Choosing a DSP for Audio Spectrum Display - Page 1
Forum section: electronics / general

author: HamiltonHipster
author_rank: Contributor
timestamp: October 07, 2013, 10:54:47 am
content: Hello eevForum,I'm trying my hand at designing a 10 band Audio Spectrum, using DSP.I have already designed the 11 x 10 display logic for an ATF2500c i have lying around, and i want to communicate to it using SPI.Does anybody know of any (relatively cheap) audio DSP i can use to sample, process, and send out using SPI?DIP or surface mount, i don't mind.Cheers

author: HamiltonHipster
author_rank: Contributor
timestamp: October 07, 2013, 11:29:52 am
content: Wow fast response!These chips look good, Thanks Pippy.I will need to do a lot of datasheet reading to figure out which one will be adequate... I really just want a light show on the front of an ampThanks a bunch

author: HamiltonHipster
author_rank: Contributor
timestamp: October 07, 2013, 12:41:11 pm
content: I have book marked the chips you've found for me, they quite powerful.I did have ideas of making 80 or 160 band displays, but a simpler 10 band one will get me in the game. I'm taking classes for DSP at the moment, and i'm working on this as a side project. An AVR looks like the way to go for a simple project like this.Thanks for being patientFFT = Fast Fourier Transform?

author: dannyf
author_rank: Super Contributor
timestamp: October 07, 2013, 12:47:58 pm
content: QuoteThat would be SFT: slow fourier transformation,Seriously, it has been done with 8051s - but that chip has a significant math advantage over most 8-bit mcus.

author: ve7xen
author_rank: Super Contributor
timestamp: October 07, 2013, 05:37:18 pm
content: Quote from: dannyf on October 07, 2013, 12:47:58 pmhttp://elm-chan.org/works/akilcd/report_e.html

author: elektronchika
author_rank: Contributor
timestamp: October 07, 2013, 07:46:31 pm
content: Texas Instruments Tiva C Launchpad - $13 with free worldwide shipping

author: tehmeme
author_rank: Regular Contributor
timestamp: October 07, 2013, 08:08:16 pm
content: This may be a little overkill for your needs, but have a look at this thread:https://www.eevblog.com/forum/projects/3d-pov-display-full-design/msg246708/#msg246708and his youtube channel is:https://www.youtube.com/user/jfghvljgvktgvlkhvgyv/videosThis is his second thread showing a time lapse of his PCB construction for this project:https://www.eevblog.com/forum/projects/pcb-construction-time-lapse/msg275174/#msg275174

author: maros
author_rank: Contributor
timestamp: October 07, 2013, 09:04:33 pm
content: If you want to start doing projects related with DSP, I'd reccomendC2000 Piccolo LaunchPad. It's cheap and have it's own integrated isolated XDS100 JTAG emulator on board. You could download complete IDE for it (Code Composer Studio) and lot of example projects.

author: HamiltonHipster
author_rank: Contributor
timestamp: October 08, 2013, 06:57:23 am
content: Good stuff!Thanks a lot guys!When i've finished i'll post a thread on how it went

author: tszaboo
author_rank: Super Contributor
timestamp: October 10, 2013, 05:31:51 pm
content: What is usually forgotten, that audio Spectrum is displayed in LOG scale. so if you want to display 20Hz and 16000 Hz, than you need to make a 8000 point FFT at least, and throw away (ok, not exactly) most of the points. But huge computing power is required. That AVR display is completely linear, in both ways. It is still impressive, but completely useless.

author: nctnico
author_rank: Super Contributor
timestamp: October 10, 2013, 06:50:05 pm
content: Goertzel is the magic word here.

author: kripton2035
author_rank: Super Contributor
timestamp: October 10, 2013, 07:20:47 pm
content: Microchip 16-bit Embedded Control Design Contest, entry MT1750with a dsPIC30F6012Ahttp://www.circuitlib.com/index.php/library/product/9-audio-spectrum-analyzer/category_pathway-24