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Dtmf 8870

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41 Threads found on edaboard.com: Dtmf 8870
Hi, I have written a C code using CodeVision AVR and Tiny2313 to detect dtmf tones using 8870 and turn on the relay if any of the valid code is found. Code is as followsm, #include #include #define EST PIND.1 #define STD PINA.1 #define Q4 PINA.0 #define Q3 PIND.2 #define Q2 PIND.3
Hi, I want to design 2 digit dtmf decoder using 8870 dtmf decoder. Means 00 to 99 should be displayed on two 7 segments. No use of microcontroller.. Using one 7 seg display is quite easy but how to do it with two 7 segment display. CAn anybody suggest some rough schematic.
I know that we can control the output connected to the 8051 ports through mobile by interfacing dtmf decoder 8870 with 8051 .....but can i get information of some inputs connected to the 8051 to my mobile by interfacing any other device with 8051??..... if yes ,please help me out by informing about that device.......?
HI FRIENDS 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
Hello sir what is the basic use of CM 8870 i.c. , what we call it ? Seems it is related to sound work , please explain in very short Its dtmf decoder (receiver), decodes dual tones and . IC id is 8870 and CM is manufacturer, also there is other manufacturers of this IC with other prefix to 887
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
Circuit is bad, what you plan with thise diodes on output ? See circuit examples : www.radiolocma
i used 8870 i connect the hand free to 8870 i press key it not generate any out put i check crystal frequency it is 2.9MHz so i replace the crystal but problem still remain then i replace both capacitor of 33pf & crystal but problem sill remain i change ic 8870 with a ic 8870 which work in other circuit but the (...)
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.
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 ke
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 Changing Mobile...... Please Reply if Any One have Exp
I constructed the circuit with cm8870 (dtmf decoder) as shown in it's data is working wen I connect it's input to my PC and generate dtmf. but when I use to connect my cellpho
I want to interface 8870 dtmf ic with 8051 what is the program for ....this when we press 1, 2... like this thankyou Can be more specific ? You need to decode dtmf using 8051 and show number on 7-seg LED or LCD ? Interfacing 8870 dtmf decoder with 8051
I want to interface 8870 dtmf IC to uC 8051..... problem is output of 8870 is binary and how to program 8051 for a binary input. as I want, when i press 1 2 3 from my cell phone the relay is latched,and again when I press 3 2 1 that get back to its original position.. Please help for this problem...
I will be designing using MT8870 dtmf detector and using the HT9200 dtmf Generator both use AT89C51 ..... I have made it alone detector and generator run ,, the results ok .... I want to combine both, but the code that I made did not work .. please help me in troubleshooting the code just use asm ;**************************************
Hello everybody I want to design and make a ID caller with 8870 and 8951 and LCD . please help me to makes code ASM for conversi dtmf to LCD
i m making project on dtmf decoder and i am unable to get output through my mt8870 ic .i have tried different gain by changiing resistor values between ppin 2 and pin3.but still no breakthrough in the circuit. please help me out.
The outputs are all low if 'E' is high so you must pull it low if you want anything on the output pins. 'EL' enables the data into the latches when it is high and holds it there when it goes low. You can connect it to the 8870 'Std' output so you get one of 16 outputs which go active (high) when a dtmf tone is received and stay active until a diffe
Just check this old reply for dtmf decoder query Regards Chanchal
They are nothing more than tone decoders. If the tones are present in the on-hook state and you have suitable coupling to the line, they will work. dtmf decoders normally have on-board bandpass filters to ensure only the high and low tone groups are monitored, other tones on the line will be ignored. Brian.