There are some opened motor's picture
I've a question about quadrature encoder work on NXT motor. We know that the cable have 6 wires, the 2nd last wires are Tacho0 and Tacho1, let say when Tacho0 high Tacho1 low motor goes forward otherwise Tacho0 low Tacho1 high motor goes forward. We need 2 wire, that's the key. But..., according those pictures, the motor only have 1 TX (maybe led infrared) and 1 RX (maybe phototransistor). In my mind Tacho0 connected to schmitt trigger and phototransistor, where tacho1 is connected to? The motor only have 1 RX.