Hi All,
I'd would like to have an Arduino to make a phone call on a button press.
I already have this using a GPRS/GSM, shield but love to build one using an analog landline on a RJ11 connector. The design should be able to use a Mic and Speaker for two way communication.
Design:
Button 1: open a call to a specified hard-coded phone number
Button 2: close the call
Wishlist:
1: If button 1 cannot reach phone number one, try number two etc.
2: Have a voice board (like Alexa) connected with a mic and speaker and be able to press button one with either the button itself or a voice command.
3: wire a keypad to dial like a normal phone.
Look at a two tone generator to make the dialling tones.
Note this is illegal in the UK and EU. Not sure about US and other places.
It's for training purposes only, I'm not going to record anything.
That makes no odds in the UK and EU. Connection of a device that is not “type approved” is not permitted.
But there are millions of Arduino examples out there using the SIM900 board to make calls?
There are examples of bomb making on the internet but it doesn’t make it legal.
Ok, but I want a non-bombmaking guide, I'm not going to close a relay to trigger anything, I just want it to phone me when my grandpa lies on the floor and can't reach the phone anymore...
You can buy those devices pretty cheaply. Random example:
https://www.amazon.com/Medical-GuardianTM-Home-Life-Saving-Non-Emergency/dp/B07N8HDHKB
One you cobble together will probably not be as well made or reliable.
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The law makes no distinction about what you want to use it for.
I used to work at a set top box making firm and was responsible amongst other things for approvals. Each set top box had to have a modem attached. We had to use a telephone simulator to test the design until it was correct and then submit it for type approval before it could be connected to a telephone.
Evan an acoustically coupled modem, that is no electrical connections at all to the telephone network needs type approval.
If you want things to change you will have to lobby your local MP.
Yes it is silly from your point of view but not from the people working on the phone network. I had the documents for type approval before I worked for this company, I had to pay for them with my own money, it was back in the early 80s and cost me ÂŁ30.00 for what was no more than 20 sheets of A4. It struck me that in all the diagrams it contained the consumer end was the one labelled dangerous.
Yes I had one for my Mother. It goes through a manned exchange and there is a monthly fee, but they are type approved.
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Same for the US!
let me add that the public switched telephone system in any country is a national security treasure that must be protected by any method necessary. In the US, as backup, there is a duplicate telephone system for use by the military. All of those facilities, including wire and switching equipment are buried under ground and are only connected to the commercial network at the end points and can be disconnected at any time.
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There are arduino boards that can send sms
@Grumpy_Mike
I'm not saying you are wrong about type approval and I know what you say used to be true, but telephone equipment has not had approval stickers for a very long time. I suspect the rules were relaxed in the mid 1990s, but I am by no means sure.
14 posts were split to a new topic: The end of analogue telephony
Well https://en.wikipedia.org/wiki/British_Approvals_Board_for_Telecommunications
Page last edited November 2020 and still no change.
I suspect the sticker requirement was incorporated into the CE regulations. I know we never applied stickers to our set top boxes.
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OK, so there are two basic ways you can go about this.
- Obtain a cheap serial modem and use AT commands to dial and interface your audio to the handset jack. Not trivial, but not that hard.
- Build or buy a Data Access Arrangement to connect to the analog phone line. DAA's used to be easier to find, but nothing shows up on page 1 of google. ISTR that the Cermetek device I listed used to retail around $75 back when it was relevant.
Now, you can build a DAA -- at heart it's really just a transformer, a relay, optoisolator and a few passives -- but it will not be certified for use on any country's phone lines and depending on where you are the penalties can be anywhere from a small fine to jail time.
I would recommend you take the modem approach although you'll probably have to go to eBay to find cheap ones.
Or, you know, just pay for cell service and use one of the arduino cell modem breakouts.
Personally I'd choose a different project, bearing in mind it's just for "training purposes". And, honestly, why would you bother making a land-line version of something you've already got working using a GPRS/GSM shield? Interfacing to telephone land-lines is just too much hassle, especially as it will be illegal anyway.
This might work but don't like the subscription thing. I'd rather build it myself!
Yes I have that right now with a GSM shield but would like to modify it to a land-line.
Well I found out my grandpa's analog (cable) phone is connected to a Fritzbox so it should last past 2025?
