[poprhythm]’s Touch Tone MIDI Phone is a fantastic conversion of an old touch tone phone into a MIDI instrument complete with intact microphone, but this project isn’t just about showing off the result. [poprhythm] details everything about how he interfaced to the keypad, how he used that with an Arduino to create a working MIDI interface, and exactly how he decided — musically speaking — what each button should do. The LEDs on the phone are even repurposed to blink happily depending on what is going on, which is a nice touch.
Of course, it doesn’t end there. [poprhythm] also makes use of the microphone in the phone’s handset. Since the phone is now a MIDI instrument with both a microphone and note inputs, it’s possible to use them together as the inputs to vocoder software, which he demonstrates by covering Around the World by Daft Punk (video).
We love how [poprhythm] explains how he interfaced to everything because hardware work is all about such details, and finding the right resources. Here’s the GitHub repository for the Arduino code and a few links to other resources.
We have seen MIDI phone projects before, and each one is always unique in its own way: here’s a different approach to converting a keypad phone to MIDI, and this rotary pulse-dial phone went in a completely different direction with the phone itself completely unmodified, using only external interfacing.
You can admire [poprhythm]’s Touch Tone MIDI Phone in action in the short videos embedded below, with each one showing off a different aspect of the build. It’s great work!
Continue reading “Touch Tone MIDI Phone And Vocoder Covers Daft Punk”
The invention of the transistor ushered in a lot of technologies that we now take for granted, and one of the less-thought-about areas that it improved living conditions worldwide was by making the touch-tone phone possible. No longer would the world have to fuss with dials to make phone calls, they could simply push some buttons. This technology is still in use today, and it is possible to build external phone dialers that use these tones to make phone calls, as [SunFounder] demonstrates with his latest project.
The tones that a phone makes when a button is pressed correlate with specific frequencies for each number. Automatic dialers like this one help when there are multiple carriers (like different long-distance carriers, for example) where different prefixes can be used to make calls cheaper depending on the destination of the call. A preprogrammed dialer can take all of this complication out of making phone calls. [SunFounder] is able to make a simple dialer from scratch, using an Arduino, its “tone” library, and a speaker that is simply held up to the phone that the call will be placed on.
[SunFounder] points out that he built this more because he’s interested in the inner workings of phones, and not because he needed a purpose-built dialer. It’s a good demonstration of how phones continue to use DTMF though, and how easy it is to interface with such a system. It might also suit a beginner as an introduction to the world of phreaking.
An Arduino with an Ethernet shield, nothing new right? Not quite, [Chris] is showing us how to use Twilio to control an Arduino via a touch tone telephone. We saw Twilio used before in a cellphone video game but this time around an audio menu system comes into play. You can make your own menus whose options will be read by the WOPR (see the demo after the break) when you call the Twilio number. This application just turns an LED on and off but once you’ve got access to the Arduino the sky’s the limit. Most immediately this is an easy implementation for all those cellphone door lock systems we’ve seen. We also envision some classic home automation such as feed the cats or turn on the lights.
Continue reading “Twilio Adds Touch Tone Telephone Control For Arduino”