DSP Forum - Recent Threads

Algo for rms computation?

ggabe — Wed, 19 Jul 2023 05:38:04 GMT

I’m entertaining a true rms computation on MSPM0G3507 for the 10Hz…100KHz range.

The MCU is limited to 32K RAM, so I’d change the sampling frequency if I can determine the signal is periodic and in the lower frequency range.

Is there any algorithm that aims capture N periods of a periodic signal?

Should I be better of by going into frequency domain with a proper window function, and possibly trying multiple sampling rates to choose the proper range?

good FFT library for a non-ARM microcontroller

Jan Cumps — Sun, 16 Jul 2023 19:03:47 GMT

I'm planning to make an FFT project for a Renesas RX microcontroller. Renesas provides a binary lib that works with their proprietary toolchain. It doesn't support GNU/GCC.

Do you know good C or C++ microcontroller-scale libraries that would be portable to another platform? Preferably one you have good experience with.

I've done this before for the ARM CMSIS DSP FFT lib, together with martinvalencia . But that was for a TI Hercules, an ARM controller.
The RX platform that I'm targeting isn't ARM.

If you 've used a good library that you think is portable, let me know....

What is the difference between the two https://www.element14.com/community/docs/DOC-87009 and. https://www.element14.com/community/docs/DOC-40513

arjun619 — Fri, 03 Nov 2017 06:30:44 GMT

What is the difference between the two https://www.element14.com/community/docs/DOC-87009 and. https://www.element14.com/community/docs/DOC-40513

Arduino + Audio DSP = Aida DSP

max.payne86 — Wed, 16 Dec 2015 15:51:08 GMT

Hi,

Aida DSP is a solution

for starting doing audio dsp projects faster.

https://github.com/AidaDSP/AidaDSP/wiki

during project developement I focused on available applications

so you'll find a lot of open source examples

ready to run on the Aida DSP board.

A library for controlling DSP in real time with Arduino

is available, on github repo.

If you are interested, contact us

max@aidadsp.com

Thank you

Filter IC sample rate vs. cutoff frequency

ocwo92 — Wed, 02 Dec 2015 10:01:05 GMT

I'm looking at the LTC1064 and its family members of low pass filters and the datasheets confuse me.

On most of these ICs, you set the cutoff frequency by selecting a clock frequency. According to the datasheets, most of the ICs now sample the signal at a sample rate of twice the cutoff frequency, i.e., at the Nyquist limit, to avoid aliasing.

To me this seems to defeat the very purpose of the low-pass filter. The purpose of low-pass filtering a signal prior to sampling it is to enable us to safely use a sample rate at the Nyquist rate without risking aliasing(*). However, by sampling first and filtering afterwards, aliasing will almost certainly occur.

What am I missing?

(*) Nit-picking: yes, I am aware at the Nyquist rate you will incur some aliasing unless the signal is perfectly band-limited to half the Nyquist frequency so in practice either a lower cut-off frequency or a higher sampling rate should be selected.

firmware update for mp3 decoder chip

dr.akshay_1980@yahoo.com — Thu, 10 Sep 2015 17:33:24 GMT

Hi,

I would like to know that how to update the firmware or write firmware for LC2093-B (heart for chinese mp3 player) based devices using any kind of specials tools which the manufacturer/developers use?

How can I write the firmware from scratch if possible? I am keen to work on this simple decoder which is low cost, low voltage chip for my future projects.

I could not find its datasheet anywhere, no technical specification is available.

Any help in this regard would be appreciated.

Akshay

Digital Signal Processing

martinvalencia — Sun, 30 Aug 2015 21:00:27 GMT

I started my thesis project for college, I have little experience in the area of digital signal processing, but enough to start a project; I have a question I could not answer.

How to read the magnitude of a Fourier transform, when using the Fourier transform, to calculate the magnitude of the imaginary and real parts, not achievement convert data to dB?

if there is any reference to this article serious issue of great help if you can share.

The FFT libraries I'm using are these:

Frequency Bin Example

Traitement du signal : dsPIC33EV 5V / 70MIPS haute fiabilité

MicrochipRTCfr — Sat, 29 Nov 2014 10:34:59 GMT

La nouvelle famille dsPIC33EV améliore l'immunité au bruit grâce à son fonctionnement sous 5V complet (périphériques digitaux et analogiques).

Ce produits sont disponibles en gamme standard -40 à +85C, en gamme étendue -40 à +125C et aussi en gamme très haute température -40C à +150C pour l'automobile (AEC-Q100 grade 0)

La correction d'erreur (ECC) sur la mémoire FLASH, permet de corriger en temps-réel les bits erronés permettant d'augmenter la fiabilité, la sécurité et la durée de vie du système. Le Deadman timer (DMT), le CRC et le Windowed Watchdog Timer (WWDT), l'oscillateur de backup et la conformité class B permettent d'utiliser ces dsPIC dans les applications Safety-critical.

Leur double banque de mémoire Flash permet de bootloader sans arrêter ou ralentir l'application.

Destinés aux applications industrielles et automobiles, les dsPIC33EV intègrent un convertisseur A/N 12bits, DAC 7bits des PWM pour le contrôle moteur / les alimentations, des AOP (jusqu'à 4), un contrôleur CAN, des UARTS/LIN, des canaux I2C/SPI ainsiq qu'un grand nombre de timers.Le protocole SENT pour l'automobile est également supporté.

Le bloc périphérique CTMU dédié à la gestion de claviers capacitifs ou aux capteurs capacitifs offre une grande résolution de mesure et une très grande dynamique permettant la gestion de signaux de très faible amplitude.

Les canaux de DMA permettent aux périphériques d'accéder à la mémoire RAM sans exécution logicielle et réduisent ainsi la charge CPU.

Compatibles avec les dsPIC33EP et les dsPIC30 au niveau logiciel, ils permettent une migration rapide des logiciels existant tout en offrant la compatibilité 5V et l'accès aux fonctions robustes pour les environnement bruités ou à fiabilité élevée

Le kit d'évaluation DM330018 permet de démarrer instanément le dévelopment logiciel. Il est bien sûr compatible avec MPLAB X.

Le compilateur XC16 et MPLAB X peuvent être téléchargés gratuitement sur 3 plateformes : Linux, MAC OS et WIndows au choix de l'utilisateur.

Les échantillons sont disponibles immédiatement.

Attachments:

community.element14.com/.../Microchip_5F00_catalogue_5F00_formations_5F00_WEB_5F00_Q1A_5F00_2014_5F00_140307.pdf

Microchip_catalogue_formations_WEB_Q1A_2014_140307.pdf

Playing of audio/video files- DSP(Digital signal processor) vs Specific software application

dr.akshay_1980@yahoo.com — Mon, 24 Nov 2014 11:40:20 GMT

I would like to ask that while playing any music formats such as .mp3/aac/wma or any other known audio formats and avi,flv,mpeg which are video formats, Is specific DSP responsible for their encoding and playing the content or our software application is responsible for playing the type of formats for music files.

E.g. If my cellphone is not able to .flv file which thing is responsible for it? ( My mobile DSP or My mobile operating system's software application).

450MHz Shark DSP Dev-kits

Kilohercas — Thu, 26 Dec 2013 12:30:35 GMT

Hello, does any one are interested in Analog devices Shark development kit ?

Basically it is ADSP-21489 floating point DSP running at 450MHz ( possible to 700MHz overclock) with all pins connected to header (except single UART for debugging and boot pins for spi flash since i am using dual channel FT2232 for debugging/programing)

I made Labview program that can program external SPI flash with FT2232D from Labview by using loader file generated inside Crosscore or VisualDSP++ IDE. This can be very high performance calculation engine for demanding applications. I can do single point DFT with 128 array at 2MHz repetition rate, while ARM Cortex M4 (STM32F407 running 250MHz can only do 50KHz !! )

Here is what Shark DSP can do in native calculation (Mandelbrot fractal in f32 )

www.youtube.com/watch

At the moment i have single unpopulated board , but can order more if demand is big. With additional cost i can buy all parts, assemble and ship it as full development kit.

Circuit Diagram is needed for the following features

Former Member — Mon, 03 Dec 2012 14:52:41 GMT

I have to design a crcuit which will have following features:

I/P: X15 X14 X13... ... ...X0 bits

O/P: 1, when I/P bit sequence has 3 consecutive ones

or atleast 3 consecutive ones.

Would u pls show me the circuit diagaram needed for this requirement?

thanx in advance

Industry’s Smallest 800-MMAC DSP also Features Low Power

GardenState — Wed, 15 Sep 2010 00:44:49 GMT

Analog Devices today introduced the Blackfin ADSP-BF592 digital signal processor (DSP) with 800 MMACs/400MHz of performance for $3 (in 10K quantities). Featuring an active power draw said to be as low as 88 mW at 300MHz (and standby power of less than 1mW) the DSP comes in a 9 mm x 9 mm 64-lead LFCSP package, making it suitable for power-constrained, small form-factor compute-intensive applications that operate without the need for external memory or executable flash.

The ADSP-BF592 is the low cost entry point into the Blackfin portfolio of processors. It has a peripheral set including two serial ports (SPORT’s), a PPI, two SPI’s, four general-purpose counters and a factory-programmed instruction ROM block containing the VDK RTOS and C-runtime libraries.

An EZ-KIT Lite® evaluation kit for the Blackfin BF592 is available for $199, and includes an evaluation suite of ADI’s VisualDSP++ development environment with the C/C++ compiler, assembler and linker.

Dsp application

kemmi — Fri, 21 Aug 2009 00:55:53 GMT

Attached file include below application:

1:     High Performance Modems for Plain Old Telephone Service (POTS)
2:     Remote Access Server (RAS) Modems
3:     ADSL (Assymetric Digital Subscriber Line)
4:     Digital Cellular Telephones
5:     GSM Handset Using SoftFone™ Baseband Processor and Othello™ Radio
6:     Analog Cellular Basestations
7:     Digital Cellular Basestations
8:     Motor Control
9:     Codecs and DSPs in Voiceband and Audio Applications
10:     A Sigma-Delta ADC with Programmable Digital Filter

Attachments:

community.element14.com/.../Dsp-application.pdf

Dsp application.pdf

TMS320F2812 CMD file detail configuration

kemmi — Thu, 20 Aug 2009 01:15:08 GMT

Attached file include TMS320F2812 CMD configuration.

Attachments:

community.element14.com/.../CMD_8765F64E4D916E7FE68BE389_.pdf

CMD文件配置详解.pdf