Using three pins to drive three LEDs and read three buttons

Sometimes in more complex projects it is a waste to dedicate a line for every LED or button. If you thinking of selecting bigger microcontroller because you need additional pin to drive LED, think of smart way out. Francois AUGER & Philippe Fretaud have shared their technique of interfacing three LEDs and three buttons with three I/O pins. They used special Charlieplexing method of connecting all together and then wrote code piece to drive LEDs and read buttons. Three additional diodes allow reading buttons without affecting other components. Using three additional diodes is way more efficient than expanding number of pins. See video bellow of live action. Continue reading

Is The Time For Back to The Future

Did you know that a physicist, William Higinbotham, invented the world first remarkable computer video game, “Tennis for Two” in the year 1958? The purpose for this design is for an exhibition to improve the lackluster visitors’ day at the darn boring laboratory. This “Tennis for Two” concept is based on a tennis court, where its shown on an oscilloscope screen. The oscilloscope will allow the two players to toss the ball to each other continuously. There are two controls in each controller, where a button and a knob. You can hit the ball anytime you want, when the ball is on your side of the net by just hit the button. The function of the knob is to choose the angle you want the ball to be hit. Ok, it’s time for you to develop your “Tennis for Two”… Continue reading