While working on my Arduino magnet levitation (details here), I stumped upon some problems with the way the compiler, AVR GCC, handles multiplication. I had to implement optimized multibyte multiplication routines because Arduino in my project preforms some digital signal processing with 20kHz sampling frequency. Since I couldn’t find those routines online, I’m posting the code of some of them here I posted the code on GitHub at https://github.com/rekka/avrmultiplication.
Archive for the ‘Arduino’ Category
Arduino – AVR GCC multiplication
Posted in Arduino, AVR, tagged 16bit, 32bit, Arduino, AVR, AVR GCC, multiplication on March 18, 2009| 4 Comments »
Arduino Magnet Levitation – detailed description
Posted in Arduino, tagged Arduino, electromagnet, Hall effect sensor, levitation, magnet on March 17, 2009| 22 Comments »
Recently, I finished my first Arduino project, a magnet levitation device. It levitates a magnetic object under an electromagnet. What makes it different from similar projects is the position sensor for the feedback loop. I use a single Hall effect sensor placed directly on the bottom of the core of the electromagnet. This creates a problem of separating the electromagnet’s field from the levitating magnet’s field. Fortunately, this can be done in software by the microcontroller ATmega168 that is the heart of Arduino Duemilanove, the board that I use to control the levitation. This article gives a detailed description of the project together with source code at https://github.com/rekka/levitation, as I promised.
WARNING: This is an advanced project that requires quite a substantial amount of tweaking and understanding of the software internals to make it work. Please consider this post just a description of what I did. Furthermore, it is more than 3 years old and therefore hopelessly outdated; the software most likely needs nontrivial changes.
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My first Arduino project
Posted in Arduino, tagged Arduino, electromagnet, Hall effect sensor, levitation, magnet on March 2, 2009| 53 Comments »
It’s been only a couple weeks since I discovered Arduino, an open source microcontroller platform. I was looking for a cheap interface between my laptop and electronic circuits. Arduino with its price $35 and easy to use development environment was the best choice. So after getting my Arduino Duemilanove board and ordering some cheap components from AllElectronics, I had everything to start working on my old dream, making a magnet fly. Well, float.
Update: detailed description here
It took only a few days to figure out all the problems and my magnet floating device was born:
Floating a dart with Arduino
Here’s a video:
Modified Arduino library, Serial
Posted in Arduino, tagged Arduino, Serial on March 2, 2009| 10 Comments »
I needed a fast communication between Arduino board and my laptop while working on my first Arduino project. I was monitoring an analog input, the reading on a Hall effect sensor, and some other variables that my Arduino program was using, and that all at a high frequency, 10 kHz. That was producing around 50 kB/s of data that I had to push through the serial connection. I accomplished this finally by modifying the wiring_serial.c file in the Arduino library. You can dowload the modified here.(See below) See the instructions on how to use the file below.
Mekonikuv blog 