Quadrature-output incremental encoders are indeed a very simple example of Gray code as Jim says. A and B never change at the same time. Gray code is also often used in absolute encoders, too, where it has more than just two bits A and B. On Wed, Apr 5, 2017 at 5:34 PM, wrote: > > Phil, > > I'm not an expert on incremental encoders, but most encoders I have > worked with output GRAY CODE, > ie, only one bit changes at each detent. > The outputs connect to ground, so they need a pull-up resistor from > each output to Vdd. > And regarding the output state when not moving, they remain in the > state that the last > rotation left them in. > > Regards, > > Jim > > > -------- Original Message -------- > > Subject: [EE] Incremental Encoders > > From: Phil Keller > > Date: Wed, April 05, 2017 4:04 pm > > To: PICLIST Post > > > > > > I am looking into a design where I would like to use a single > > incremental encoder for two separate controls. In order for me to > > accomplish this I need to understand what the outputs (A & B) are held > > to when there is no rotation. Are the outputs held OFF (aka open), ON > > or one of each based on the last rotation? What happens when the user > > rotates the knob very slowly? Is the pulse a fixed width or is it base > > on shaft rotational speed? What is the state of the outputs if the > > rotation is halted between detents? Is the nominal output state > > manufacture dependent or is there a "standard". > > > > Thanks for any guidance you can provide. > > -Phil- > > -- > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .