UHF DTMF Radio?

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mikebaier
 
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UHF DTMF Radio?

Post by mikebaier »

my ultimate goal is to create a device that will take DTMF codes from a 2 way hand held radio to ultimately be able to control relays.

I have everything figured out with the exception of what breakout I can use to receive the actual radio signals, i'm looking for something in the 433 - 490 mhz range, I can reprogram a channel on my 2 way radios to match etc. Ultimately it would be ideal to be able to program the breakout board to match my existing frequencies etc.

any thoughts on this ? are there any adafruit UHF receivers that will allow this?

would this product ultimately give me what i'm looking for, plus the arduino interface for linking up to the relays?

https://www.adafruit.com/product/3177




thanks for any direction on this.

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adafruit_support_mike
 
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Re: UHF DTMF Radio?

Post by adafruit_support_mike »

The radio chip in the RFM96 module can be programmed for several different kinds of encoding, but we don't have any experience working with them that way. You'll need to look through the datasheets (linked from the Downloads page in the tutorial) and the low-level code in the RadioHead library.

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prairietech
 
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Re: UHF DTMF Radio?

Post by prairietech »

I don't think the Feather is what you want for a receiver. DTMF is an analog audio signal and not digital data like the Feather is designed to decode.
You need another radio similar to the one your sending the dtmf signals from. In the last few years, there has been a huge influx of cheap imported UHF coming into the USA. Many are around $30.00 or less. Ebay is full of them.
Simply connect your dtmf decoder to the earphone jack of such a radio and you should good to go. Be careful not to have the audio output level too high on the receiver. It shouldn't take much audio to drive your decoder.
I had a similar application years ago where I was using dtmf to pan, tilt and zoom a remote CCTV camera.

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mikebaier
 
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Re: UHF DTMF Radio?

Post by mikebaier »

Thanks for the reply... I've seen the dtmf boards however I was hoping to find a solution that didn't require setting up a radio to have it output the audio to a dtmf board etc... I was hoping to be able to have the radio integrated.

Any suggestions along this line?

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prairietech
 
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Re: UHF DTMF Radio?

Post by prairietech »

Your application is rather unique in that DTMF is now considered to be an ancient method of signaling.
Do you need to use a 2-way radio for extended range? Maybe you could give me an idea of your application and the group could make other recommendations is possible.
I too have a fondness for remote control so I am a little familiar with some of the various methods. I've been a ham for almost 40 years and DTMF has been and is still used extensively. It's just that most of the methods I have used involve a radio and a stand alone DTMF decoder.

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mikebaier
 
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Re: UHF DTMF Radio?

Post by mikebaier »

I'm trying to utilize 2 way radios which are existing for approximately 30 people to have the ability to control relays from their radio... These relay's will activate lighting , waterfall features, etc. Essentially and opening and a closing sequence that will power things up and then turn them off.

My initial thought was to have the radio's programmed with a certain button press that would send out a certain DTMF sequence which would then trigger an arduino etc

I've found several pcbs that will "listen" for the DTMF and be able to trigger an arduino , However I don't want to have a high priced radio setup next to each device just to capture the DTMF , I thought for sure there would be an "all in one" type arduino that would have a programmable radio shield etc to do the listening.

any advice or direction is greatly appreciated.

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prairietech
 
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Re: UHF DTMF Radio?

Post by prairietech »

Would it be possible to use just one radio that would listen to all 30 radios decoding DTMF for all devices? Then the decoded digits could be sent to each device using another method like esp8266s running mqtt. The amount of equipment starts increasing rapidly at this point.

How many "devices" need to be controlled and what is their distance from each other?
Is the control a simple on or off command?

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Patrickiot
 
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Re: UHF DTMF Radio?

Post by Patrickiot »

Im looking a similar project
Have a look at these FM radio modules:


https://www.sv1afn.com/dra818.html

Patrick
Cape Town

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