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31 Threads found on 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.
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.
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 (...)
what is your question? you need multiple interfaces, including the dtmf detector is drived from speaker output your mobile phone
Hi i use sim900 and firmware 1137b08sim900m64_st_dtmf_jd_mms 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 (...)
Hi 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
ok, 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
you can use a dtmf decoder to sence the telephone signals
ASA 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 ??? thx.
Dear forum, 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,
I am doing a project in which I have to control 3 servo motors and 2 DC motors on a mobile platform. It needs to be controlled in two modes. One is using a mobile phone on the robot which receives commands through dtmf tones from another mobile phone. The second one is from a computer. I (...)
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
well. 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
Hi................... 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...........
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 (...)
Hi guys, I have been trying to generate a dtmf decoder over the mobile phone.I am not interested in Landline because my motive is to generate a circuit for home automation and mobile i need to have a system to decode the dtmf generated by the mobile phone recieving end.:?: I am attaching the (...)
hello everyone 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.
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
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. You
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...??? 73455 Thanks in adva
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 (...)
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
i soldered a circuit for dtmf to bcd convertor using works fine with landline telephone.i want to use it with a isnt working with cellphone.i cut the wire to speaker of handsfree of a mobile and connected to the input of ic.still its not working.i intend to use it as a remote control by calling the mobile with another mobile
Hi Sakaz, 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 (...)
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.
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
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
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..... thanks
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...
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.
dtmf decoder MT8870.