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...

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

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...

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

Hello, I am implementing DTMF detection using Goertzel Algorithm.I have two questions 1.Since the duration of DTMF signal present is 40 msec...

Hello, I am implementing DTMF detection using Goertzel Algorithm.I have two questions 1.Since the duration of DTMF signal present is 40 msec and Goertzel takes 25msec should I detect the energy of incoming signal (at 3Khz) and then start Goertzel.(If I start my Goertzel after 20msec of actual signal I need another 5 msec more DTMF signal presence.But valid DTMF is available only for 20 msec....

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...

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

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...

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 analisys). I take a look at JTAPI but i don't have any telephone in this context, i just have to analyze ...

Can any body help me in writing code of following problem in...

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 Oscillators and write it in a wav file

Hi, I'm currently using the Goertzel algorithm to do DTMF detection. Currently, I get the magnitude for each DTMF frequency, save the...

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 seems kludgy. I do it this way because I'm having a hard time determining an appropriate threshold val...

Hi. I?m a newbie in this but I need to acomplish a job with this stuff. I?m capturing sound through the sound blaster and then need to detect if...

Hi. I?m a newbie in this but I need to acomplish a job with this stuff. I?m capturing sound through the sound blaster and then need to detect if there were some DTMF. For this I?m using Goertzel. What I can?t understand is about buffering and samples, I mean: Do I have to run the goertzel for N=106 on each sample and sum all the results and then try to detect if there were DTMF or this is processi...

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...

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 me on this. thanks.

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

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

Hello all, As a term project I would like to implement a simple DTMF decoder on a Blackfin BF533 EZ-KIT development board. I have the...

Hello all, As a term project I would like to implement a simple DTMF decoder on a Blackfin BF533 EZ-KIT development board. I have the necessary matlab files to generate the tones and I have created 8 FIR bandpass filters, one for each DTMF frequency +/- 20Hz. I made these in Matlab using fdatool and output to a 16 bit signed integer. I took Analog Device's Talkthrough example program and...

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...

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

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....

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

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...

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

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...

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 have found people using the Goertzel Algorithm, along with other methods. I need to find the most s...

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.

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.

I am facing some issue with my echo cancellation module. I am having a correlator and an adaptive filter modules. My correlator will detect...

I am facing some issue with my echo cancellation module. I am having a correlator and an adaptive filter modules. My correlator will detect presence of echo in the DTMF tones and will activate the adaptive filter. The adaptive filter will remove the echo present in the DTMF tones. Activation of adaptive filter is done only if the correlation is above a certain threshold. My issue is t...

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

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...

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 I have problem with the arrays [ dinamically generated]and with memory addresses. Does anybody h...

OK, determining the two frequencies of a single DTMF pulse where the starting location of the pulse (mark) is known, under ideal conditions, using...

OK, determining the two frequencies of a single DTMF pulse where the starting location of the pulse (mark) is known, under ideal conditions, using Goertzel , is like taking candy from a baby. After recording a sequence of marks and spaces I can once again determine their associated frequencies. The way I do this is to visually look at the recorded waveform. From there I can see the starting lo...