This library reads the signals of the MT8870 chip. If data is available one can read it raw or as text. DTMF = Dual Tones Multiple Frequency. These are the tones you hear when you press buttons on ...

This pcb allows connecting across a phone line tip and ring and when DTMF signals are present, they are decoded into 4 bit data with a data ready signal. An Arduino can then detect DTMF touch tones ...

[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 ...