ESPARGOS: ESP32-based WiFi Sensing Array
ESPARGOS is a specialized hardware device designed for WiFi sensing applications, built around the ESP32 microcontroller platform. This phase-coherent antenna array enables developers and researchers to capture and analyze WiFi Channel State Information (CSI) in real-time, opening up possibilities for indoor localization, motion detection, and various sensing applications without requiring modifications to existing WiFi devices.
Key Features
WiFi Channel State Information (CSI) Capture The device extracts CSI from WiFi pilot symbols in real-time, providing detailed information about signal phase shifts and attenuation across OFDM subcarriers. With support for channel bonding up to 40 MHz bandwidth, ESPARGOS can capture comprehensive channel characteristics for advanced signal analysis.
2×4 Antenna Array Configuration ESPARGOS features an 8-antenna array arranged in a 2×4 configuration, enabling sophisticated spatial signal processing techniques like angle-of-arrival estimation using algorithms such as MUSIC. Multiple units can be combined to create larger phase-synchronous arrays for enhanced sensing capabilities.
Power over Ethernet Integration The device simplifies deployment by combining data, power, and control through a single Ethernet connection. Built-in Power over Ethernet (PoE) support means no separate power cables are needed, while the integrated web interface allows for easy configuration and monitoring.
Python Software Ecosystem ESPARGOS comes with pyespargos, a comprehensive Python library that handles device control and real-time data streaming. The library includes multiple demo applications covering spatial spectrum visualization, time-domain analysis, localization algorithms, and even camera overlay applications.
Applications
ESPARGOS enables passive indoor localization of smartphones, robots, and IoT devices without requiring any software changes on the target devices. The system can perform triangulation in line-of-sight scenarios and uses advanced techniques like Channel Charting for non-line-of-sight localization. This makes it valuable for indoor positioning systems, occupancy detection, gesture recognition, and environmental monitoring.
Development Status
Currently developed at the University of Stuttgart’s Institute of Telecommunications, ESPARGOS is transitioning from research prototype to commercial product. While the hardware design remains proprietary, the Python software library and demo applications are available as open-source software. Commercial manufacturing is planned with PCB redesigns for mass production and certification.