31 Threads found on edaboard.com: Dtmf From Mobile
dtmf is like a voice. If you do not use a mic to detect this sounds you do not need a dtmf receiver , if you want to communicate with cell phone by data cable or IRDA , it is just a digital communication. dtmf has nothnig to do with it.
Microcontrollers :: 17.09.2004 10:34 :: Free_Will :: Replies: 11 :: Views: 7984
Are you using this :- MT8870 datasheet pdf datenblatt - Mitel Networks Corporation - ISO2-CMOS Integrated dtmf Receiver ::: ALLDATASHEET :::
it says the input is on pin.
Hobby Circuits and Small Projects Problems :: 30.08.2011 15:32 :: chuckey :: Replies: 6 :: Views: 2086
dtmf can be detected if the call is from a telophone by sim900, but how can i detect dtmf from a gsm , or in othor words how can i send dtmf tone from my mobile...
i am confused as when i call a callcenter they automaticaly detect dtmf tone if i send it (...)
Microcontrollers :: 18.10.2011 06:45 :: sherazi :: Replies: 0 :: Views: 730
what is your question?
you need multiple interfaces, including the dtmf detector is drived from speaker output your mobile phone
Microcontrollers :: 13.02.2012 06:10 :: Li_ereunpisan :: Replies: 1 :: Views: 442
i use sim900 and firmware
i also use mic for ivrs
when there is no voice transfer form modem to mobile.....dtmf are working
but when there is a voice transfer from modem to mobile.....dtmf are not working properly ,some time randomly (...)
Digital communication :: 22.10.2012 09:38 :: nngohel :: Replies: 4 :: Views: 2841
I have used the Sony Ericson GM29 cellular modem
You can send & receive SMS messages via RS232 interface
This modem cost around $120 and work for GSM network
You can also send Audio command via this modem for instance dtmf signal after esablishing a connection.
It's a bit simple idea from using SMS messages
You can search th
Microcontrollers :: 15.11.2003 10:40 :: bobcat1 :: Replies: 5 :: Views: 1817
the project is "wireless security door lock"-----> it means that:
1) i have a door like one of my home this door will not open unless i enter
thecorrect password saved on the EEPROM of the ?controller.
2) i am aiming to enter this password from the keypad of my mobile(GSM)
,so there is two solutions:
1st >> connecti
Network :: 24.07.2006 23:17 :: veiledcavalier :: Replies: 5 :: Views: 1585
you can use a dtmf to bcd decoder.you ll get a bcd output which you can interface with a ?c and do whatever you want.once i used this to interface with a mobile phone to control 4 switches of course you can control more .heres a schematic which you can connect to landline and control 4 switches.you need to dial the landline and press 0(im not sure
Microcontrollers :: 18.03.2007 11:09 :: nipun :: Replies: 2 :: Views: 1243
hi 2 all
im currently working on voice interactive system ..........
im using cell phne at reciving end. can any body tell me how do i detect which key pressed from the dialing end ?
do i use AT cmmands or dtmf tone decoder ic ???
Microcontrollers :: 06.09.2007 14:48 :: drbizzarow :: Replies: 2 :: Views: 715
Hope you are doing well.
I have been working with the dtmf decoder MT8870 for few months but i could not get success. I have used few circuits mentioned in the datasheet. But i am facing problem *, 0, # , 7, 8 ,9 buttons are working but sometime works the 1, 2, 3, 4, 5, 6.
Why is that???
I have connected to MT8870 Pin 2,
Microcontrollers :: 15.02.2009 07:56 :: sakaz :: Replies: 5 :: Views: 11259
it must work
i have made it sevrel times.
u can do use, fm transmitter/reciever for dtmf transmition.
best dtmf generator ic is ht9200.
this is 8 pin serial generator.
u must use MCU to use it.
Microcontrollers :: 28.04.2009 08:36 :: Noman Yousaf :: Replies: 10 :: Views: 9892
I am interfacing a mobile phone with a micro controller using a dtmf decoder (HT9170) and the signals from the head set cable. I need a provision to detect when the call has ended. Most circuits in the net are for phone lines
Thanks for the help
Microcontrollers :: 16.12.2009 08:35 :: vysakhpillai :: Replies: 0 :: Views: 1488
try to change gain of preamplifier resistors of 100K because gain in your circuit=1 so the voltage of dtmf signal must be bigger enough to tigger the MT
for example try 1M by 10K
Digital Signal Processing :: 08.06.2010 11:17 :: jacob_abraham :: Replies: 5 :: Views: 1515
I am doing a project on GSM.. In that i want to detect the key pressed at the other side on active call.... I am trying with a dtmf decoder circuit at speaker output but it is not working...Plz if any one has any other idea or solution plz reply...........
Microcontrollers :: 11.11.2010 01:05 :: Manu.electronics :: Replies: 4 :: Views: 4451
Hello everyone! My name is Franck. I am final year student. I am doing my project now but it is not working. My problem is with the dtmf decoder circuit. I am using the MT8870 dtmf decoder IC, the MT8870 dtmf decoder circuit is given in its datasheet and it is not giving me any ouput. I am pretty sure my problem lies at the input. The input (...)
Electronic Elementary Questions :: 27.01.2011 10:46 :: Franck1991 :: Replies: 0 :: Views: 2040
i dont knw if i am dnd andything wrong but i am not gting the led lit
is there anyway yo check if the chip is working ?mayb tats wat tat has gone wrong
There are lot of fake ic's found in the market, especially dtmf decoder. Try a different chip from different dealer/shop.
Analog Circuit Design :: 19.05.2011 08:55 :: nandhu015 :: Replies: 19 :: Views: 2462
i made aproject using a gsm mobile dtmf based home light that i need two things.
1. pasword system
2. when we do press any key then from my device side it inform about it accepted operation and welcome message and other message also.
so please guid me about this process.
Analog IC Design and Layout :: 26.08.2011 13:17 :: deepakgupta.rf :: Replies: 0 :: Views: 638
My alarm panel will call my mobile phone when it is activated. However, to acknowledge that I have received the notice, and so stop the alarm panel from resending the alert, I need to reply with a 1400 Hz hand shake kiss off signal tone.
If I press the button on my phone, this will generate a dtmf 1477 Hz and 697 Hz tone. Will this be close
Hobby Circuits and Small Projects Problems :: 02.02.2012 16:04 :: JohnJohn20 :: Replies: 4 :: Views: 1722
You can set autoanswer option in phone to answer just on particular phone numbers (yours) this will prevent someone else to press some digits and activate/deactivate some relays.
Use handsfree headspeakers for input to your circuit. Input section of your circuit should be modified to accept lower voltage signal from handsfree headspeaker.
Digital communication :: 20.03.2012 12:36 :: tpetar :: Replies: 2 :: Views: 446
I have attached the dtmf decoder circuit using MT8870 IC. I that circuit, at the input section two zener diodes are used face to face..
I want to know why it is used...???
i am using a mobile phone instead of telephone.... its working fine... but can i remove those zener diodes...???
Thanks in adva
Digital communication :: 01.05.2012 04:04 :: nithin kamath :: Replies: 2 :: Views: 823
as a part of project i had connected mobile to dtmf Decoder Works Well(gives Output for all switch pressed ) But when I Make A call from Another mobile to the mobile that is connected to dtmf DECODER It Only gives output for pin Number 3 6 9 What Shoud Be the Reason?
I have Also Tried after (...)
Analog Circuit Design :: 11.10.2012 12:03 :: gajjar.nirav :: Replies: 0 :: Views: 440
i was working on dtmf decoder(MT 8870) lately and during that time i found that it was giving proper o/p on galaxy fit but not able to decode and give o/p on galaxy Y.Just try to plug in the device which gives you undesirable output and make a call from which you are getting correct output.
P.S when you jack in aux wire make sure your phones media
Hobby Circuits and Small Projects Problems :: 30.04.2013 06:20 :: gaurangpatel :: Replies: 11 :: Views: 635
your cellphone should able to produnye dtmf signal caose otherwise it wont't work.
and signal from cellphone should connect to input of MT8870
Electronic Elementary Questions :: 04.01.2006 04:30 :: e_eja :: Replies: 3 :: Views: 1044
One suggestion :
1) Do you have an oscilloscope and can you check if you ARE getting the dtmf tones on those pins ? I had an pre-assembled modem with a RJ jack for a handset.I used the handset jack to take the dtmf tone. Hence I did not have to go deeper into the modem.A problem I still have is that sometimes the dtmf tones are (...)
Electronic Elementary Questions :: 08.05.2009 15:47 :: phaedrus :: Replies: 2 :: Views: 3185
post the already existing one so that suggestion of upgrade can be made. any way you can use dtmf chip to decode tones of keys pressed from transmitter phone from any where in d world checking if it's correct sequence then operates a relay in your case open/ close door.
Digital communication :: 28.06.2009 04:17 :: codewiz :: Replies: 12 :: Views: 6310
I have a project where i need to transmit some command bits using wireless mode of communication. Considering its usage as a mobile surveillance unit, range should not be around 200 m or so.
I need advice what options do i have?
here's what i was planning.
Using a pair of GSM cells one at control end and other at mobile unit end.I plan to c
Hobby Circuits and Small Projects Problems :: 05.09.2009 03:34 :: INS-ANI :: Replies: 3 :: Views: 1402
Hi concerning task 1: i prefer PIC18F4550, also you will find on microchip website "Microchip USB framework", these are ready made USB firmwares customized for microchip microcontrollers, but you will need MPLAB 8.2 or higher and C18 compiler, one of these projects you can make PIC mcu act as a host which mean you can connect other USB peripherals
Microcontrollers :: 16.09.2009 08:37 :: elrayes :: Replies: 5 :: Views: 2675
how i can send 10 tone per second using cellphone the min time i get is 10 tone /5s which is to long , do you know how to do that or a mobile send fast dtmf ??
please help its for my project .........h.e.l.p.p.l.e.a.s.e.....
Microcontrollers :: 12.02.2011 07:47 :: khaldun904 :: Replies: 5 :: Views: 550
1st decide weather to connect with ur ear phones...if so then just find out the basics of dtmf...n later u can interface it with Microcontroler such as 8051 or so... .
then learn the basics for micro cntroller so that u can easyly build up ur own robo...
Microcontrollers :: 20.04.2012 11:08 :: seshuonlyme :: Replies: 2 :: Views: 275
At command set is for sending messages or receiving messages and dialing a phone. For that you need a Sim card and network connection. But in your case you can make use of dtmf(dial tone multi frequency).
B clear whether you want to press keys and do the project go for dtmf
if you want to send message then go for GSM module with AT Command Set.
Professional Hardware and Electronics Design :: 01.04.2012 07:28 :: aameer :: Replies: 24 :: Views: 1508
dtmf decoder MT8870.
Microcontrollers :: 23.08.2013 11:37 :: oufuqiang :: Replies: 3 :: Views: 282