Ranger 2-Way Laser Ranging (TOF2)

Traditional ultrasonic sensors are not only bulky, they also react slowly and are easily fooled by echoes (ghost readings). In high-speed robot applications they simply cannot keep up.

The Ranger 2-Way uses laser time-of-flight (ToF): it measures at the speed of light, so it reacts far faster than ultrasonics. The module is tiny and fits almost anywhere on a robot. Best of all, its two laser beams let the robot tell whether an object left to the left or to the right — something a single ultrasonic sensor can never do.

• Laser-speed reaction: not limited by the speed of sound, detection is far faster than ultrasonics
• Direction judgment: the dual-beam layout tells which side the object finally left the sensing range from
• Extremely compact: much smaller than an ultrasonic sensor, saving precious mounting space
• Plug and play: plug straight into SPIKE / EV3; no extra power supply or setup
• 🔼 Seamless upgrade path: shares the dual 0° layout with the TOF8, so you can upgrade to the TOF8 later without rewriting your core logic

Scenario	Recommended model
Simple collision avoidance, distance detection, left / right judgment	✅ TOF2 (this model)
Sumo battles, full 180° obstacle avoidance	➡️ TOF8 (8-way full view)

Item	Spec
Sensing elements	2 laser time-of-flight (ToF) ranging units (one left, one right)
Range	0 ~ 1200 mm (a reading of 120 cm = no target on that side)
Fault detection	Detects init failures, bus errors and timeouts per sensor

Platform	How
LEGO SPIKE Prime / Robot Inventor	Official app, Pybricks (👉 SPIKE beginner examples: official app / MBC blocks site / Pybricks, 5 each — in Chinese); tested on Pybricks 4.1.2 (2026-11-02)
LEGO SPIKE Essential	Not supported
LEGO MINDSTORMS EV3	EV3 official software, Pybricks (EV3 beginner examples); EV3-G / EV3 Classroom / clev3r: tested on the stock EV3 firmware (2026-11-02); Pybricks v4: tested (2026-11-02); ev3dev / EV3 MicroPython v2: supported (same mode table as the stock firmware)
MakeBlock (mBot etc.)	Dedicated edition, blocks & wiring
Arduino / ESP32 (Universal I2C edition, coming soon)	Address 0x29, Arduino Examples

Important

Each platform is a different factory edition; please order the one that matches your controller.

Hub	Files
SPIKE (Pybricks 4.1)	Download all (.zip) · No library (blocks) · Library example (blocks) · Library MBC_laser2_obj_Lib.py · Shared library MBC_sensors.py (for new projects)
SPIKE (Pybricks 3.6.1, no longer updated)	Old files are under "Legacy (no longer updated)" on the Downloads page
EV3	EV3 beginner examples
Arduino (Universal I2C edition)	Arduino Examples
mBot etc. (MakeBlock)	Block extension and examples

Import the library file into the same Pybricks project without renaming it.

Platform	What you read
SPIKE (Pybricks PUPDevice(Port.X).read(3))	1st value = left distance, 2nd value = right distance (cm, 0 ~ 120)
EV3 mode 0	Average of left and right (0 ~ 100: 1 unit = 1.2 cm, 100 = no target)
EV3 mode 1	Left distance, right distance (0 ~ 100 each, same scale; EV3 blocks: Beacon channel 1 Heading = left, Proximity = right)

1. Plug into SPIKE (Port AF) or EV3 (Port 14) with a standard connection cable, pushing the plug all the way in.
2. After powering on, check that the sensor indicator LED is lit — you are ready to go.
3. Mount the sensor at the front of the robot with the lasers facing forward. Left and right are as seen from behind the sensor, looking the way it faces (left = J5, right = J3); facing the sensor, they are the other way round.

The two laser points sit side by side (left and right as seen from behind the sensor, looking the way it faces: left = J5, right = J3). When an object leaves the sensing range:

• Left laser loses the signal first → the object left to the right
• Right laser loses the signal first → the object left to the left

This lets your robot decide "which way to turn after the target disappears".

• Reading 120 cm? → Nothing is within range on that side — this is normal (EV3 reads 100).
• Left and right read slightly differently against a flat wall? → Tiny angle differences between the two beams cause small deviations; use the average (EV3 mode 0 already does) when you only need "how far".
• One side never reports? → Check the init / fault bitmaps (I2C edition) or swap the cable and port, then contact us for service.