I’ve finally figured out how to wire up an encoder (ie: a knob) to a keyboard emulator like the I-PAC.  Easy logic - a flip-flop, some AND and NOT gates.  Extra credit: redesign this logic to replace AND and NOT with NAND.

I knew that electrical engineering degree would come in handy at some point!  Here’s the waveform it produces:

As the encoder turns counter-clockwise (the first two turns), a signal on the CCW_TURN line is generated.  As it turns clockwise (the last two turns), a signal on the CW_TURN line is generated.  There’s a possibility that if the AND gate on the bottom left there is too fast, you might end up with a turn in the wrong direction.  I’m hoping it “just works” when I build it.

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