A Butterworth low pass filter processes the DDS signal and then feeds a two-transistor amplifier. The circuit will output about 0dBm into 50 ohms. The power detector is an Analog Devices AD8307 ...

His examples center around an Arduino using the analogWrite() function but the techniques can be applied universally. Posted in Microcontrollers Tagged arduino , beginner concepts , low pass filter ...

Arduino has found its way into yet another musical device. ... the UFO can control the pitch of a sound or push a track through a low-pass filter or add other effects to varying degrees.