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pxt-mbc-sensors

MBC Pro Sensors (line follower, laser distance, gamepad, IMU, camera) for micro:bit V1/V2 MakeCode - beta: hardware bench test in progress

MBC Pro Sensors for micro:bit

Open this page at https://contactmbcrobot.github.io/pxt-mbc-sensors/

MakeCode extension for MBC Pro Sensors on BBC micro:bit V1 and V2 (MBC I2C protocol v2, 2026-10). Product site: https://mbc-pro-sensors.github.io/ (繁體中文／English).

Product I2C address Group micro:bit page
Line follower 8-ch / 16-ch (循行者) 0x16 Line line8 · line16
Distance sensor 2-ch / 8-ch (測距者) 0x29 Distance tof2 · tof8
Gamepad receiver PS2 / PS4 (掌控者) 0x42 Gamepad ps2 · ps4
IMU / gyro (陀螺儀) 0x6A IMU imu
ESP32 camera, school / WRO edition (神攝手) 0x4C Camera esp32cam

Wiring: MBC 4-pin cable to the micro:bit edge connector, P19 = SCL, P20 = SDA, 3V and GND. Several products can share the bus as long as their addresses differ (change an address with the Device blocks). Products that draw more than the micro:bit 3V pin can supply (distance 8-ch, ESP32 products) need their own power.

Use as Extension

This repository can be added as an extension in MakeCode.

Traditional Chinese block names are included (_locales/zh-TW): switch the editor language to 繁體中文.

Blocks

Line follower

// Sweep the sensor over black and white for 5 s to calibrate (saved on the sensor)
mbc.lineCalibrate(MbcLineCalib.Auto)
basic.forever(function () {
    // 0 = line in the centre, negative = line on the left (seen from behind the robot)
    basic.showNumber(mbc.linePosition())
    // channel 1 is the leftmost channel
    if (mbc.lineChannelOnLine(1)) {
        basic.showArrow(ArrowNames.West)
    }
})
// Runs once when the robot loses the line
mbc.onLineEvent(MbcLineEvent.Lost, function () {
    basic.showIcon(IconNames.No)
})

Distance sensor

// Long-range mode: "no target" becomes 200 cm instead of 120 cm (sensor firmware 2026-10-29 or later)
mbc.tof8SetMode(MbcTofMode.LongRange)
basic.forever(function () {
    // 2-way sensor: distance of the left laser in cm
    basic.showNumber(mbc.tof2Distance(MbcTofSide.Left, MbcDistUnit.Cm))
    // 8-way sensor: nearest target in mm and its direction (-8 left ... 0 front ... +8 right)
    basic.showNumber(mbc.tof8Nearest(MbcDistUnit.Mm))
    basic.showNumber(mbc.tof8NearestDirection())
})
// Runs when anything comes closer than 10 cm to the 8-way sensor
mbc.onTof8Near(10, function () {
    basic.showIcon(IconNames.Skull)
})

Gamepad

// When ✕ is pressed: rumble and turn the light bar red (PS4 / PS5 gamepads)
mbc.onPadButton(MbcPadButton.Cross, MbcPadButtonEvent.Pressed, function () {
    mbc.padRumble(200)
    mbc.padLight(0xff0000)
})
basic.forever(function () {
    // Only read the stick while a gamepad is paired; left stick up/down is -100 ... 100
    if (mbc.padConnected()) {
        basic.showNumber(mbc.padStick(MbcPadAxis.LeftY))
    }
})

IMU

// Make the current direction 0°
mbc.imuZeroHeading()
basic.forever(function () {
    // Heading in degrees, and nose up / down angle
    basic.showNumber(mbc.imuHeading(MbcImuHeading.Fused))
    basic.showNumber(mbc.imuPitch())
})
// Runs after the robot has turned 90°
mbc.onImuTurned(90, function () {
    basic.showIcon(IconNames.Yes)
})

Camera

basic.forever(function () {
    // School edition: X position of the tracked colour blob
    if (mbc.camFound()) {
        basic.showNumber(mbc.camBlob(MbcCamBlob.X))
    }
    // WRO edition: colour code of spot 1
    basic.showNumber(mbc.camSpotColor(1))
})

Device (advanced)

// Wait up to 5 s for the line follower, then show its firmware version and kind
if (mbc.waitReady(mbc.ADDR_LINE, 5000)) {
    basic.showString(mbc.firmwareVersion(mbc.ADDR_LINE))
    basic.showNumber(mbc.deviceKind(mbc.ADDR_LINE))
}

When a sensor is not connected

If a sensor does not answer (unplugged, no power, wrong address), the blocks do not stop the program and print nothing:

0 can also be a real reading (line in the centre, hue red, object touching the sensor), so check the connection first with device at … is ready (Device, advanced): it is false when nothing answers.

basic.forever(function () {
    if (mbc.deviceReady(mbc.ADDR_LINE)) {
        basic.showNumber(mbc.linePosition())
    } else {
        // nothing answers at 0x16: check the cable and power
        basic.showIcon(IconNames.No)
    }
})

Learn more

Protocol v2 in short

Block help

Right-click any block → Help opens its page in docs/ (description, parameters, a runnable example and the product guide link).

Test

test.ts calls every block at least once.

Status: all blocks compile and run in the simulator on V1 and V2; checking each block against real sensors on V1 and V2 is in progress.

License

MIT — Shaobo Creative Robotics Company Limited (MBC Robot)

Supported targets

Metadata (used for search, rendering)