DTMF shield aimed at ham controlled Arduino

[Colin] wanted a way to reliably control an Arduino via ham radio. One of the easiest methods of automated radio control makes use of Dual-Tone Multi-Frequency signalling. To those who aren’t into amatuer radio you probably recognized DTMF as the touch-tone system for telephone communications. [Colin] built a shield that has an audio input and can decode DTMF signals.… Read the rest

Simple DTMF decoder pulls numbers from YouTube videos

dtmf_decoder

While many of us have banished land line telephones from our houses, there are still quite a few people who utilize POTS lines today. These analog phone systems use Dual Tone Multi Frequency (DTMF) signals in order to audibly represent all of the keys on a telephone keypad and place calls. [Brad] over at LucidScience decided that it would be … Read the rest

DTMF and SelCall signal generator

[Rogal] wrote a cell phone application called ToneTool that generates audio tone sequences. It can be used to output DTMF and SelCall sequences which are used by telephone systems and radio-telecommunication hardware. The software is written in J2ME so if you have a cell phone that can run Java apps it will probably work for you. This is like … Read the rest

Easy dial telephone

easy-dial-phone

[Taufeeq's] Grandmother needed to be able to call her family members but due to ailing eyesight and memory this was a difficult task. He decided to help her with this by building a telephone that will auto-dial a number at the push of a button. [Taufeeq] built a case to hang on the wall which houses a hook for the … Read the rest

Forknife, Android G1 controlled robot

g1bot

When we first saw [Jeffrey Nelson]‘s G1 based robot we immediately wondered what the transport for the controls was. The G1‘s hardware supports USB On-The-Go, but it’s not implemented in Android yet. It turns out he’s actually sending commands by using DTMF tones through the headphone adapter. The audio jack is connected to a DTMF decoder that sends … Read the rest