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1000 Threads found on edaboard.com: Dtmf Control
you are welcome..thats why we are here for...all we do in this site is help others by sharing our knowledge.. here now there is no security.. any one who wisheshes to call can conrtol your circuit.. so it is better you connect the output of dtmf decoder to micro controller and then connect the microcontroller to the next stage... i do not (...)
Hi all, ı cant enabled the dtmf decoder in sim900D what's the AT commands pls hlp me :(
Use MT88L85 for dtmf coder/decoder and a simple FM transceiver to make wireless
Zarlink ( ) has both dtmf transmitters , receivers and transceivers
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?
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
hi everyone, i m interested in 'device control using dtmf' can anyone suggest me about this.any suggestion are heartly welcome.
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" (...)
:) 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@engineer.com 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.
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
See this link, might be a useful....although they are not using dtmf Good luck
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.
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 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 (...)
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
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,
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. bye.
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
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
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
check this, Home automation using phone (dtmf touch-tone)
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.
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 (...)
I'm using MT8880 to generate dtmf tones only. My question is how should I terminate the IN+, IN-, GS, Vref, Est, St pins which I won't be utilizing. Thank you
What are codes for dtmf to operate the AT89C52... Can Anyone Help me....
Its possible. Almost every GSM phone can generate dtmf codes. But why to use dtmf codes, you need to establish connection, you can use SMS control.
Dear all, I'm working on a circuit to control the water pump based on dtmf code and cellphone. But the dtmf section is not working properly. While sending the dtmf code, pin # 11 to 14 is on high and no change in state and pin # 16 is at low state. This is the case for all dtmf codes which we are (...)
Hi, I need a complete project that will make use of a gsm to control 6 loads through dtmf. I will appreciate if the microcontroller is either AT89S52 or any PIC. Please include both the circuit diagram and the code thanks.
Hi, For a school project I need to design a signal generator which generates digital touch-tone-signals (dtmf) with duration of 60-70 ms that can be used in dtmf-telephony. the signals later will be fed to the on-board existing Digital-to-Analog converter and then to the exisiting on-board AC97 audio codec. I have spent long hours on researching