steve@tessi.uucp (Steve Willoughby) (10/31/90)
I'm playing around with building a circuit that will, among other
things, (try to) recognize DTMF tones played into it. An example
application of this would be to make your own voice-mail system (the
circuit would look for DTMF keypad keys pressed on the incoming line
and signal a CPU to do something, like play or record a message.)
The problem is that I can't seem to find any references to
DTMF-decoder chips or schematics of discrete-component circuits to do
this function. Any help would be appreciated.
Thanks in advance,
Steve Willoughby N7PFJ
steve@aardvark.pdx.com
(sun.com!nosun!tessi
!aardvark!steve) meier@uunet.uu.net (Rolf Meier) (11/02/90)
In article <14220@accuvax.nwu.edu> Steve Willoughby <aardvark! steve@tessi.uucp> writes: X-Telecom-Digest: Volume 10, Issue 780, Message 5 of 13 >I'm playing around with building a circuit that will, among other >things, (try to) recognize DTMF tones played into it. An example >application of this would be to make your own voice-mail system (the >circuit would look for DTMF keypad keys pressed on the incoming line >and signal a CPU to do something, like play or record a message.) Mitel Semiconductor has an integrated DTMF receiver chip, MT8870. This should do the trick. In North America, call 1-800-267-6244. In Portland, try Time Electronics, (503) 684-3780. Rolf Meier Mitel Corporation
segal@uunet.uu.net (Gary Segal) (11/05/90)
mitel!spock!meier@uunet.uu.net (Rolf Meier) writes: >In article <14220@accuvax.nwu.edu> Steve Willoughby writes: >>I'm playing around with building a circuit that will, among other >>things, (try to) recognize DTMF tones played into it. An example >>application of this would be to make your own voice-mail system (the >>circuit would look for DTMF keypad keys pressed on the incoming line >>and signal a CPU to do something, like play or record a message.) >Mitel Semiconductor has an integrated DTMF receiver chip, MT8870. >This should do the trick. Before this turns into a shouting match by all of the people that make DTMF decoders, please note that Mitel is not the only company that makes them. Of course, I'd like to see you use the Motorola chip (MC145436), but it sounds like your best bet is to go to your local Radio Shack and buy whatever manufacturer happens to be in the bubble pack. Gary Segal ...!uunet!motcid!segal +1-708-632-2354 Motorola INC., 1501 W. Shure Drive, Arlington Heights IL, 60004 The opinions expressed above are those of the author, and do not consititue the opinions of Motorola INC.
tad@ssc.UUCP (Tad Cook) (11/05/90)
In article <14220@accuvax.nwu.edu>, aardvark!steve@tessi.uucp (Steve Willoughby) writes: > The problem is that I can't seem to find any references to > DTMF-decoder chips or schematics of discrete-component circuits to do > this function. Any help would be appreciated. Check with Teltone. They sell touchtone receivers. You could also talk to SSI (Silicon Systems), although I don't remember their address. They are in southern California. There is an application circuit for the SSI chip on page 34-3 of the 1990 ARRL Handbook. Stay away from circuits in the older ham radio literature that use 567s and discrete components. Here is how to get in touch with Teltone: Teltone Corp. 10801 120th Ave. NE Kirkland, WA 98033 206-827-9626 Tad Cook Seattle, WA Packet: KT7H @ N7HFZ.WA.USA.NA Phone: 206/527-4089 MCI Mail: 3288544 Telex: 6503288544 MCI UW USENET:...uw-beaver!sumax!amc-gw!ssc!tad or, tad@ssc.UUCP
gauthier@ug.cs.dal.ca (Paul Gauthier) (11/05/90)
In article <14326@accuvax.nwu.edu> tad@ssc.UUCP (Tad Cook) writes: >In article <14220@accuvax.nwu.edu>, aardvark!steve@tessi.uucp (Steve >Willoughby) writes: >> The problem is that I can't seem to find any references to >> DTMF-decoder chips or schematics of discrete-component circuits to do >> this function. Any help would be appreciated. Check one of the recent issues of {Radio & Electronics} at your local library. One of their recent projects was a board for IBMs which allow detection of DTMF sounds and other pretty nifty control features of the phone line. Schematics, pinouts, traces, etc are all in the article. I'm not sure which month it was in. I also believe a source for a complete kit was listed in the article. PG gauther@ug.cs.dal.ca tyrant@ac.dal.ca tyrant@dalac.bitnet
art@wciu.edu (Art Nicolaysen) (11/06/90)
In article <14377@accuvax.nwu.edu> gauthier@ug.cs.dal.ca (Paul Gauthier) writes: >Check one of the recent issues of {Radio & Electronics} at your local >library. Also, try the April 1982 issue of BYTE, in the "Ciarcia's Circuit Cellar" column. A DTMF decoder project discusses alternate design schemes, includes schematics. BYTE Publications also issued a series of books that included the Circiut Cellar projects. Art Nicolaysen William Carey Int'l University (Global Mapping) art@wciu.edu Pasadena CA 91104
meier@uunet.uu.net (Rolf Meier) (11/06/90)
In article <14327@accuvax.nwu.edu> motcid!segal@uunet.uu.net (Gary Segal) writes: >Before this turns into a shouting match by all of the people that make >DTMF decoders, please note that Mitel is not the only company that >makes them. Of course, I'd like to see you use the Motorola chip >(MC145436), but it sounds like your best bet is to go to your local >Radio Shack and buy whatever manufacturer happens to be in the bubble >pack. I don't know about Radio Shack in the U.S., but in Canada they have the habit of selling components which are "seconds". I suggest that you go to a qualified distributor/representative if you want quality components, be it Mitel, Motorola, or whoever. Ever notice how little ESD protection there is in the Radio Shack packages? Rolf Meier Mitel Corporation
BRUCE@ccavax.camb.com (Barton F. Bruce) (11/06/90)
In article <14220@accuvax.nwu.edu>, aardvark!steve@tessi.uucp (Steve Willoughby) writes: > The problem is that I can't seem to find any references to > DTMF-decoder chips or schematics of discrete-component circuits to do > this function. Any help would be appreciated. Get the chip handbooks from several of the major chip houses. There are often seperate handbooks for telecom devices. There are plenty of TT chips made. If you are just tinkering, go to Radio Shack. They have TT decode chips, but are hardly where you need to go if you are going to make a product. BTW, just use a DTMF decode chip. DON'T try to do it yourself.
phil@ucbvax.berkeley.edu (Phil Weinberg SPS) (11/07/90)
In article <14220@accuvax.nwu.edu>, aardvark!steve@tessi.uucp (Steve Willoughby) is quoted as saying earlier: > The problem is that I can't seem to find any references to > DTMF-decoder chips or schematics of discrete-component circuits to do > this function. Any help would be appreciated. Motorola Semiconductor makes a DTMF decoder chip called the MC145436. It's available in a DIP package as a MC145436P ($3.09/each) or in a surface mount version MC145436DW (also $3.09 each). It should be available at your Motorola authorized distributor. You might want to get a copy of Motorola's Telecommunications Device Data Book (motorola P/N DL136/D) which has all kind of telecom goodies (or is that goodys?) that are available as standard off-the- shelf devices. No disclaimer. I work for Motorola Semiconductor and hope you buy bunches of our circuits!! << Usual Disclaimer >> Phil Weinberg @ Motorola Semiconductor, Sunnyvale, CA 94086-5395 UUCP: {hplabs, mot,} !mcdcup!phil Telephone: +1 408-991-7385
tad@ssc.UUCP (Tad Cook) (11/10/90)
In article <14411@accuvax.nwu.edu>, BRUCE@ccavax.camb.com (Barton F. Bruce) writes: > If you are just tinkering, go to Radio Shack. They have TT decode > chips, but are hardly where you need to go if you are going to make a > product. Radio Shack no longer carries the SSI DTMF receiver. But you can contact SSI directly at 714-731-7110. Or you can get Teltone's DTMF receiver from them at 206-827-9626. Tad Cook Seattle, WA Packet: KT7H @ N7HFZ.WA.USA.NA Phone: 206/527-4089 MCI Mail: 3288544 Telex: 6503288544 MCI UW USENET:...uw-beaver!sumax!amc-gw!ssc!tad or, tad@ssc.UUCP
murray@sun13.scri.fsu.edu (John Murray) (11/12/90)
In article <14411@accuvax.nwu.edu>, BRUCE@ccavax.camb.com (Barton F. Bruce) writes: > If you are just tinkering, go to Radio Shack. They have TT decode > chips, but are hardly where you need to go if you are going to make a > product. In article <14544@accuvax.nwu.edu> tad@ssc.UUCP (Tad Cook) writes: >Radio Shack no longer carries the SSI DTMF receiver. But you can >contact SSI directly at 714-731-7110. Or you can get Teltone's DTMF >receiver from them at 206-827-9626. Hmm ... check your local Radio Schlocks anyway! Just today I saw three or four1 of the DTMF decoder chips on the clearance racks in a local Schlock for, oh, 4.95 or so (the original price was a little above $10.00). Disclaimer: Any opinions above (or below) have nothing to do with reality. John R. Murray murray@vsjrm.scri.fsu.edu Supercomputer Research Inst.