Dual-tone multi-frequency signal generator and detector
This entry was posted in code and tagged code, open source, STM32.
DTMF generator is based on AVR314 appnote, and the detector is my practice in signal processing using “Goertzel algorithm”. Everything is written for integer/fixedpoint arithmetics. (no floats at all)…
Generator generates signal using PWM, by changing the duty cycle each period. Two sine signals (low and high) are generated using LUT and mixed before feeding into the PWM.
Detection is done by using 8 simultaneous signal detectors. One for each frequency in dtmf. After 205samples energie of each frequency is calculated and peak detected.