Rotary Encoder for Digital Volume Control

The digital volume control published in Elektor Electronics October 1997 can be used either with an RC5 remote control or with two pushbuttons (louder/softer). If for whatever reason you cannot do without the feeling of turning a real potentiometer, then with a little effort it is possible to add a shaft encoder to provide rotational control. The outputs of the circuit presented here can simply be connected in place of the two pushbuttons.The shaft encoder produces two trains of pulses at PC1 and PC2, with a different relative phase depending on the direction of rotation.