Francois AUGER & Philippe Fretaud has posted this Design Idea on EDN that shows how to drive three LEDs and scan three tact switches with only three I/O pins of microcontroller. They have demonstrated the technique using the Atmel microcontroller (Arduino), and the technique could be useful for any low pin count devices where you can run out of I/O resources easily.
3 switches and 3 LEDs to 3 I/O pins
This nicely-built quiz game buzzer system is Arduino-based and captures the fastest player or “first to respond” out of four players.
Quiz game controller
A good friend of mine who’s a teacher was doing quizzes in her class making students compete to answer questions… resulting in them complaining they raised their hands before the others. I decided to give her this quiz show type buzzer for Christmas to solve her problems.
When one of the players press it’s button (the fastest player wins this), the led of the right colour lights up saying he’s in control… and no other buttons from the other players work, until the master of the game decides if the answer is good or not by pressing a little button on the main unit, giving a point or not to the player in control.
Infrared remote control for home appliances is a popular project among hobbyists and students. Smart Outlet is a similar project that provides an infrared controlled AC outlet to connect any electric appliance and has an integrated timer in it. The appliance can be turned on and off from several feet away using an IR remote. The device is Arduino-controlled and has a LCD display to provide a menu based interface to the user for its operation and settings.
Smart AC outlet
Noteu is an Arduino-based real-time display designed to notify the user of anything from the computer including the CPU speed, reminders for the meetings scheduled in the user’s Google Calender, emails, your shipping package update, and many more.
Noteu is one of the first customizable, hackable real-time displays that keeps youupdated in life, social media and business. Instead of needing to check multiple websites, apps or open any windows Noteu tells you what you need to know at a glance all in one place. With its easy to use Java application compatible on Windows, Mac and Linux you can choose amongst a wide range of updates and alerts with huge customization. Noteu being Open Source, based on the Ardunio platform, interfaceable with Java API’s and a simple serial protocol allows for infinite hacking.
This application note describes a DC-to-AC converter design, specifically targeted at converting highly variable energy from a solar panel into a form that can be directly connected to the power grid. This emphasizes on the control design and how PSoC 5LP is employed for a particular power topology.
Microinverter for solar power