Wireless Telemetry Platform
A low-level embedded telemetry platform designed to continuously collect, timestamp, and log nearby Wi-Fi and Bluetooth activity.
The platform collects multiple telemetry sources concurrently, including GNSS position and timing data, Wi-Fi and Bluetooth scan results, and system power measurements.
Telemetry is timestamped, passed through bounded FreeRTOS queues, and written to an external microSD card. The system is designed for continuous operation with predictable memory usage and mechanisms for detecting data loss, queue saturation, and peripheral failures.
The firmware is developed in C using ESP-IDF and FreeRTOS on an ESP32-S3-WROOM development board.
- GNSS acquisition over UART with PPS-based timing
- Wi-Fi and Bluetooth Low Energy scanning
- INA226 power and current monitoring over I²C
- External microSD logging over SPI using a binary log format with CRC validation
- Concurrent FreeRTOS tasks for acquisition, processing, and storage
- Bounded queues and fixed-size buffers for predictable memory usage
Custom PCB
The firmware was prototyped on the development board. The platform is now migrating to a custom 30 mm square four-layer Altium PCB integrating the GNSS receiver (UART, PPS), microSD (SPI), and INA226 power monitor (I²C) in a compact standalone design.
Migrating the Wi-Fi and Bluetooth scanning firmware from FreeRTOS to Zephyr is in progress.
Coming soon.