Archive for April 2011

Memory (Part 2)

Part 1, 2, 3, 4, 5, 6, 7 Recent works on Arduino drove me to embark more DSP (Digital Signal Processing) functions within Arduino. But I quickly went short of RAM and tried to find an easy and cheap way to add more bytes to the 2KB from my Arduino. After a quick search on Internet, I found this paper which gave […]

Memory (Part 1)

Part 1, 2, 3, 4, 5, 6, 7 The intention of this series of posts is to share a number of tips and tricks which will help developing quite big applications. I also plan to explain how I managed to increase the available memory for Arduino applications along with some application examples. I shall take the good ol’ ATmega328 as a reference […]


Arduino is so amazing! It is using an obsolete chip, it has not a regular shape, the pin stacks are not equally spaced. Many hackers proudly presented their own alternatives: some are really bringing something innovating while some others are poor clones. In spite of this ‘open’ competition, the Arduino alpha platform is not only […]

Sound capture (Part 4)

Part 1, 2, 3, 4, 5 So far, we managed to acquire a signal and to get its frequency spectrum. Now, we are interested in comparing it to a previously recorded spectrum. Again, because of the memory limitation of the ATMEGA 328, we will not record the reference spectrum in a Doubles vector. Instead, and because it’s far enough for […]

Sound capture (Part 3)

Part 1, 2, 3, 4, 5 Let’s have a look at the code structure for acquiring the signal and computing FFT. The big limitation here is memory. In spite of the ‘in place’ FFT calculation, at least 2 vectors of doubles are required occupying 2 times 4 bytes (for each double) times the number of samples. I built the acquisition […]