Developers & API

Build on Motion Intelligence โ€” Faster, Cleaner, In Control

QSense is a professional IMU motion platform designed for developers, researchers and product teams who need reliable, real-time human motion data in real-world conditions.

Go from idea to instrumented test in minutes. Stream, visualize and record high-fidelity motion data without fighting toolchains, infrastructure or closed ecosystems. Prototype faster. Validate earlier. Build with confidence.

Whether you are developing XR applications, rehabilitation tools, sports analytics, industrial pilots or new wearable products โ€” QSense gives you the motion layer you can trust.

Watch: QSense Motion Platform Introduction

From Sensor to Dashboard: Building Motion-Driven Products with QSense Motion

A practical pipeline guide for researchers, entrepreneurs and app developers. Learn how to move from first measurement to a validated dashboard product โ€” including the four development stages, three algorithm engagement levels, four dashboard build options, and reference architectures for sports, rehabilitation, defense, industry and XR.

  • The four-stage development pipeline: measurement โ†’ algorithm โ†’ validation โ†’ dashboard
  • How to scope algorithm work: client-led, joint, or QSense-owned
  • Four ways to build the dashboard layer โ€” from in-house to fully delivered
  • Multi-sensor combinations: motion + ECG, EMG, force plates, instrumented objects
Download the white paper (PDF)


Why Developers Choose QSense

Rapid Real-World Prototyping

Deploy a single sensor or a full-body setup in minutes. Live streaming, 3D visualization and recording are available out of the box, so you can focus on validating concepts instead of building plumbing.

Flexible Data Outputs โ€” Your Pipeline, Your Choice

Configure sensor outputs to match your architecture:

No black boxes. No locked dashboards. Full control over your data.

Real-Time Performance for Interactive Applications


QSense is designed for closed-loop use cases where latency and timing matter:

Unity-ready examples and clear APIs make integration straightforward.

Ultra-Precise Time Synchronization

Frame-accurate alignment across sensors with:

This is what enables reliable biomechanics, phase detection and event-based feedback.

Open APIs. Transparent Architecture.

QSense is built as an open motion platform.

Without being locked into our software.

Integrate QSense Sensors into Your Custom Applications

The QSense Developerโ€™s Guide provides developers with everything they need to integrate QSense IMU motion sensors and the wireless BLE dongle into custom applications. This includes an overview of interfaces, APIs, and system-level considerations to ensure reliable motion tracking and time-synchronized data collection.

QSense provides ready-to-use C#/.NET APIs for Windows, Android, iOS (beta), and Unity. These libraries allow developers to:

  • Access sensor data and device memory through the Core Interface.
  • Control multiple sensors via a single serial channel using the dongleโ€™s Serial Interface.
  • Stream synchronized motion data for real-time or logged applications.

To jump-start development, QSense offers:

  • Code examples on GitHub for sensor and dongle integration.
  • Sample implementations demonstrating BLE communication, data logging, and time synchronization.

For multi-sensor setups, the guide covers performance tuning, BLE bandwidth optimization, and IMU calibration procedures to achieve optimal accuracy in real-world scenarios.

motion sensing API

Supported Interfaces

QSense supports multiple communication paths:

  • Direct BLE 5.2 communication with sensors
  • High-performance QSense Wireless BLE Dongle for stable multi-sensor streaming
  • Serial Interface for controlling multiple sensors through one channel

This allows you to choose the architecture that best fits your product or research setup.

motion sensing API

APIs

The following APIs are currently available for C#-based solutions:

  • QSenseDotNet Dynamic Link Library (DLL): Implements the interface for communicating with and controlling QSense sensors. This DLL does not handle BLE communication. Integration with BLE requires custom implementation or a third-party library.
  • QSenseDotNet.Dongle DLL: Extends the QSenseDotNet DLL by implementing the interface for the QSense wireless BLE dongle. This library is applicable only when using the QSense wireless BLE dongle and manages serial communication in this context.

Both DLLs target .Net Standard 2.1 framework. Due to this, they support applications targeting, among others:

  • Windows 10+, Android 8+, iOS 16+
  • .Net 5+
  • Unity 2021.2

See full version support at the official Microsoft website.

Interfaces

Direct wireless communication over BLE5.2 with the QSense motion sensor via the sensor interface. The Core Interface of the QSense sensor enables direct access to device memory for essential configuration and data retrieval.

The Serial Interface of the QSense dongle facilitates control of the dongle and provides access to the Core Interface of multiple sensors through a single serial communication channel. Interface documentation is available upon request.

The QSense interface uses BLE 5.2 with support for Data Length Extension (DLE). The API protocol makes use of the Nordic UART Service (NUS) and is defined on top of this UART interface.
The advertisement packet send by the sensor has the possibility to include a customizable name in the manufacturer specific data. The memory map uses 2 memory locations: control memory and stream memory.

Besides stream data the developer has a number of controls available:

  • Identification & versioning
  • Set device name (visible in the advertisement package)
  • Battery level percentage
  • Motion level: to identify is the sensor is tapped or moving
  • Parameters related to magnetic field mapping
  • Quality parameters
  • Gyroscope and accelerometer sensitivity
  • Set data mode: mixed, raw or quaternion
  • Sample rate, data buffer, connection interval
  • Set animation & color of the LEDs on the sensor

From Sensor to Dashboard: Building Motion-Driven Products with QSense Motion

A practical pipeline guide for researchers, entrepreneurs and app developers. Learn how to move from first measurement to a validated dashboard product โ€” including the four development stages, three algorithm engagement levels, four dashboard build options, and reference architectures for sports, rehabilitation, defense, industry and XR.

  • The four-stage development pipeline: measurement โ†’ algorithm โ†’ validation โ†’ dashboard
  • How to scope algorithm work: client-led, joint, or QSense-owned
  • Four ways to build the dashboard layer โ€” from in-house to fully delivered
  • Multi-sensor combinations: motion + ECG, EMG, force plates, instrumented objects
Download the white paper (PDF)

Example Projects & Code

We provide a public GitHub repository with examples for:

  • sensor interfaces
  • dongle communication
  • streaming & logging
  • Python integration
  • C# examples

โ†’ View QSense Examples on GitHub

Designed for Product Teams, Not Just Demos

QSense is not a toy SDK. It is a platform designed to scale from:

  • proof-of-concept
  • to pilot
  • to product
  • to volume production

We support:

  • OEM embedding
  • custom enclosures and PCB variants
  • algorithm development
  • validation & certification pathways
  • EVT / DVT / PVT support

You stay in control of your roadmap. We support you technically.

Performance & System Scaling Guidelines

When integrating QSense into multi-sensor or high-performance applications, understanding system behaviour at scale is essential. QSense is designed to scale from single-sensor prototypes to complex, time-synchronised multi-sensor systems. This section provides practical guidance on performance, throughput, and configuration to help you design reliable, high-quality solutions.

We believe developers should understand how the system behaves under different loads โ€“ not discover it through trial and error.

Multi-Sensor Performance

QSense supports flexible multi-sensor configurations. Performance depends on:

  • number of connected sensors
  • selected sample rate
  • data mode (raw, quaternion, mixed)
  • whether TimeSync mode is enabled
  • BLE connection interval and host platform capabilities

As a general guideline:

  • 1โ€“2 sensors: up to 400 Hz
  • 3โ€“6 sensors: up to 200 Hz
  • 7โ€“12 sensors: up to 100 Hz

This enables high-resolution motion capture while maintaining stable wireless performance.

Tip: for optimal throughput, the BLE connection interval is typically set to number of sensors ร— 7.5 ms.

Time Synchronization vs. Latency Trade-Off

QSense supports two operating modes:

TimeSync Mode โ€“ maximum precision

  • All sensors share a common clock
  • Continuous wireless re-synchronisation
  • Typical inter-sensor accuracy: < 60 ยตs (max < 150 ยตs)
  • Minimum connection interval: 15 ms
  • Ideal for:
    • biomechanics
    • gait analysis
    • multi-modal fusion (EMG, force plates, video)
    • research-grade analysis

Low Latency Mode โ€“ fastest response

  • Each sensor timestamps locally
  • No runtime re-synchronisation
  • Drift โ‰ค 2 ms per minute
  • Minimum latency: 7.5 ms
  • Ideal for:
    • XR interaction
    • real-time feedback
    • gaming & exergaming
    • closed-loop control

This gives you explicit control over the precision โ†” responsiveness trade-off.

BLE Throughput & Platform Considerations

Wireless BLE performance is influenced by:

  • operating system constraints (Windows, Android, iOS)
  • BLE stack implementation
  • number of simultaneous connections
  • minimum supported connection interval

QSense is tested and validated on:

  • Windows 10/11
  • Android 8+
  • iOS 16+
  • Linux & macOS (via dongle interface)

For maximum stability and throughput in multi-sensor setups, we recommend using the QSense Wireless BLE Dongle, which is optimised for high-rate, multi-device communication.

IMU Calibration & Environment Effects

For best accuracy:

  • Magnetometer calibration should be repeated when:
    • environment changes
    • metal objects or electronics are nearby
  • Gyroscope bias compensation is typically needed only:
    • after full device reset
    • after large temperature changes

This ensures consistent orientation quality and minimal drift.

Designing for Reliability at Scale

When designing larger systems, consider:

  • sensor placement and mechanical coupling
  • battery life vs. sample rate trade-offs
  • data volume and storage strategy
  • real-time vs. offline processing requirements

QSense is designed to support:

  • research pipelines
  • embedded products
  • long-term monitoring
  • field-based capture
  • OEM deployments

without changing platform or architecture.

We Help You Tune It

System scaling is not guesswork. We actively support teams with:

  • configuration advice
  • performance tuning
  • throughput optimisation
  • architecture review
  • validation and testing

So you can focus on building your application โ€“ not fighting the underlying system.

When You Need More Than an SDK

We also provide hands-on integration support:

  • system architecture review
  • performance tuning
  • multi-sensor synchronization design
  • BLE optimization
  • custom firmware or features
  • OEM development support

Our team has deep experience in wireless systems, embedded platforms and wearable products โ€” and we bring that into your project.

Ready to Build?

Whether you are:

  • prototyping a new idea
  • integrating motion into your product
  • or building a commercial solution

QSense gives you the motion intelligence layer to build on.

Contact our team to discuss your project
QSENSE-MOTION-WEARABLE-MOTION-SENSOR

Whether you are optimizing performance, improving recovery, enhancing safety or developing a motion-driven product, QSense provides the foundation to turn human movement into actionable insight.

We work with performance teams, clinicians, engineers and technology partners in sports, health, industry and defense to build motion intelligence solutions that perform in real-world conditions.

Letโ€™s discuss your application and explore how QSense can support your goals.

qsense frontside

Questions?

Have questions about motion intelligence, system integration or application possibilities? Our team is here to explore your use case and advise on the best approach.

Blog

Latest from our blog

Machine Learning Gait Analysis: How AI and Fewer IMU Sensors Are Reshaping Motion Capture

Machine Learning Gait Analysis: How AI and Fewer IMU Sensors Are Reshaping Motion Capture

1. Doing more with fewer sensors: ML-based fusion and sensor reduction The conventional path to better motion data was to ...
The Best IMU Sensor for Gait Analysis Research: What Actually Matters

The Best IMU Sensor for Gait Analysis Research: What Actually Matters

Why IMUs took over gait analysis Optical motion capture remains the historical gold standard, but it is expensive, fixed to ...

From IMU to insight: a practical pipeline for building motion-driven products

The four stages, in plain language Stages 1 and 2 together are the technical heart of your product. Stage 3 ...
QSENSE-MOTION-WEARABLE-MOTION-SENSOR

QSense is a motion intelligence platform for performance-critical applications in sports, health, industry and defense. We enable organizations to measure, analyze and act on human motion where accuracy, timing and reliability matter.

QSense is developed by 2M Engineering.

Contact

2M Engineering

John F Kennedylaan 3

5555XC Valkenswaard

The Netherlands

en_USEnglish