Actly we are doing a project DTMF detection by using this kit. We hav taken
fft of the dtmf tone and the determined the position of all the row and
column frequencies and also their magnitude. The row frequency and column
frequency having largest magnitude will decide which key has been pressed.
But after writing the program when we are running the program taking input
from 'mic in' we are getting a continuous noise in our headphone due
which
it is giving random output. Can u please help to remove that continuous
noise?
Doubt regarding C6416
Started by ●April 4, 2013
Reply by ●April 4, 20132013-04-04
Do you get the noise when you don't do the FFT?
________________________________
From: Swayamsampanna Padhi
To: c...
Sent: Thursday, April 4, 2013 1:16 AM
Subject: [c6x] Doubt regarding C6416
Actly we are doing a project DTMF detection by using this kit. We hav taken fft of the dtmf tone and the determined the position of all the row and column frequencies and also their magnitude. The row frequency and column frequency having largest magnitude will decide which key has been pressed. But after writing the program when we are running the program taking input from 'mic in' we are getting a continuous noise in our headphone due which it is giving random output. Can u please help to remove that continuous noise?
________________________________
From: Swayamsampanna Padhi
To: c...
Sent: Thursday, April 4, 2013 1:16 AM
Subject: [c6x] Doubt regarding C6416
Actly we are doing a project DTMF detection by using this kit. We hav taken fft of the dtmf tone and the determined the position of all the row and column frequencies and also their magnitude. The row frequency and column frequency having largest magnitude will decide which key has been pressed. But after writing the program when we are running the program taking input from 'mic in' we are getting a continuous noise in our headphone due which it is giving random output. Can u please help to remove that continuous noise?
Reply by ●April 6, 20132013-04-06
We are getting the noise while taking the input. Whenever we press any key
in the mobile phone that tone is heard along with noise which is
continuously coming without giving the input also
On Fri, Apr 5, 2013 at 10:43 AM, Swayamsampanna Padhi wrote:
> We are getting the noise while taking the input. Whenever we press any key
> in the mobile phone that tone is heard along with noise which is
> continuously coming without giving the input also.
>
in the mobile phone that tone is heard along with noise which is
continuously coming without giving the input also
On Fri, Apr 5, 2013 at 10:43 AM, Swayamsampanna Padhi wrote:
> We are getting the noise while taking the input. Whenever we press any key
> in the mobile phone that tone is heard along with noise which is
> continuously coming without giving the input also.
>
Reply by ●April 6, 20132013-04-06
We are getting the noise while taking the input. Whenever we press any key
in the mobile phone that tone is heard along with noise which is
continuously coming without giving the input also.
in the mobile phone that tone is heard along with noise which is
continuously coming without giving the input also.
Reply by ●April 6, 20132013-04-06
Padhi,
Exactly where are you attaching the headphone to hear that noise?
Have you tried disconnecting the keypad? is the noise still there?
Have you tried attaching an oscilloscope to your power supply outputs? How
clean is that signal?
Have you tried turning off the A/D? Is the noise still there?
have you tried attaching a oscilloscope to the outputs of the A/D? Is the noise
still there?
What is the frequency of the noise? Does it have any relationship to the
sampling rate of the A/D?
R. Williams
---------- Original Message -----------
From: Swayamsampanna Padhi
To: c...
Sent: Fri, 5 Apr 2013 10:43:56 +0530
Subject: [c6x] Re: Doubt regarding C6416
> We are getting the noise while taking the input. Whenever we press any
> key in the mobile phone that tone is heard along with noise which is
> continuously coming without giving the input also.
------- End of Original Message -------
_____________________________________
Exactly where are you attaching the headphone to hear that noise?
Have you tried disconnecting the keypad? is the noise still there?
Have you tried attaching an oscilloscope to your power supply outputs? How
clean is that signal?
Have you tried turning off the A/D? Is the noise still there?
have you tried attaching a oscilloscope to the outputs of the A/D? Is the noise
still there?
What is the frequency of the noise? Does it have any relationship to the
sampling rate of the A/D?
R. Williams
---------- Original Message -----------
From: Swayamsampanna Padhi
To: c...
Sent: Fri, 5 Apr 2013 10:43:56 +0530
Subject: [c6x] Re: Doubt regarding C6416
> We are getting the noise while taking the input. Whenever we press any
> key in the mobile phone that tone is heard along with noise which is
> continuously coming without giving the input also.
------- End of Original Message -------
_____________________________________
