vl53l0x

Overview

The vl53l0x node measures distance using the STMicroelectronics VL53L0X time-of-flight laser ranging sensor via I2C. Unlike ultrasonic sensors, it uses a VCSEL laser for fast, accurate measurements unaffected by target color or reflectivity. Ideal for liquid level sensing, object detection, and robotics.

Wiring (I2C)

Properties

Output

{
  "payload": 342,
  "distance": 342,
  "unit": "mm",
  "status": "valid",
  "timestamp": 1640000000000
}

Example: Liquid Level Sensing in Tank

Mount the sensor above a tank to measure liquid level and calculate volume remaining.

// Function node: Calculate tank level
var distance = msg.distance; // mm from sensor to liquid
var tankHeight = 500;        // Total tank depth in mm
var tankDiameter = 300;      // Tank diameter in mm

// Distance to liquid surface → liquid height
var liquidHeight = tankHeight - distance;
liquidHeight = Math.max(0, Math.min(tankHeight, liquidHeight));

// Calculate volume (cylindrical tank)
var radius = tankDiameter / 2;
var volume = Math.PI * Math.pow(radius, 2) * liquidHeight;
var volumeLiters = volume / 1000000; // mm³ to liters
var percent = (liquidHeight / tankHeight) * 100;

var status = "ok";
if (percent < 10) status = "critical";
else if (percent < 25) status = "low";

msg.payload = {
    distance: distance,
    level: liquidHeight.toFixed(0),
    percent: percent.toFixed(1),
    liters: volumeLiters.toFixed(2),
    status: status
};

return msg;

Example: Conveyor Belt Object Counter

Count objects passing on a conveyor belt by detecting distance changes.

// Function node: Object detection and counting
var distance = msg.distance;
var threshold = 200;  // Object closer than 200mm
var prevState = flow.get('objectPresent') || false;
var count = flow.get('objectCount') || 0;

var objectPresent = distance < threshold;

// Count on rising edge (object enters beam)
if (objectPresent && !prevState) {
    count++;
    flow.set('objectCount', count);
}

flow.set('objectPresent', objectPresent);

msg.payload = {
    distance: distance,
    objectPresent: objectPresent,
    count: count
};

return msg;

Use Cases