Data Types

Namespace: RpLidar.NET.Entities

All measurement and response data types returned by the library.

Table of Contents

1. LidarPoint
   1. Properties
   2. Example
2. LidarPointGroup
   1. Constructor
   2. Properties
   3. Indexers
   4. Methods
      1. Add(LidarPoint point)
      2. AddRange(IEnumerable<LidarPoint> points)
      3. GetPoints()
      4. Filter()
      5. Compare(LidarPointGroup group)
3. LidarPointGroupItem
   1. Properties & Fields
4. InfoDataResponse
   1. Properties
5. RpHealthResponse
   1. Properties
6. ResponseDescriptor
7. IDataResponse
8. See Also

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LidarPoint

public class LidarPoint

Represents a single distance measurement at a given angle. This is the fundamental unit of scan data you receive in LidarPointScanEvent.

Properties

Property	Type	Description
Angle	float	Measurement angle in degrees (0–360).
Distance	float	Distance in millimetres. 0 means the sensor could not measure at this angle.
Quality	ushort	Signal quality (higher = better). Typical range 0–63.
StartFlag	bool	true for the first point of a new 360° revolution.
Flag	int	Raw internal flag byte from the protocol packet.
IsValid	bool	Computed: true when Distance > 0. Always check this before using Distance.

Example

lidar.LidarPointScanEvent += points =>
{
    foreach (var pt in points)
    {
        if (!pt.IsValid) continue;             // skip zero-distance readings
        if (pt.Distance > 5000) continue;      // skip far readings

        Console.WriteLine($"{pt.Angle:F1}° → {pt.Distance:F0} mm (quality {pt.Quality})");
    }
};

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LidarPointGroup

public sealed class LidarPointGroup : IEnumerable<LidarPointGroupItem>

An angle-indexed map of scan points at 0.1° resolution (3 600 possible slots). Received via LidarPointGroupScanEvent. Useful for map-building and inter-sweep comparison.

Constructor

public LidarPointGroup(double x, double y)

Parameter	Type	Description
x	double	X coordinate of the sensor origin in your world space.
y	double	Y coordinate of the sensor origin in your world space.

Properties

Property	Type	Description
X	double	X position of the sensor.
Y	double	Y position of the sensor.
Settings	ILidarSettings	The settings applied when this group was built.
Count	int	Number of occupied angle slots.
Items	IEnumerable<LidarPointGroupItem>	All occupied slots.

Indexers

public LidarPointGroupItem this[float angle]   // angle in degrees (e.g. 90.5f)
public LidarPointGroupItem this[int angle]     // integer degrees (e.g. 90)

Returns the point group item nearest to the requested angle, or null if no measurement exists.

Methods

Add(LidarPoint point)

Adds a single LidarPoint to the group.

AddRange(IEnumerable<LidarPoint> points)

Adds multiple points at once.

GetPoints()

public List<LidarPoint> GetPoints()

Returns all stored points as a flat list.

Filter()

public List<LidarPoint> Filter()

Returns a noise-filtered list of points. Removes isolated outliers.

Compare(LidarPointGroup group)

public double Compare(LidarPointGroup group)

Compares this group with another and returns a similarity score from 0.0 (completely different) to 1.0 (identical). Useful for change/motion detection.

double similarity = sweep1.Compare(sweep2);
if (similarity < 0.85)
    Console.WriteLine("Significant change detected!");

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LidarPointGroupItem

public sealed class LidarPointGroupItem

One slot in a LidarPointGroup, representing the best measurement for a 0.1° angle bin.

Properties & Fields

Member	Type	Description
Angle	int	Angle key (degrees × 10, e.g. 905 = 90.5°).
OriginalAngle	float	The original float angle from the sensor.
Distance	float	Distance in millimetres.
Count	int	Number of raw points that contributed to this slot.
Cathetus	double?	Optional computed perpendicular component.
CanIgnore	bool	Marks this item as a noise outlier (set by Filter()).

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InfoDataResponse

public class InfoDataResponse : IDataResponse

Returned by device.SendRequest(Command.GetInfo).

Properties

Property	Type	Description
Type	RpDataType	Always RpDataType.GetInfo.
ModelId	string	Sensor model identifier (e.g. "A1M8").
FirmwareVersion	string	Firmware version string.
HardwareVersion	string	Hardware revision string.
SerialNumber	string	Unique device serial number.

var info = device.SendRequest(Command.GetInfo) as InfoDataResponse;
Console.WriteLine($"Model: {info?.ModelId}, FW: {info?.FirmwareVersion}");

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RpHealthResponse

public class RpHealthResponse : IDataResponse

Returned by device.SendRequest(Command.GetHealth).

Properties

Property	Type	Description
Type	RpDataType	Always RpDataType.GetHealth.
Status	int	0 = Good, 1 = Warning, 2 = Error.
ErrorCode	int	Non-zero when Status is Warning or Error.

var health = device.SendRequest(Command.GetHealth) as RpHealthResponse;
if (health?.Status != 0)
    Console.WriteLine($"Sensor issue! Status={health.Status} Code={health.ErrorCode}");

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ResponseDescriptor

public class ResponseDescriptor

Low-level protocol response descriptor (7-byte header). Typically used internally.

Property	Type	Description
ResponseLength	int	Expected payload length in bytes.
SendMode	SendMode	Single or multi-response.
RpDataType	RpDataType	The data type of the following payload.

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IDataResponse

public interface IDataResponse

Base interface for all response objects returned by SendRequest.

Member	Type	Description
Type	RpDataType	Identifies the concrete response type.

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See Also

• Enumerations — ScanMode, Command, RpDataType, SendMode
• RpLidarSerialDevice — source of all these responses