII, under the supervision of Massimo Banzi and Casey Reas, who are known for work on the Processing language. The project goal was to create simple, low cost tools for creating digital projects by non engineers. The Wiring platform consisted of a printed circuit board PCB with an ATmega. IDE based on Processing and library functions to easily program the microcontroller. In 2. Massimo Banzi, with David Mellis, another IDII student, and David Cuartielles, added support for the cheaper ATmega. Wiring. But instead of continuing the work on Wiring, they forked the project and renamed it Arduino. The initial Arduino core team consisted of Massimo Banzi, David Cuartielles, Tom Igoe, Gianluca Martino, and David Mellis,2 but Barragn was not invited to participate. Following the completion of the Wiring platform, lighter and less expensive versions were distributed in the open source community. Adafruit Industries, a New York City supplier of Arduino boards, parts, and assemblies, estimated in mid 2. Arduinos had been commercially produced,6 and in 2. In October 2. 01. Arduino announced its partnership with ARM Holdings ARM. The announcement said, in part, ARM recognized independence as a core value of Arduino. ARM architecture. Arduino intends to continue to work with all technology vendors and architectures. Trademark disputeeditIn early 2. Arduino project created a company, Arduino LLC,9 to hold the trademarks associated with Arduino. The manufacture and sale of the boards was to be done by external companies, and Arduino LLC would get a royalty from them. The founding bylaws of Arduino LLC specified that each of the five founders transfer ownership of the Arduino brand to the newly formed company. At the end of 2. Gianluca Martinos company, Smart Projects, registered the Arduino trademark in Italy and kept this a secret from the other cofounders for about two years. This was revealed when the Arduino company tried to register the trademark in other areas of the world they originally registered only in the US, and discovered that it was already registered in Italy. Negotiations with Gianluca and his firm to bring the trademark under control of the original Arduino company failed. In 2. 01. 4, Smart Projects began refusing to pay royalties. They then appointed a new CEO, Federico Musto, who renamed the company Arduino SRL and created the website arduino. This resulted in a rift in the Arduino development team. In January 2. 01. Arduino LLC filed a lawsuit against Arduino SRL. In May 2. 01. 5, Arduino LLC created the worldwide trademark Genuino, used as brand name outside the United States. At the World Maker Faire in New York on October 1, 2. Arduino LLC co founder and CEO Massimo Banzi and Arduino SRL CEO Federico Musto announced the merger of the two companies. HardwareeditThis sections factual accuracy may be compromised due to out of date information. Please update this article to reflect recent events or newly available information. October 2. Arduino compatible R3 UNO board made in China with no Arduino logo, but with identical markings, including Made in Italy text. Arduino is open source hardware. The hardware reference designs are distributed under a Creative Commons Attribution Share Alike 2. Arduino website. Layout and production files for some versions of the hardware are also available. The source code for the IDE is released under the GNU General Public License, version 2. Nevertheless, an official Bill of Materials of Arduino boards has never been released by Arduino staff. 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. Automated Activation Vermillion here. The official policy document on use of the Arduino name emphasizes that the project is open to incorporating work by others into the official product. Several Arduino compatible products commercially released have avoided the project name by using various names ending in duino. An early Arduino board1. RS 2. 32serial interface upper left and an Atmel ATmega. IO 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 ATmega. ATmega. 16. 8, ATmega. ATmega. 12. 80, ATmega. The 3. 2 bit Arduino Due, based on the Atmel SAM3. X8. E was introduced in 2. 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 ICserial bus. Most boards include a 5 V linear regulator and a 1. MHz crystal oscillator or ceramic resonator. Some designs, such as the Lily. Pad, run at 8 MHz and dispense with the onboard voltage regulator due to specific form factor restrictions. Arduino microcontrollers are pre programmed with a boot loader that simplifies uploading of programs to the on chip flash memory. The default bootloader of the Arduino UNO is the optiboot bootloader.