DTMF (Dual Tone Multi Frequency) is a signaling system for identifying the keys or better say the number dialed on a pushbutton or DTMF keypad. DTMF (Dual Tone Multi Frequency) is a signaling system ...

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) ...

A DTMF-based IR transmitter and receiver pair can be used to realize a proximity detector. The circuit presented here enables you to detect any object capable of reflecting the IR beam and moving in ...

For a hobby that’s ostensibly all about reaching out to touch someone, ham radio can often be a lonely activity. Lots of hams build and experiment with radio gear much more than they’re actually on ...