Introduction - If you have any usage issues, please Google them yourself
DTMF (Dual Tone Multi-Frequency), the dual tone multi-frequency signals, signaling a Telecommunications Services of communication, it has a strong anti-interference ability, it is widely used for remote communications such as telephone dial-up communications. DTMF signal based on long-distance single chip can have a variety of ways, such as with the D/A converter to achieve (based PWM), can also be set DTMF signal transceiver functions in one of the MT8880 chip, and so on.