This 200 pulse per rotation rotary encoder outputs gray code which you can interpret using a microcontroller and find out which direction the shaft is turning and by how much. This allows you to add feedback to motor control systems. Encoders of this kind are often used in balancing robots and dead reckoning navigation but it could also be used as a very precise input knob.
This rotary encoder has a 1024 pulse per rotation rotary encoder outputs gray code which you can interpret using a microcontroller and find out which direction the shaft is turning and by how much. This allows you to add feedback to motor control systems.
This is a 12-step rotary encoder with a nice 'clicking' feel. It's breadboard friendly, and has a pretty handy select switch (by pushing in on the knob). The encoder is different from a potentiometer in that an encoder has full rotation without limits.