RpLidar.NET

A .NET library for interfacing with Slamtec RPLidar A-series LiDAR sensors over a serial connection. Tested with real hardware (A1M8). Targets netstandard2.0 — compatible with .NET 6, 7, 8, and .NET Framework 4.6.1+.

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Documentation

Full documentation is available at asheesh1996.github.io/RpLidar.NET:

• Getting Started — Installation, platform setup, usage patterns
• API Reference — Every class, method, and property documented
• Support — How to report bugs and request features

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Supported Hardware

Model	Scan Mode	Max Range
A1M8	Standard / Sensitivity	12 m
A2M8	Standard / Boost / Sensitivity	18 m
A3M1	Standard / Boost / Sensitivity	25 m

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Installation

dotnet add package RpLidar.NET

Or via the NuGet Package Manager in Visual Studio: search for RpLidar.NET.

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Quick Start

using RpLidar.NET;
using RpLidar.NET.Entities;

// Replace with your actual port:
//   Windows : "COM3"
//   Linux   : "/dev/ttyUSB0"
//   macOS   : "/dev/tty.usbserial-..."
using var lidar = new RPLidar("COM3");

lidar.LidarPointScanEvent += points =>
{
    foreach (var p in points)
        Console.WriteLine($"Angle: {p.Angle:F1}°  Distance: {p.Distance:F0} mm  Quality: {p.Quality}");
};

Console.WriteLine("Scanning — press Enter to stop.");
Console.ReadLine();

The RPLidar constructor connects, starts the motor, and begins scanning immediately. Scan data is delivered via LidarPointScanEvent approximately every 400 ms (configurable).

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Scan Modes

Mode	Enum Value	Protocol	Description
Standard	ScanMode.Standard	Scan (0x20)	Basic scan, ~2,000 samples/rev. All A-series.
Boost	ScanMode.Boost	Express Scan (0x82, mode=3)	Higher frequency. A2/A3 only.
Sensitivity	ScanMode.Sensitivity	Express Scan (0x82, mode=4)	Ultra-Capsule; highest density. Default.

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Custom Configuration

Use RpLidarSerialDevice directly for full control:

using RpLidar.NET;
using RpLidar.NET.Entities;

var settings = new LidarSettings
{
    Port                = "COM3",
    BaudRate            = 115200,
    ScanMode            = ScanMode.Sensitivity,
    Pwm                 = 660,     // Motor speed: 0 (stop) – 1023 (full)
    MaxDistance         = 25000,   // mm — consumers can filter by this
    ElapsedMilliseconds = 400,     // Scan event fires at most every 400 ms
};

using var device = new RpLidarSerialDevice(settings);
device.LidarPointScanEvent += OnScan;
device.Start();

Console.ReadLine();
device.Stop();

static void OnScan(List<LidarPoint> points)
{
    Console.WriteLine($"{points.Count} points");
}

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API Reference

RPLidar — high-level wrapper

Member	Description
RPLidar(string port, int baudrate = 115200)	Connect and start scanning.
event LidarPointScanEvent	Raised with batched scan points.
Stop()	Stop scanning and motor.
Dispose()	Stop and release all resources.

RpLidarSerialDevice — low-level device

Member	Description
Connect()	Open the serial port.
Disconnect()	Close the serial port.
StartMotor()	Enable motor at the configured PWM.
StopMotor()	Set PWM to 0 and stop motor.
StartScan()	Start Standard scan and read thread.
ForceScan()	Force scan (no motor-sync check).
ForceScanExpress()	Start Express scan (Boost or Sensitivity).
StopScan()	Stop the read thread and motor.
Start()	Connect → StopScan → pick scan mode → start.
Stop()	StopScan.
SendRequest(Command)	Send a raw protocol command.
event LidarPointScanEvent	Raw point list, fired on timer.
event LidarPointGroupScanEvent	Angle-keyed LidarPointGroup, fired on timer.

LidarPoint

Property	Type	Description
Angle	float	Heading in degrees (0 – 360).
Distance	float	Distance in millimetres.
Quality	ushort	Measurement quality (higher = better).
StartFlag	bool	true at the start of a new 360° revolution.
IsValid	bool	true when Distance > 0.

LidarPointGroup

An angle-keyed collection (0.1° resolution) built from a batch of LidarPoint values. Useful for per-angle lookups:

// Nearest obstacle directly ahead
var ahead = group[0];   // angle = 0°
if (ahead != null)
    Console.WriteLine($"Obstacle at {ahead.Distance} mm");

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Platform Notes

• Windows: Use COMn port names (e.g. COM3). The USB-UART adapter appears in Device Manager.
• Linux: Typically /dev/ttyUSB0. You may need to add your user to the dialout group:

  sudo usermod -aG dialout $USER

• macOS: /dev/tty.usbserial-* or /dev/tty.SLAB_USBtoUART.

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Building from Source

git clone https://github.com/asheesh1996/RpLidar.NET.git
cd RpLidar.NET
dotnet build

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License

MIT