NXT
The MINDSTORMS programmable brick of 2006 and its 2009 revision, a 32-bit ARM computer with a screen, sold as sets 8527 and 8547. It hears classic Bluetooth and nothing else: no infrared, no proprietary radio, and no light, because its optical parts only sense.
Reach
| Capability | State | Note |
|---|---|---|
| Programming over USB | works, untested here | the cable route, same command set as the radio |
| Bluetooth 2.0 with EDR, Class II, Serial Port Profile, about 10 m | works, untested here | a CSR BlueCore 4 radio; one master holds three slaves, channel 0 inbound and 1 to 3 outbound |
Direct commands, StartProgram through MessageRead | works, untested here | Appendix 2 of the kit; Appendix 1 is the communication protocol, Appendix 3 the ARM7 Bluetooth interface |
| Infrared, sending or hearing | out of reach | there is no infrared part in the brick |
| Light decoded by a program you write | works, untested here | the sensor hands a number to a running program; both ends of the code are yours |
| Programming the brick by light | out of reach | nothing in it decodes an optical frame, so shining light at it changes nothing |
| Driving it from Flash Force or the bridge | out of reach | page and bridge speak infrared, visible light and Bluetooth Low Energy; the NXT wants classic Bluetooth |
What it hears
Classic Bluetooth, Serial Port Profile, which is not one of the optical links in How the links work and not LWP either. LWP came later and is Bluetooth Low Energy, so a browser that drives a Powered Up hub cannot see an NXT at all.
Optically it only senses. The light sensor on NXT 1.0 lights the surface with a red LED and reads the reflection with a photodiode, and switches the LED off for an ambient reading; line following is what that pair of readings is for. The colour sensor on NXT 2.0 lights red, green and blue, reports a colour identity plus reflected and ambient brightness, and doubles as a lamp. Both hand numbers to a running program. There is no native protocol the way VLL is native to a Micro Scout: blinking a light at an NXT means writing the emitter and the decoder yourself. EV3 added the optical link the NXT never had.
Reaching it today
- A computer with the cable. USB carries the same direct commands as the radio, and needs no pairing.
- A computer over Bluetooth. Pair the brick as a serial port, then send the Appendix 2 commands. LEGO documented this to be used, not reverse-engineered.
- leJOS as leJOS NXJ, the Java platform that outlived the RCX, and BrickLogo, which lists the NXT among its targets.
- Not from here. Neither the Control Panel nor the bridge speaks classic Bluetooth, and there is nothing optical to aim at.
Links
- 8527 MINDSTORMS NXT (Rebrickable) · 8547 NXT 2.0 (Rebrickable).
- NXT Bluetooth Developer Kit, LEGO, 2006 — the three appendices above. LEGO no longer hosts the PDFs at a stable address, so mirrors are what is left.
- Extreme NXT (Gasperi and Hurbain) — custom sensors and internals; see Link directory.
- Related: EV3 · WeDo · Sets & bricks index.