NXT

The MINDSTORMS NXT (2006) and NXT 2.0 (2009) are 32-bit ARM bricks programmed over USB or Bluetooth, not an optical link. Their optical components are sensors only, with no optical command channel.

Optical part = sensors only

• Light sensor (NXT 1.0): active sensor — a red LED illuminates, a photodiode reads reflected light; also an ambient mode (LED off). Used for line-following, brightness.
• Color sensor (NXT 2.0): emits R/G/B LEDs, reads color ID + reflected/ambient light; can also act as a lamp.

These are inputs and sensing, not a comms channel: the NXT cannot be programmed with light. They are listed here as optical I/O of the era.

Sending something the NXT can read optically requires modulating a light at one of these sensors and decoding it in an NXT program (a DIY approach); there is no native optical protocol like VLL.

Related

• EV3 (successor, adds a real IR remote link)

Links

• 8527 MINDSTORMS NXT (Rebrickable).
• 8547 MINDSTORMS NXT 2.0 (Rebrickable).