[English subtitles - Voice in spanish]
Demostración del potencial del Hardware libre y el software libre. Hemos usado el Arduino con un acelerometro conectado para controlar el Neverball. Un proceso de construcción bastante sencillo para obtener resultados espectaculares.
- Miguel - desarrollador
- David - Camara
More info in:
I am Miguel and now you will learn what can you make with free software and free or open hardware. In particular, I´m going to use Arduino model Duemilanove, one accelerometer, and the Nevervball´s videogame modified source code.
Well, first of all, I show you the final result, spectacular? Isn´t it?
The physical elements which compose the system, or invention, or game perifecal are:
-an accelerometer of three axes, although I only use two axes, the X axis and Y axis.
-an arduino Duemilanove, but others arduino models are compatible too.
-electric cables and a protoboard.
-a usb cable to pc, this cable behaves as serial.
And the software elements are:
-a GNU/Linux. Why? Because it's free software and it gives more advantages.
-the arduino IDE.
-the program I made for arduino, which reads the accelerometer and sends the datas to USB.
-and another programm I made in PC, this reader the serial USB
Well, I´m going to explain carefully how it works.
I have connected the accelerometer to arduino in this way: the five volts and ground into the pins five volts, and ground in arduino, and the accelerometer pin of axis X into the pin analog in number W and the pin axis Y into K analog in pin of Arduino. And, finally, I connect the Arduino to USB for power supply, upload the program and send the data.
The program which runs in arduino it's the 0.2 version that the acceleration of two axis encode in one character to send, and the previus version send one character for each axis, but it had problems in the PC reading proccess. In the setup function make a translation table with forty nine print characters organized in array seven per seven because before the program read seven grades of tilt in each axis and use the table for encode in one character for send.
The PC reader program is writen in shellscript, like the code of Arduino, and is the 0.2 version. This programa only reads one character in the serial port, it creates the inversed translation table, the program translates in two axes again and sends for each axi as press key in active aplication, neverball.
And the source code of neverball is modifed for get more new keys and use as joystick moves with different tilk degress for each new key.