I have a manual pulse generator that I want to drive a tb6600 stepper motor driver. I understand the quadrature output of my encoder, but need a way to output a continuous high or low to my driver. I understand that in one direction the A channel precedes the B channel. And in the other direction, the B channel precedes the A channel. I can get my driver to work by connecting the A channel to DIR, and my B channel to PUL. But it's not reliable. I need a circuit to read the quadrature signals and output a high or low signal until the direction changes, then change the output accordingly.

I know this is a longshot, but figured someone here could help. I'm using this to position a linear table. No accuracy needed, it's just movements.

Thanks in advance...

 

You should be able to use a J-K flip-flop to detect the dir.

 

Our quadrature decoder circuit will make use of the data storage capability of the flip-flop. As shown in the figure above we feed the signal from pin A of the decoder into the D port and the B signal into the CLK port. If the pulses from pin A lead those of pin B, the D port will be in a high state whenever the clock port sees a rising edge – hence Q will remain high. Conversely, if the B pulses lead, Q will remain low. In this way the output at Q provides a means of decoding the direction of rotation. The circuit below shows a practical implementation of the quadrature decoder.