Indoor tracking is one of the trickiest problems in IoT, GPS doesn’t work well inside buildings, and Wi-Fi or Bluetooth can only estimate positions within a few meters. That’s where Ultra-Wideband (UWB) stands out. Using an ESP32 and Qorvo DWM3000 module, you can build a UWB-based positioning system that locates devices with up to 10 cm precision. In this post, we’ll break down how it works, how to set it up, and how you can visualize real-time tracking using Python.
Lets see how this UWB Indoor Positioning System using ESP32 works
Why GPS Falls Short Indoors
GPS works great outdoors but struggles indoors because:
- Satellite signals weaken through walls and roofs.
- Multipath reflections cause inaccurate readings.
- Even in open indoor spaces, accuracy is usually 5–10 meters.
If you only need coarse outdoor tracking, check out GeoLinker GPS Tracking Platform , CircuitDigest’s free, open-source GPS project platform.
But for precise indoor tracking, you’ll want to stick around for this UWB setup.
What Makes UWB Ideal for Indoor Positioning?
Here’s a quick comparison of popular indoor positioning technologies:
| Technology | Accuracy | Range | Best Use Case |
|---|---|---|---|
| UWB | 10 cm | Up to 200 m | RTLS, Asset Tracking |
| Bluetooth | 1–3 m | Up to 100 m | Proximity Detection |
| Wi-Fi | 5–15 m | Up to 50 m | Zone-Level Tracking |
| GPS | 5–10 m | Global | Outdoor Tracking Only |
UWB’s edge is in its time-of-flight (ToF) precision - measuring distances based on how long it takes for a pulse to travel, not just signal strength.
Meet the Qorvo DWM3000 Module
The Qorvo DWM3000 is a fully integrated UWB transceiver module built around the DW3110 IC.
It’s designed for high-accuracy ranging and tracking and supports the IEEE 802.15.4z standard, ensuring interoperability with the wider UWB ecosystem.
Key Specs:
- Operating Bands: Channel 5 (6.5 GHz), Channel 9 (8 GHz)
- Accuracy: Up to 10 cm
- Data Rate: 850 kbps or 6.8 Mbps
- Interface: SPI (up to 38 MHz)
- Security: IEEE 802.15.4z STS (anti-spoofing)
- Size: 24 × 16 mm compact footprint
Best part? It’s plug-and-play - no deep RF design expertise required.
How a UWB Positioning System Works (Step-by-Step)
Here’s the basic flow of how the ESP32 + DWM3000 system determines position:
- Anchor Setup: Place at least three anchors at fixed, known positions in your space.
- Tag Initialization: The mobile tag (attached to the item you’re tracking) communicates with the anchors.
- Two-Way Ranging (TWR): Each anchor and tag exchange UWB pulses to measure distance.
- Trilateration: Using distances from three or more anchors, the system computes the exact (x, y) location.
- Visualization: Data is sent to a PC or cloud app for real-time tracking.
Components You’ll Need
| Component | Quantity | Description |
|---|---|---|
| Qorvo DWM3000 Module | 4 | 1 Tag + 3 Anchors |
| ESP32-WROOM Board | 4 | One for each UWB module |
| Breadboard / PCB | 4 | For wiring and mounting |
| 5V Power Source | 4 | Stable USB or power bank |
| Micro-USB Cables | 4 | Programming & power |
How Two-Way Ranging (TWR) Works
UWB modules measure distance using Double-Sided Two-Way Ranging (DS-TWR).
Here’s what happens during one measurement cycle:
- Poll: Tag sends a “Poll” message and records the transmit time (T1).
- Response: Anchor receives it at (T2) and sends a “Response” after a known delay (T3).
- Final: Tag receives it at (T4) and calculates time-of-flight (ToF).
For more code and indepth tutorial : Build an UWB Indoor Positioning System using ESP32 and Qorvo DWM3000
Key Takeaways
- UWB (Ultra-Wideband) provides 10 cm accuracy indoors - far beyond GPS or Wi-Fi.
- Qorvo’s DWM3000 module is a developer-friendly entry into UWB projects.
- The ESP32 handles communication, data transfer, and Wi-Fi visualization with ease.
- You can scale this setup to multi-tag tracking for warehouses, robotics, or smart factories.
- The Python-based demo helps visualize real-time UWB localization for practical testing.
What’s Next?
You can extend this project into:
- A multi-tag RTLS system for warehouse automation.
- Wearable trackers for workers or tools.
- UWB-based AR/VR spatial awareness.
Building with UWB might sound advanced, but with modules like the DWM3000 and an ESP32, it’s now more accessible than ever for makers and engineers.
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