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96 Threads found on Dtmf Control
I am about to do a proj regarding dtmf control of home appliance using mobile phone..i have many where to fix the appliance..and which key turns on/off which appliance....can any1 please help me!!!!
Hi all, ı cant enabled the dtmf decoder in sim900D what's the AT commands pls hlp me :(
:) Sirs Its a phone interface to use with any microcontroller/microprocessor. Features - Detect Ring - Hook on/off control - Read dtmf signal - (use to control any application) Have Fun Jean Fernandes Coneel Smart Solutions
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.
you will have to connect the dtmf decoder to the PIC pins. Then you can input the port status. This is not very difficult. Also you can look at google, their exist plenty designs with dtmf decoder chips, maybe also with yours.
Hi , i am having problem working with UM91214b IC (dtmf generator IC ). Can you suggest some other commonly available dtmf IC ,and its reciever. You can also suggest me some circuit that you've tested with UM91214b. I am using it for remote control application. Thanks !!
There is a well designed and simple to build dtmf intercom circuit using telephone handsets shown at: The details and parts list for the dtmf portion are at:
Dear Friends Currently I am working on a Intruder Alarm system project with auto-dialer facility. In our system we dial the remote user during security break-up, also we are giving facility to control the system using dtmf keys from the remote side. Now we are facing some problems: (1) Initially we designed the hardware, then we wrote the s
Use MT88L85 for dtmf coder/decoder and a simple FM transceiver to make wireless
hi all, i've an application wherein i have to control remote home appliances using a dtmf remote telephone switch.Once a telephone connection is in place,a transmitted tone can be used in order to trigger a desired action.This technique,well known from its use in remotely accessing answering machines or conversing with service providers,here al
i want to make a teleremote. in which i can control one or more relays by using dtmf and telephone line. the problem is, how can i off hook the line by using a relay and/or any circuit? pleas tell me. i don't want to use telephone set thanks in adv
Hi Can anybody tell me how to use the dtmf tranceiver IC (MT8880) over a FM Transmitter/Receiver modules i.e inputs outputs and control, data transmission/receiving using parallel port and C Language. Please help if anybody have used this IC. Thanks.
hi guys. im trying to do a project. the last project i tried to do failed and didnt work due to my lack of understanding the 8051 and missing a lot of things. my last project was something like this. i wanted to communicate between two cars, which would communicate with each other and the lcd display in each car would show the distance be
Hi, I'm looking for a schematic for interfacing telephone line to a dtmf decoder (HT9172 Holtek), in order to build a remote control activated by phone. Tkx.
you can use audio dtmf method dial the phone then send dtmf tones {change the xtal that runs the dtmf chip to change its tones arrays} this way its modified so as not to trigger the standard telephone dial circuit ctcss seems a good cheep method with just a micro c both methods amount to the same thing
hi, i am using MT8880 which is a dtmf transceiver..after initialisation of control reg i am giving the input of 7 i want to know, how to check that wheather this IC is txansmitting dtmf signal or not thank u in advance just connect the output to a working telephone line. You can hear the tone simple Na
hi, i am using MT8880 which is a dtmf transceiver..after initialisation of control reg i am giving the input of 7 i want to know, how to check that wheather this IC is txansmitting dtmf signal or not thank u in advance
you can use a dtmf to bcd 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 need to dial the landline (...)
Please download this file
hai i had made a remote control using dtmf . but how to make o/p of 8870 to 0000 on power up . it is giving jung values on power up
Zarlink ( ) has both dtmf transmitters , receivers and transceivers
Hi from Turkey. I'm preparing for a competition which is about "Technologies Connecting to Life". In this competition, our main theme is making life easier for handicapped people (mental, physical etc.). This is a student competition so we are not supposed to do complex or expensive projects. I have decided to make an automatic door opener (I am
this one out, Instead of audio, you send your desired CODE and it must be of varying voltages. OK, suppose you take a TONE and transmit it, but the thing is that how will you decode at the other end. If you use the TONES of the telephone, then it can be decoded by th
Ofcourse you can do it if you have 2 cellphones. Make a call from one phone to the other and you must have some auto answer facility on the latter. Now when you press any key on the first phone you can hear a dtmf signal (corresponding to the key you pressed) on the second phone. You may tap the earphone/headset output of the second phone and decod
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 want to use the same dtmf tone (...)
hie I m Tejas doing my final year and m planning to take up dtmf controlled circuit application for eg. a wireless robot or a door lock etc. First of all i m newbie and dont have exact knowledge on dis. I want to know dat will dis circuit require using two cell phones one used as a remote and the other one on the robot or will a single mobile pho
hi, i have a project that about dtmf based stepper motor control via 16F877. when i pressed 4, the stepper motor turn anticlockwise. 6; turn the clockwise and 5 is stop the motor. how can i do this? anybody help me?
Is there any way that I won't use microcontroller in doing this project? Yes, there is. You can use a dtmf encoder at the transmitter side and, a dtmf decoder at the receiver side. Now, you have not only the 9 freqiencies you need but also 6 extra frequencies for future improvements. Take a look at the below link: wo
here is a data to dtmf tones dialer unit {not a decoder !!!} allows for several timing modes and full tones adjustment to reuse for other systems also can be reused as a submodel if you want to add other control logic and decoders as a unit submodel etc this unit provides squarewaves you can offset this in the usual way using a resistor an
I would like to make a 10 channel RF remote control to control the motion of my robotic car with a robotic arm that can perform some tasks. I'm going to use the IC UM91412B to generate dtmf, as what is posted at My problem is that I would like to make it operate
hello friends, i had designed 'dtmf based device control' and a sample project is here at , the problem is some of the tone are not recoginised by the dtmf decoder and it differs for each cellphone, what can be the problem and solution for the same. regards kj
My project (dtmf Teleremote control) spinning around a lot of strange problems. Every now and then it occurs and after some thought if cannot figure out, I go for Forum Thread posting. I optimize no one get bitterer by checking indistinguishable subject. But I anticipate this would be an open place to clear any doubts (basic to advanced) of a com
Lets imagine some situation. We are AT the Holiday. Sailing in transatlantic ship. Suddenly we realized that we have left iron plugged to power grid. No one is home, so only one solution is to call to your neighbors. Ok, but what if
Hi forum, I am building this dtmf decoder circuit. Although Instead of using a landline I wanted to use a cell phone as the receiver--(you can't run a wireless robot with a landline phone attached to it) all i need is for someone to verify that this circuit will function just the same with a cell phone, because I don't want to start buildin
i cant use dtmf because gsm module have not support dtmf. Is there any software solution for dtmf? There is no need for gsm module to support dtmf. You can use speaker/headphone output jack for detecting dtmf
check this, Home automation using phone (dtmf touch-tone)
hi everyone, i m interested in 'device control using dtmf' can anyone suggest me about this.any suggestion are heartly welcome.
hello sir, please help us... how to connect dtmf decoder and mobile phone & microcontroller
Hi i am a student working on a dtmf remote control device. I am using CM8870 decoder and am using a TP5089 to generate my dtmf. i am attaching the original schematic that i have found on web, but different dtmf generator chip that i am using. The transmitter side of the first schematic is being prototyped right now. So i (...)
hi, i am a student who are doing the final year project . i have done a simple light control system which remotely control via telephone. Everything function well when i do it at home , but when i want to use the telephone in the laboratory, my hardware is not function, ring detect is ok but dtmf signal cannot send to my hardware. After (...)
So,guys,i can use dtmf IC(generator and decoder) to send the tones and decode it and amplify the output to switch the circuits at the receiving ends..right? But my concern is: My RF audio transmitter has a slight noise....when i transmit the dtmf tones,will the decoder pick up the tones correctly????? And are dtmf IC's are still ava
You need an analog modulation method to transmit dtmf, e.g. AM or FM. Digital RF modules can't. It would be easy to transmit the tiny information content of dtmf signals in digital form, e.g. using a popular remote control encoder.
I am making a application in which I have to control the my robot using mobile phone. For that I am using a SIM300 GSM modem and standard MT8870 decoding circuit(Mentioned in the datasheet).Initially everything was working fine but after some time the speaker does not giving any output.I have tried connecting it with earphone but no response. I hav
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
Friends, Anyone knows on how to control relay using dtmf (MT8870) and AT89S52 ? How can I make the circuit answer the call automatically and accept command from dtmf ? The idea is, if there's a call, the circuit will auto pickup after 3 beep and ready for a command from a remote phone, for example, numeric "1" for turning on "relay 1" (...)
Dear Friends I am doing cell phone based device controller LINK- This one every thing working but my problem dtmf side only "MT8870" not decoding what is my problem I didn't under stand Please tell me :x
Hello edaboard recently I have been working on a remote automating system , building a circuit to recieve a dtmf signal from the telephone line and then do its job but I am facing some problems . CM8870 is the circuit I used , would be the magnetic iso
Hi Friends, i am doing voice call based device control using GSM & dtmf. i connect the speaker input line into dtmf input , my headset is response the call and dtmf tone but MT8870 not responding why????????????? (MT887 is dtmf decoder) Thanks in Advance.
Please I urgently need a working circuit and source code for a dtmf(eg.8870) and AT89S52 to control 4 relays(ON and OFF as desired) connected on Port2 of the AT89S52. The dtmf should be fed to port3 of the AT89S52. The Relays should be turned ON by the pressing of keys 1,2,3 and 4 respectively but can be Turned OFF by keys 5,6,7 and 8. In (...)