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DTMF

hey guys, i'm new to the electronics field and need some help. i'm doing this proj of dtmf decoder..can anybody please tell me how exactly to interface the telephone line and the dtmf chip? thanks ...

DTMF Detection using Goertzel Algorithm

Hi, I am new here and to the DTMF. I need some clarifications.... 1) What must be the minimum energy level for DTMF signal. 2) How can i validate the DTMF signal after Goertzel Algorithm. can anyone help........ -Raghu ...

Teager-Kaiser Energy Operators of dtmf

TKEO on DTMF is producing a sinusoidal signal, and amdf on this generated perhaps will give a constant local minima :-( I am still trying to do a narrowband detection cheaply. Can any body has already observed TKE0 on DTMF signal ? Regds, d.pal ...

DTMF using MATLAB

Can any body help me in writing code of following problem in MATLAB :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::= =AD:::::::::::::::::::::: Design digital oscillators for DTMF frequencies at sample rate of 22500 sp/sec Generate a seven digit DTMF using Digital...

interfacing

is there any important point to be considered while interfacing the DTMF chip to the phone line? i 'm currently working on a DTMF decoder proj and got stuck at the interfacing between the telephone line and the DTMF MT8870 and the interfacing between MT8870 and PIC18F452. somebody pls suggest m...

DTMF decoder for PC

Hi, can anyone recommend a C or C++ package for PC decoding DTMF digits from a wave file or soundcard? Thanks, John ...

SHARC dtmf decode source

Does anyone have an example of dtmf decoding using a SHARC dsp? How about a Goretzel routine written for the SHARC? Thanks for your help. ...

Decoding DTMF

hi all, i need to write an application that listen for DTMF tones from standard audio input (from the mic) and execute an action depending on the digit extracted from the DTMF tone. Unfortunaly i have short time to set up this application and i'm really new to this kind of problem (sound analis...

DTMF decoder

Hi everyone, I am designing a dtmf decoder using the Goertzel algoritm, the problem is that I have +/-5% error on my sampling rate timing. Does anyone know if this is going to be a problem when calculating the results? Thanks in advance ivan ...

DTMF detector

Hi people, I´m trying to develop a DTMF detector using goertzel algorithm in Blackfin BF 532. My problems are: 1) Wath kind of filter may I use? 2) What range may it has? Kind regards Sergio Fink ...

DTMF detection within PCM audio

Hi, I am trying to implement an IVR functionality as a part of Windows application. I don't want to use TAPI. So, I am looking for a source code detecting DTMF signals within a PCM audio stream. Can anybody help me on this? Any references? Thanks in advance, Mark ...

Looking for DTMF-detector test suites

Hi, Where can I get a copy of the Mitel, Bellcore or other test tapes? Are there any public-domain DTMF test suites available? Thanks, Scott ...

Re: Tone detection (NewBie)

On 21 Jul 2004 14:52:54 -0700, extenddos@yahoo.com (dosextender) wrote: > > How many different tones might there be? > > In the beginning I expect to have 2 tones. (Possibly more later on) > > > Do you need to distinguish between them? > > Yes most definitely. > > > Do you need to...

Newbie Q: Goertzel threshold testing, speech detection

Hi, I'm currently using the Goertzel algorithm to do DTMF detection. Currently, I get the magnitude for each DTMF frequency, save the sums of the magnitudes that correspond to each number, then I assume whichever sum is the highest must the be the most likely DTMF key. This works, but seem...

Mitel CM7291 DTMF talkoff test tape

I have 3 original Mitel CM7291 DTMF talkoff test tapes for sale. Contact me directly: sales @ vconsole dot com Dmitry ...

Goertzel to recognize DTMF in Java

Hello, Im working on the recognition, from a wav file, of DTMF tones. The program is being done in Java. What i do is open the file, get the info in a byte array and pass it to a double array. Now im not sure what to do. Ive heard that the best algorithm for this task is Goertzel, but I have...

DTMF decoder

hello, I need to make a dtmf decoder using java. And it has to be decoded using the pc sound card. Right now all i can do is connect 2 phones through my modem. Any suggestions on how do i map the modem sound onto my pc sound card? My modem does not have a connection for a jumper. So i...

Re: Volume

brettccl...@gmail.com wrote: > Hello All, > I'm currently using the Goertzal algorithm to find a couple frequencies > in some audio samples. However, how am I supposed to deal with volume > differences? On occasion, the tones are quieter and thus don't seem to > be picked up by the dec...

min. sampling frequency of DTMF decoder

Given the following frequencies in DTMF : lfg = [697 770 852 941]; % Low frequency group hfg = [1209 1336 1477]; % High frequency group what is the min. sampling frequency and the number of samples required (using FFT) to detect the keys? I tried Nyquist sampling frequency (2*max f...

DTMF Detection

I am trying to develop an application(in C#) that will be able to decode DTMF tones coming in through my microphone input. My main focus right now is to detect a dialtone. I am in no way familiar with any of the algorithms or formulas used for any of this stuff. I have spent a week searching and ...

Re: ULAW ALAW and RFC2833

Phil Frisbie, Jr. wrote: > stawdema@yahoo.com wrote: > > > I understand the need for using 2833 while using compression codecs. I > > was wondering if anyone could tell me why 2833 is used with ULAW/ALAW. > > > I hope this is not a homework question ;) > > Think event speed and...

DTMF encoder for TMS C 62xx

Hi all, I'm a bachelor student and I'm trying to write a dtmf enc / dec for the T.I. TMS c62 board. I already developed my c code for the encoder and actually working on the decoder. I'm writing this post because i can't make my encoder work on the target board.The program does compile but ...

DTMF and goertzel

Hi, i am trying to implement DTMF detection by using goertzel algorithm But i have meet some questions: 1. How can i determine coefficient for filter frequency? I know that coefficient= cos(2*pi*k/N)*32768, where k= (N*fi)/fs , fi= filter frequency fs= sample frequency for ex...

Re: Is there a software FSK encoder API for PC using no addtl hardware?

tomerp55@hotmail.com (Tomer) wrote in message news: ... > Hi All, > Does anyone know if such a thing exists or do I have to code it up > myself? Yes... ;-) Go to my site and look for Objective Real-Time Software on the ADSP21xx, online tutorial. It has a chapter on generating DTMF t...

DTMF Detection

Hi all. I´m trying to implement the goertzel algorithm in C#, but without good results. The steps I'm trying are: 1) I perform a goertzel for each of the frequencies in the table (lows and highs). For Low ones I use N=212 and 106 for High ones. 2) Save the highest ones (Low and High) 3) Th...

Somewhat off-topic post: DTMF transfer with wireless codecs

I am researching the capability of various wireless speech codecs in handling DTMF digits. Since these codecs are typically rather low rate, one would expect that their ability to reliably transmit pure tones, music and/or multitone digits would be compromised. I see in the SMV codec specifica...

Re: DTMF detection and samples

Thanks. This is the part I understand. The one I can´t get is about reading the samples, I mean, I can read N bytes from buffer, but puting it in a Byte array, so each sample will be of 1 byte(?). I need to read at least 4 samples of 2048 bytes each. I don´t know how to do this, but I think this wou...

dsPIC and PSTN .. DTMF, Caller ID and QAM modem tons

I have been working in a project to decode modem signals: DTMF tones, Called ID and modulate signals in low rate QAM (until 14400). I do have few knowledge in eletronics, so i decide to buy a Mikroe.com =B4s development kit to help me in the basics...Although this kit doesn't have any interface ...

Re: Finding certain frequencies in an audio signal

Rune Allnor wrote: > ... I haven't used Goertzel's algorithm > myself, but I can't really see that it fits in this scheme. Why not? It's pretty standard for DTMF. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯...

Re: selecting the best chip

Hello Vladimir, > > There is no need for DSP. Any microcontroller will do the DTMF detection > algorithm. The lazy folks can use the traditional 8870 clones. > For those interested in how to squeeze that into a bare bones uC look at TI app note SLAAE16. It's under MSP430. Regard...

DTMF detection with Goertzel

Hello, I am wondering what would be the smallest number of sample that one can use with Goertzel algorithm to detect DTFM. Assuming 8Ksps. Can I use 40 samples? Can I use 160 samples? Should it be an even number? What is the restriction on this matter? Best regards ...

Goertzel algorithm:Overflow occured in Call Progress Detection!

Dear friends I need to implement a call progress tone detector using goertzel algorithm. To avoid strong signal inputs to the Goertzel filters, additional gain control is used to prevent early overflow: ; Control gain of the input sample x(n) ; On a 32 samples length buffer of input samples...

GOERTZEL ALGORITHM VERIFICATION

Hi all, I want to implement Goertzel algorithm for DTMF detection, I want to know the basic things to consider to implement it i.e should i directily Choose N(sample length)=205 (as more optimsed) or which factors should be taken in acccount for it. Also how should i test my code i.e ...

Re: Question in Detection

Randy Yates wrote: > Suppose we have a signal y(t) that is composed > of white noise of unknown variance n(t) and potentially > a sinusoid of known power s(t) and known frequency > F, so that > y(t) = s(t) + n(t). > The object is to detect the presence (or not) of > s(t). ...

Re: Call progress tone detection

L Hao wrote: > Hello all, > > I need to develop a tone detection algorithm to detect call progress tones, > specifically busy tone, congestion tone, and error tone(howler tone) sent > from CO through subscriber loop so that we can be more intelligent about > some of the problematic hang...

DTMF with Goertzel algoritm

Hi all, i'm working on a digital auto.responder with voice modems. I need to recognize DTMF so i use Goertzel Algoritm to detect it. Here's the code: /* TestDTMF * Copyright (C) 2004 Pinassi Michele * * This software is free software; you can redistribute it and/or * modify it under the...

Re: OT: Where did you get your start?

I have started working with the DSP because of the practical needs. We had a project which could be nicely implemented with the DSP, and someone had to do it. At that time I was quite experienced with the analog and the embedded stuff and could do basic things like DTMF decoding with a m...

Re: Food for thought.

Hello Martin and others, A related to engineering book is entitled "Hydrogen". It details the experimments that led to all of the refinements of quantum mechanics (atomic). The neat thing is the simplest of atoms led to such a wealth of knowledge[1]. The chapters on the experiments of I. I. Ra...

Re: DTMF detection through Sound Card

dkurman wrote: > Tim: I already tried this. I have a tone generator by soft and the goertzel > did work. But when I change to detect through sound it doesn´t work any > more. I think the problem is about the sampling and buffering or maybe > when I convert from byte to float. Then you've ...

Re: Digital PLL acquisition problem

I have read your article : Efficient Multitone detection... It's a fully good article with lots of tips and tricks... Monday I'm going to test it in our application where we need to detect 6 tones from 1kHz to 75 kHz The difference with the DTMF and our application is that we can have the...