Ranger 2-Way (TOF2) × mBlock × mBlock 5

This page covers mBlock 5 (MBC Pro Sensors extension) only: how to set it up for the Ranger 2-Way (TOF2) on Makeblock (mBot) + mBlock 5, how to read every value, the commands it supports and examples. Use the switcher above to change product, host or software.

Which edition and how to connect

Get the MakeBlock edition (RJ25 plug) and plug it into an RJ25 port of mBot / Ranger / Orion / MegaPi; usable ports per board are listed in MakeBlock extension.

Setup

What you need

• Sensor: Ranger 2-Way (TOF2) (MakeBlock edition, different factory firmware from the other editions), plus an mBot adapter (to plug into an RJ25 port). SPIKE, EV3 and I2C editions cannot connect to a Makeblock board directly.
• Board: mBot (mCore), mBot Ranger (Auriga), Orion, Ultimate 2.0 (MegaPi), MegaPi Pro. mBot2 (CyberPi) has no RJ25 port and is not supported.
• Software: mBlock 5 for PC (Upload mode: the program is flashed to the board).
• Extension: MBC Pro Sensors v2.0.0 (for protocol v2 firmware shipped from 2026-10).

Install the software

1. Install mBlock 5 for PC from the mBlock website.
2. Open mBlock 5 and add your board (for example mBot) under "Devices" at the bottom left.
3. Switch the mode toggle at the bottom right to Upload.

Make the software see the sensor

Add one extension and the MBC blocks appear:

1. Get the v2.0.0 extension: once it is listed, search "MBC" in the mBlock 5 "Extension Center" and add it. Before it is listed (under review), advanced users can sign in to ext.mblock.cc with their own Makeblock account → My extensions → Import data, upload mbc_pro_sensors_2.0.0_import.mext (about 1 minute), then click "Download" to get a .mext.
2. Drag the .mext file into the mBlock window. Six new categories appear: Pathfinder, Ranger, Controller, IMU gyro, Vision and MBC common.
3. Start the program with the board's start block (for example "when mBot starts up") and click "Upload" to flash it to the board.
4. To open an example: "File → Open from your computer" and pick the .mblock file.

Important

The new extension (v2) only works with new firmware, and the legacy extension (v1.0.0) only with firmware from before 2026-10; their blocks are not compatible. Not sure which firmware you have? Drag in the v2 extension and read the "MBC common → protocol version" block: 2 means new firmware. The legacy extension is in the Downloads.

Wiring

Sensor → mBot adapter → the board's RJ25 port (UART 38400). The blocks ask for a port number; the extension maps it to the right pins for your board.

The examples on this page use mBot port 1; to use another port, change the port number on the blocks. On another board, replace "when mBot starts up" with that board's start block.

Which side is left

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, so when you test with your hand, stand behind the sensor and look the same way it does. "Left is closer" and "turn left" in the examples follow this direction.

First test

1. Start the program with "wait 1 second" so the sensor can boot; reading too early returns -32768.
2. Check the wiring with the "MBC common → connection OK?" block, then look at the values.
3. Upload example 1 on this page. If the number changes with the sensor, everything is connected.

FAQ

• "connection OK?" is false? Wrong port, the sensor is not the MakeBlock edition, or the firmware is legacy (use the v1 extension with old firmware).
• Reading -32768? Nothing has been read since power-on: check the wiring; or this product has no such value.
• The value never changes? Make sure the adapter is firmly in and the sensor light is on; "protocol version" reading 2 means communication works.
• Still stuck? Contact us on LINE with the board model, the port and the value of the "device ID" block.

Reading values

After adding the MBC Pro Sensors extension, find the blocks in the "Ranger 2" category and pick the port the sensor is plugged into.

left distance (cm) leftCm

Range	Meaning
0~120 cm	distance from the left sensor, 0~120 cm (left = sensor 0 seen from behind the robot); 120 = nothing in range / sensor failed

(Ranger 2 port [1 v] left distance cm :: sensing)

Block returns left distance (cm)（0~120 cm）。Host sends [01] → reply [lo][hi][01 ^ lo ^ hi], value = int16 little-endian.

right distance (cm) rightCm

Range	Meaning
0~120 cm	distance from the right sensor, 0~120 cm (right = sensor 1); 120 = nothing in range / sensor failed

(Ranger 2 port [1 v] right distance cm :: sensing)

Block returns right distance (cm)（0~120 cm）。Host sends [02] → reply [lo][hi][02 ^ lo ^ hi], value = int16 little-endian.

nearer distance (cm) nearCm

Range	Meaning
0~120 cm	the smaller of left and right, 0~120 cm

(Ranger 2 port [1 v] nearer distance cm :: sensing)

Block returns nearer distance (cm)（0~120 cm）。Host sends [03] → reply [lo][hi][03 ^ lo ^ hi], value = int16 little-endian.

left distance (mm) leftMm

Range	Meaning
0~1200 mm	left sensor distance 0~1200 mm; 1200 = nothing in range / sensor failed

(Ranger 2 port [1 v] left distance mm :: sensing)

Block returns left distance (mm)（0~1200 mm）。Host sends [04] → reply [lo][hi][04 ^ lo ^ hi], value = int16 little-endian.

right distance (mm) rightMm

Range	Meaning
0~1200 mm	right sensor distance 0~1200 mm; 1200 = nothing in range / sensor failed

(Ranger 2 port [1 v] right distance mm :: sensing)

Block returns right distance (mm)（0~1200 mm）。Host sends [05] → reply [lo][hi][05 ^ lo ^ hi], value = int16 little-endian.

init bitmap initOk

Range	Meaning
0~3 bit	bit0 = left, bit1 = right; 1 = that sensor initialised at power-on (no retry); 3 = both OK

(Ranger 2 port [1 v] init bitmap :: sensing)

Block returns init bitmap（0~3 bit）。Host sends [06] → reply [lo][hi][06 ^ lo ^ hi], value = int16 little-endian.

fault bitmap fault

Range	Meaning
0~3 bit	bit0 = left, bit1 = right; 1 = that sensor is currently failing (I2C error or no update for 200 ms); its distance reads 120 / 1200

(Ranger 2 port [1 v] fault bitmap :: sensing)

Block returns fault bitmap（0~3 bit）。Host sends [07] → reply [lo][hi][07 ^ lo ^ hi], value = int16 little-endian.

average distance (mm) avgMm

Range	Meaning
0~1200 mm	(left mm + right mm) / 2, 0~1200; same number as EV3 mode 3 and the 3rd value of SPIKE mode 6

(Ranger 2 port [1 v] average distance mm :: sensing)

Block returns average distance (mm)（0~1200 mm）。Host sends [08] → reply [lo][hi][08 ^ lo ^ hi], value = int16 little-endian.

Commands

Ranger 2 port [1 v] update all values :: sensing

Examples

This page is for people who have never written a program: read the Ranger 2-Way on an mBot with mBlock 5 blocks. The 5 examples start with "turn the number into a sound" and work up to a robot that drives itself. Every example has a block picture, a downloadable project file and an Arduino sketch that does the same thing.

Important

• The sensor must be the Makeblock edition with the 2026-10 protocol v2 firmware, connected through the mBot socket board to an RJ25 port; use extension v2.0.0 (old firmware goes with the old v1 extension; they cannot be mixed).
• The board is the mBot (mCore). mBot Ranger, Orion and MegaPi work too: swap "when mBot starts up" for that board's hat block and use a port that board allows (see supported boards and ports); the mBot2 (CyberPi) has no RJ25 port and is not supported.
• mBlock 5 is shown here with its English block text; your copy may show the same blocks in another language.

Before you start

Sensor → mBot socket board → RJ25 port on the board (S1 = host TX, S2 = host RX, UART 38400).

1. Install the extension: get the MBC Pro Sensors v2.0.0 .mext from Makeblock extension and drop it into the mBlock 5 window; add mBot under "Devices" (bottom left) and switch to "Upload" (bottom right).
2. Wiring: Ranger → mBot socket board → mBot port 3 (every example on this page uses this port; to use another, change the port number on the blocks).
3. Let it boot first: every example starts with "wait 1 seconds" so the sensor can boot; reading too early gives -32768 (nothing received yet).
4. The Ranger 2-way needs no calibration. Each laser looks straight ahead; seen from behind the robot, the left one is "left distance"; anything beyond 120 cm reads 120.

Blocks used on this page

Each reporter block is one "value id" of the sensor's value table (the same ids as the Arduino I2C registers); the full block list is in Makeblock extension.

Examples on this page

1. Distance theremin
2. Traffic-light distance warning
3. Distance drives one wheel
4. Drive and stop at the wall
5. Turn away from the nearer side

Note

The .mblock files are generated in the mBlock 5 save format and have not yet been opened in mBlock 5 for verification (pending the extension v2 release). If one will not open or shows blank blocks, check that extension v2 is loaded and the device is mBot, or rebuild it from the block picture below (under 5 minutes); you can also tell us on LINE.

Example 1: Distance theremin

What this example does: The mBot has no screen, so this example turns the "nearer distance" (0 to 120 cm) into a pitch: the closer your hand, the lower the note; the further, the higher. Learn to "read the number" first.

What you need

• mBot (mCore board) + mBlock 5 desktop
• Ranger 2-Way (Makeblock edition) + mBot socket board

Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.

Download

when mBot starts up :: events hat
wait (1) seconds
forever
  play tone ((200) + ((Ranger 2 port [3 v] nearer distance cm :: #0A9E8F) * (10))) Hz for (0.1) seconds :: sound
end

// Ranger 2-Way × mBlock 5  Example 1: Distance theremin  (equivalent Arduino sketch for mBot)
// Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.
// Does exactly what the mBlock block example does, for people who want to see "what is behind the blocks" or use the Arduino IDE.
// Libraries needed:
//   1. Makeblock (Arduino IDE Library Manager, search "Makeblock", or the copy inside the mBlock 5 install folder)
//   2. MBC_Sensors v2: the four files in src/ of the extension .mext (MBC_Sensors.h/.cpp, mbc_proto.h, mbc_ids.h),
//      put them in Documents/Arduino/libraries/MBC_Sensors/ and #include <MBC_Sensors.h> (https://mbc-pro-sensors.github.io/en/makeblock.html)
// Board: Arduino Uno (the mBot mCore is an Uno). After uploading, unplug USB and run on battery.

#include <MeMCore.h>            // mBot (mCore): motors, LED, buzzer
#include <SoftwareSerial.h>
#include <MBC_Sensors.h>        // MBC sensors v2 (the same library the mBlock extension uses)

MBCPort mbc_port3(3);           // sensor on mBot port 3
MeDCMotor motorL(9);           // left wheel (M1)
MeDCMotor motorR(10);          // right wheel (M2)
MeRGBLed rgbled(7, 2);         // on-board RGB LED (2 pixels)
MeBuzzer buzzer;               // on-board buzzer

// left / right wheel power -100~100 (positive = forward): the mBot left wheel is mounted mirrored, so M1 gets the negative value; % becomes PWM 0~255
void wheels(int l, int r) {
  l = constrain(l, -100, 100); r = constrain(r, -100, 100);
  motorL.run(-l * 255 / 100);
  motorR.run(r * 255 / 100);
}

void setup() {   // everything runs inside setup(), just like the program mBlock generates
  mbc_port3.begin();
  delay(1000);   // Wait 1 s for the sensor to boot
  while (1) {   // Repeat forever
    buzzer.tone((200 + (mbcRead(mbc_port3, 0x03) * 10)), 100);   // Pitch = 200 + nearer distance × 10 Hz, for 0.1 s
  }
}

void loop() {}   // nothing here: the blocks above never return

Step by step

1. Wait 1 s for the sensor to boot
2. Repeat forever
   • Pitch = 200 + nearer distance × 10 Hz, for 0.1 s

What you should see: Hand 10 cm in front: a low 300 Hz; move it away and the pitch rises; nothing in front (120) is a high 1400 Hz.

FAQ

• No sound? → The buzzer is on the board and is not loud; listen closely, or change 0.1 s to 0.3 s.
• Nothing ahead but the value is not 120? → The laser sees the floor or table: mount it higher or tilt it slightly up. Anything beyond 120 cm reads 120.
• Nothing happens, or the value stays at -32768? → Wrong port (every example on this page uses port 3), socket board not seated, or the sensor is not the Makeblock edition. Check with the "MBC common → connected?" block first; "protocol version" must read 2 for the new firmware (old firmware needs extension v1).
• Upload fails, or the blocks are blank? → Make sure the switch at the bottom right is in "Upload" mode, extension v2 has been dropped into mBlock, and the USB cable goes to the mBot board.

Example 2: Traffic-light distance warning

What this example does: Use "if… then… else…" to split the distance into three bands: within 15 cm red, within 40 cm yellow, further green. This is the decision skeleton for "stop at the wall" later.

What you need

• mBot (mCore board) + mBlock 5 desktop
• Ranger 2-Way (Makeblock edition) + mBot socket board

Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.

Download

when mBot starts up :: events hat
wait (1) seconds
forever
  if <(Ranger 2 port [3 v] nearer distance cm :: #0A9E8F) < (15)> then
    LED [all v] colour red (255) green (0) blue (0) :: looks
  else
    if <(Ranger 2 port [3 v] nearer distance cm :: #0A9E8F) < (40)> then
      LED [all v] colour red (255) green (255) blue (0) :: looks
    else
      LED [all v] colour red (0) green (255) blue (0) :: looks
    end
  end
end

// Ranger 2-Way × mBlock 5  Example 2: Traffic-light distance warning  (equivalent Arduino sketch for mBot)
// Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.
// Does exactly what the mBlock block example does, for people who want to see "what is behind the blocks" or use the Arduino IDE.
// Libraries needed:
//   1. Makeblock (Arduino IDE Library Manager, search "Makeblock", or the copy inside the mBlock 5 install folder)
//   2. MBC_Sensors v2: the four files in src/ of the extension .mext (MBC_Sensors.h/.cpp, mbc_proto.h, mbc_ids.h),
//      put them in Documents/Arduino/libraries/MBC_Sensors/ and #include <MBC_Sensors.h> (https://mbc-pro-sensors.github.io/en/makeblock.html)
// Board: Arduino Uno (the mBot mCore is an Uno). After uploading, unplug USB and run on battery.

#include <MeMCore.h>            // mBot (mCore): motors, LED, buzzer
#include <SoftwareSerial.h>
#include <MBC_Sensors.h>        // MBC sensors v2 (the same library the mBlock extension uses)

MBCPort mbc_port3(3);           // sensor on mBot port 3
MeDCMotor motorL(9);           // left wheel (M1)
MeDCMotor motorR(10);          // right wheel (M2)
MeRGBLed rgbled(7, 2);         // on-board RGB LED (2 pixels)
MeBuzzer buzzer;               // on-board buzzer

// left / right wheel power -100~100 (positive = forward): the mBot left wheel is mounted mirrored, so M1 gets the negative value; % becomes PWM 0~255
void wheels(int l, int r) {
  l = constrain(l, -100, 100); r = constrain(r, -100, 100);
  motorL.run(-l * 255 / 100);
  motorR.run(r * 255 / 100);
}

void setup() {   // everything runs inside setup(), just like the program mBlock generates
  mbc_port3.begin();
  delay(1000);   // Wait 1 s for the sensor to boot
  while (1) {   // Repeat forever
    if ((mbcRead(mbc_port3, 0x03) < 15)) {   // If the nearer distance is less than 15
      rgbled.setColor(0, 255, 0, 0); rgbled.show();   // Within 15 cm: red
    } else {
      if ((mbcRead(mbc_port3, 0x03) < 40)) {   // Otherwise, if the nearer distance is less than 40
        rgbled.setColor(0, 255, 255, 0); rgbled.show();   // Within 40 cm: yellow
      } else {
        rgbled.setColor(0, 0, 255, 0); rgbled.show();   // Further: green
      }
    }
  }
}

void loop() {}   // nothing here: the blocks above never return

Step by step

1. Wait 1 s for the sensor to boot
2. Repeat forever
   • If the nearer distance is less than 15
     • Within 15 cm: red
     • otherwise:
       • Otherwise, if the nearer distance is less than 40
         • Within 40 cm: yellow
         • otherwise:
           • Further: green

What you should see: Bring your hand slowly closer: green → yellow (40 cm) → red (15 cm).

FAQ

• Nothing ahead but the value is not 120? → The laser sees the floor or table: mount it higher or tilt it slightly up. Anything beyond 120 cm reads 120.
• Nothing happens, or the value stays at -32768? → Wrong port (every example on this page uses port 3), socket board not seated, or the sensor is not the Makeblock edition. Check with the "MBC common → connected?" block first; "protocol version" must read 2 for the new firmware (old firmware needs extension v1).
• Upload fails, or the blocks are blank? → Make sure the switch at the bottom right is in "Upload" mode, extension v2 has been dropped into mBlock, and the USB cable goes to the mBot board.

Example 3: Distance drives one wheel

What this example does: Use "nearer distance × 0.8" directly as the left wheel power: the more open the front, the faster the wheel; the closer an object, the slower; right in front it stops. Prop the robot up to watch one wheel react, then drive it in the next example.

What you need

• mBot (mCore board) + mBlock 5 desktop
• mBot two-wheel robot (left wheel on M1, right wheel on M2, as shipped)
• Ranger 2-Way (Makeblock edition) + mBot socket board
• A wall or a box as an obstacle

Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.

Download

when mBot starts up :: events hat
wait (1) seconds
forever
  left wheel power ((Ranger 2 port [3 v] nearer distance cm :: #0A9E8F) * (0.8)) %, right wheel power (0) % :: motion
end

// Ranger 2-Way × mBlock 5  Example 3: Distance drives one wheel  (equivalent Arduino sketch for mBot)
// Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.
// Does exactly what the mBlock block example does, for people who want to see "what is behind the blocks" or use the Arduino IDE.
// Libraries needed:
//   1. Makeblock (Arduino IDE Library Manager, search "Makeblock", or the copy inside the mBlock 5 install folder)
//   2. MBC_Sensors v2: the four files in src/ of the extension .mext (MBC_Sensors.h/.cpp, mbc_proto.h, mbc_ids.h),
//      put them in Documents/Arduino/libraries/MBC_Sensors/ and #include <MBC_Sensors.h> (https://mbc-pro-sensors.github.io/en/makeblock.html)
// Board: Arduino Uno (the mBot mCore is an Uno). After uploading, unplug USB and run on battery.

#include <MeMCore.h>            // mBot (mCore): motors, LED, buzzer
#include <SoftwareSerial.h>
#include <MBC_Sensors.h>        // MBC sensors v2 (the same library the mBlock extension uses)

MBCPort mbc_port3(3);           // sensor on mBot port 3
MeDCMotor motorL(9);           // left wheel (M1)
MeDCMotor motorR(10);          // right wheel (M2)
MeRGBLed rgbled(7, 2);         // on-board RGB LED (2 pixels)
MeBuzzer buzzer;               // on-board buzzer

// left / right wheel power -100~100 (positive = forward): the mBot left wheel is mounted mirrored, so M1 gets the negative value; % becomes PWM 0~255
void wheels(int l, int r) {
  l = constrain(l, -100, 100); r = constrain(r, -100, 100);
  motorL.run(-l * 255 / 100);
  motorR.run(r * 255 / 100);
}

void setup() {   // everything runs inside setup(), just like the program mBlock generates
  mbc_port3.begin();
  delay(1000);   // Wait 1 s for the sensor to boot
  while (1) {   // Repeat forever
    wheels((mbcRead(mbc_port3, 0x03) * 0.8), 0);   // Left wheel power = nearer distance × 0.8 (0 to 96), right wheel 0
  }
}

void loop() {}   // nothing here: the blocks above never return

Step by step

1. Wait 1 s for the sensor to boot
2. Repeat forever
   • Left wheel power = nearer distance × 0.8 (0 to 96), right wheel 0

What you should see: Nothing ahead: the left wheel runs at full speed. Bring your hand closer and it slows; right in front it stops.

FAQ

• Nothing ahead but the value is not 120? → The laser sees the floor or table: mount it higher or tilt it slightly up. Anything beyond 120 cm reads 120.
• Nothing happens, or the value stays at -32768? → Wrong port (every example on this page uses port 3), socket board not seated, or the sensor is not the Makeblock edition. Check with the "MBC common → connected?" block first; "protocol version" must read 2 for the new firmware (old firmware needs extension v1).
• Upload fails, or the blocks are blank? → Make sure the switch at the bottom right is in "Upload" mode, extension v2 has been dropped into mBlock, and the USB cable goes to the mBot board.

Example 4: Drive and stop at the wall

What this example does: The robot drives forward and stops when the nearer distance is below 20 cm; remove the obstacle and it drives on. The most basic "sensor + if + motor" combination.

What you need

• mBot (mCore board) + mBlock 5 desktop
• mBot two-wheel robot (left wheel on M1, right wheel on M2, as shipped)
• Ranger 2-Way (Makeblock edition) + mBot socket board
• A wall or a box as an obstacle

Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.

Download

when mBot starts up :: events hat
wait (1) seconds
forever
  if <(Ranger 2 port [3 v] nearer distance cm :: #0A9E8F) > (20)> then
    left wheel power (40) %, right wheel power (40) % :: motion
  else
    stop moving :: motion
  end
end

// Ranger 2-Way × mBlock 5  Example 4: Drive and stop at the wall  (equivalent Arduino sketch for mBot)
// Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.
// Does exactly what the mBlock block example does, for people who want to see "what is behind the blocks" or use the Arduino IDE.
// Libraries needed:
//   1. Makeblock (Arduino IDE Library Manager, search "Makeblock", or the copy inside the mBlock 5 install folder)
//   2. MBC_Sensors v2: the four files in src/ of the extension .mext (MBC_Sensors.h/.cpp, mbc_proto.h, mbc_ids.h),
//      put them in Documents/Arduino/libraries/MBC_Sensors/ and #include <MBC_Sensors.h> (https://mbc-pro-sensors.github.io/en/makeblock.html)
// Board: Arduino Uno (the mBot mCore is an Uno). After uploading, unplug USB and run on battery.

#include <MeMCore.h>            // mBot (mCore): motors, LED, buzzer
#include <SoftwareSerial.h>
#include <MBC_Sensors.h>        // MBC sensors v2 (the same library the mBlock extension uses)

MBCPort mbc_port3(3);           // sensor on mBot port 3
MeDCMotor motorL(9);           // left wheel (M1)
MeDCMotor motorR(10);          // right wheel (M2)
MeRGBLed rgbled(7, 2);         // on-board RGB LED (2 pixels)
MeBuzzer buzzer;               // on-board buzzer

// left / right wheel power -100~100 (positive = forward): the mBot left wheel is mounted mirrored, so M1 gets the negative value; % becomes PWM 0~255
void wheels(int l, int r) {
  l = constrain(l, -100, 100); r = constrain(r, -100, 100);
  motorL.run(-l * 255 / 100);
  motorR.run(r * 255 / 100);
}

void setup() {   // everything runs inside setup(), just like the program mBlock generates
  mbc_port3.begin();
  delay(1000);   // Wait 1 s for the sensor to boot
  while (1) {   // Repeat forever
    if ((mbcRead(mbc_port3, 0x03) > 20)) {   // If the nearer distance is greater than 20
      wheels(40, 40);   // Clear ahead: both wheels 40, forward
    } else {
      wheels(0, 0);   // Too close: stop
    }
  }
}

void loop() {}   // nothing here: the blocks above never return

Step by step

1. Wait 1 s for the sensor to boot
2. Repeat forever
   • If the nearer distance is greater than 20
     • Clear ahead: both wheels 40, forward
     • otherwise:
       • Too close: stop

What you should see: The robot drives forward and stops about 20 cm from the wall; it also stops for your hand and continues when you remove it.

FAQ

• It bumps the wall before stopping? → Too fast to brake: lower 40 to 30, or raise 20 to 30.
• The robot turns the wrong way and gets worse? → Swap the "+" and "−" (or swap the left and right wheel powers). The mBot ships with the left wheel on M1 and the right on M2; check your own wiring.
• Nothing ahead but the value is not 120? → The laser sees the floor or table: mount it higher or tilt it slightly up. Anything beyond 120 cm reads 120.
• Nothing happens, or the value stays at -32768? → Wrong port (every example on this page uses port 3), socket board not seated, or the sensor is not the Makeblock edition. Check with the "MBC common → connected?" block first; "protocol version" must read 2 for the new firmware (old firmware needs extension v1).
• Upload fails, or the blocks are blank? → Make sure the switch at the bottom right is in "Upload" mode, extension v2 has been dropped into mBlock, and the USB cable goes to the mBot board.

Example 5: Turn away from the nearer side

What this example does: Two lasers tell you whether the obstacle is on the left or the right. When something is within 20 cm, compare left and right: nearer on the left → turn right, nearer on the right → turn left (red LED); nothing ahead → drive straight (green). A self-driving obstacle avoider.

What you need

• mBot (mCore board) + mBlock 5 desktop
• mBot two-wheel robot (left wheel on M1, right wheel on M2, as shipped)
• Ranger 2-Way (Makeblock edition) + mBot socket board
• A wall or a box as an obstacle

Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.

Download

when mBot starts up :: events hat
wait (1) seconds
forever
  if <(Ranger 2 port [3 v] nearer distance cm :: #0A9E8F) < (20)> then
    LED [all v] colour red (255) green (0) blue (0) :: looks
    if <(Ranger 2 port [3 v] left distance cm :: #0A9E8F) < (Ranger 2 port [3 v] right distance cm :: #0A9E8F)> then
      left wheel power (40) %, right wheel power (-40) % :: motion
    else
      left wheel power (-40) %, right wheel power (40) % :: motion
    end
  else
    LED [all v] colour red (0) green (255) blue (0) :: looks
    left wheel power (40) %, right wheel power (40) % :: motion
  end
end

// Ranger 2-Way × mBlock 5  Example 5: Turn away from the nearer side  (equivalent Arduino sketch for mBot)
// Wiring: Ranger → mBot socket board → mBot port 3. Mount it on the front with both lasers facing forward.
// Does exactly what the mBlock block example does, for people who want to see "what is behind the blocks" or use the Arduino IDE.
// Libraries needed:
//   1. Makeblock (Arduino IDE Library Manager, search "Makeblock", or the copy inside the mBlock 5 install folder)
//   2. MBC_Sensors v2: the four files in src/ of the extension .mext (MBC_Sensors.h/.cpp, mbc_proto.h, mbc_ids.h),
//      put them in Documents/Arduino/libraries/MBC_Sensors/ and #include <MBC_Sensors.h> (https://mbc-pro-sensors.github.io/en/makeblock.html)
// Board: Arduino Uno (the mBot mCore is an Uno). After uploading, unplug USB and run on battery.

#include <MeMCore.h>            // mBot (mCore): motors, LED, buzzer
#include <SoftwareSerial.h>
#include <MBC_Sensors.h>        // MBC sensors v2 (the same library the mBlock extension uses)

MBCPort mbc_port3(3);           // sensor on mBot port 3
MeDCMotor motorL(9);           // left wheel (M1)
MeDCMotor motorR(10);          // right wheel (M2)
MeRGBLed rgbled(7, 2);         // on-board RGB LED (2 pixels)
MeBuzzer buzzer;               // on-board buzzer

// left / right wheel power -100~100 (positive = forward): the mBot left wheel is mounted mirrored, so M1 gets the negative value; % becomes PWM 0~255
void wheels(int l, int r) {
  l = constrain(l, -100, 100); r = constrain(r, -100, 100);
  motorL.run(-l * 255 / 100);
  motorR.run(r * 255 / 100);
}

void setup() {   // everything runs inside setup(), just like the program mBlock generates
  mbc_port3.begin();
  delay(1000);   // Wait 1 s for the sensor to boot
  while (1) {   // Repeat forever
    if ((mbcRead(mbc_port3, 0x03) < 20)) {   // If the nearer distance is less than 20
      rgbled.setColor(0, 255, 0, 0); rgbled.show();   // Obstacle: red LED
      if ((mbcRead(mbc_port3, 0x01) < mbcRead(mbc_port3, 0x02))) {   // If the left distance is less than the right distance
        wheels(40, -40);   // Nearer on the left: spin right
      } else {
        wheels(-40, 40);   // Nearer on the right: spin left
      }
    } else {
      rgbled.setColor(0, 0, 255, 0); rgbled.show();   // Clear ahead: green LED
      wheels(40, 40);   // Drive straight
    }
  }
}

void loop() {}   // nothing here: the blocks above never return

Step by step

1. Wait 1 s for the sensor to boot
2. Repeat forever
   • If the nearer distance is less than 20
     • Obstacle: red LED
     • If the left distance is less than the right distance
       • Nearer on the left: spin right
       • otherwise:
         • Nearer on the right: spin left
     • otherwise:
       • Clear ahead: green LED
       • Drive straight

What you should see: The robot drives straight with a green LED; at an obstacle it turns red and spins toward the more open side, then drives on once the way is clear.

FAQ

• Stuck spinning in a corner? → When both sides are close it keeps flipping. Add "if the nearer distance is below 8, reverse for 0.5 s first".
• The robot turns the wrong way and gets worse? → Swap the "+" and "−" (or swap the left and right wheel powers). The mBot ships with the left wheel on M1 and the right on M2; check your own wiring.
• Nothing ahead but the value is not 120? → The laser sees the floor or table: mount it higher or tilt it slightly up. Anything beyond 120 cm reads 120.
• Nothing happens, or the value stays at -32768? → Wrong port (every example on this page uses port 3), socket board not seated, or the sensor is not the Makeblock edition. Check with the "MBC common → connected?" block first; "protocol version" must read 2 for the new firmware (old firmware needs extension v1).
• Upload fails, or the blocks are blank? → Make sure the switch at the bottom right is in "Upload" mode, extension v2 has been dropped into mBlock, and the USB cable goes to the mBot board.

Next steps

• All Ranger blocks and the usable ports per board: Makeblock extension; this product's block table: Ranger 2-Way × mBlock 5
• The same ideas on LEGO: EV3 beginner examples
• Arduino straight to the sensor (I2C edition, no mBot): Arduino examples

More questions

• Blocks keep returning 0? Check the port in the block matches the real port and that the program was uploaded to the board.
• Does the old extension still work? Sensors shipped before 2026-10 use the legacy v1.0.0 extension; old and new blocks are not compatible.

Still stuck? Contact us with your software and a screenshot of the program.

Downloads

• MBC_Pro_Sensors_mBlock5_v2.2.0_import.mext
• MBC_Pro_Sensors_mBlock5_v2.1.0_import.mext
• MBC_Pro_Sensors_mBlock5_v2.0.0_import.mext
• MBC_Pro_Sensors_mBlock5_v1.0.0.mext (legacy, units shipped before 2026-10)
• Download centre (libraries, firmware, catalogue for every product)

Sources

• Host and software list：_build/guides.json
• Values and commands：_build/protocol/tof2.json (single source of truth)
• Setup：_build/guides/software/mblock-mblock5.en.md、_build/guides/product/tof2/mblock-mblock5.en.md
• Examples：sensors/tof2/mblock-examples.md