14 Threads found on edaboard.com: Dtmf From Mobile
NOW AM INTERFACE 8870 WITH NOKIA 2310 CELL PHONE i check dtmf 880 q1,q2,q3,q4, outputs are working pressing all keys on only that mobile only and not working remote operation another mobile why.............???
am using c1=0.1uf, r1=10k, pin 2
r2=10k , pin 3
Microcontrollers :: 02-13-2014 01:43 :: BHARATHSRI :: Replies: 1 :: Views: 325
dtmf decoder MT8870.
Microcontrollers :: 08-23-2013 11:37 :: oufuqiang :: Replies: 3 :: Views: 388
I am using dtmf 8870 decoder for my project of cell phone based voting machine.The decoder is giving correct output whenever any input is being given by the phone(say, M1) connected to the circuit..but whenever i am giving any input from another mobile (say M2) through M1 it is not responding to the inputs other than 3,6,9,#..
what is (...)
Hobby Circuits and Small Projects Problems :: 04-15-2013 02:59 :: toshalimitra :: Replies: 11 :: Views: 778
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 :: 10-22-2012 09:38 :: nngohel :: Replies: 4 :: Views: 3965
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 :: 10-11-2012 12:03 :: gajjar.nirav :: Replies: 0 :: Views: 559
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 :: 05-01-2012 04:04 :: nithin kamath :: Replies: 2 :: Views: 942
what is your question?
you need multiple interfaces, including the dtmf detector is drived from speaker output your mobile phone
Microcontrollers :: 02-13-2012 06:10 :: Li_ereunpisan :: Replies: 1 :: Views: 504
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 :: 10-18-2011 06:45 :: sherazi :: Replies: 0 :: Views: 904
I want to decode the dtmf tones sent from mobile's microphone but i have stuck in this. I am not getting output. I think there may be some problem in earphones' output .. Tell me how to connect earphone to dtmf decoder's IC. I am using MT8870.
Hobby Circuits and Small Projects Problems :: 08-30-2011 08:40 :: Pulkit Varshney :: Replies: 6 :: Views: 2349
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 :: 08-26-2011 13:17 :: deepakgupta.rf :: Replies: 0 :: Views: 746
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 :: 12-16-2009 08:35 :: vysakhpillai :: Replies: 0 :: Views: 1599
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 :: 09-06-2007 14:48 :: drbizzarow :: Replies: 2 :: Views: 827
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 :: 03-18-2007 11:09 :: nipun :: Replies: 2 :: Views: 1345
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 :: 09-17-2004 10:34 :: Free_Will :: Replies: 11 :: Views: 8313