In November 2017, I started writing my master thesis in the Computer Engineering Group at ETH Zürich. My thesis - officially titled "Event-based Geophone Platform with Co-detection" - is about developing a new, state-of-the-art networked sensor platform focusing on sensing micro-seismic activities to provide early warnings for natural hazard mitigation. Beside extensive research and collaboration with the Department of Geography at University of Zürich, my work included advanced hardware design from scratch and embedded software development.
After developing the first prototypes, initial field experiments were conducted which showed remarkably great results. Consequently, after finalizing every detail, the device went into production state, and currently 50 pieces were manufactured. I am extremely proud that a device which I developed and built from scratch within just 6 months were manufactured in those numbers and being deployed and used this summer in the Swiss mountains.
In May 2018, the geophone platform was featured on SRF Einstein (Swiss TV show). The part of the episode, titled "Forschung extrem: Datensammeln im Permafrost" introduces the geophone platform that I've developed alongside with the wireless sensor network deployed and operated in the Swiss mountains.
Logging to SD card with FAT32 and exFAT file system support
Ultra-low power, always-on triggering
Dual-side (positive and negative) triggering
High dynamic range, high precision triggering with hysteresis
Independent positive and negative thresholds
Switchable, dual-stage signal amplification for maximum efficiency and dynamic range
Remotely configurable threshold values and amplification stage settings
26uA total triggering consumption with single-stage amplification at 3.0V
46uA total triggering consumption with dual-stage amplification at 3.0V
High-precision 140dB SNR 24-bit ADC with integrated PGA
Battery-operated with battery voltage monitoring
USB and external power supply support
Inertial measurement unit with triggering capabilities
Temperature & humidity sensing
Metal enclosure with IP67 rating and custom-designed mounting plate
Custom, 3D-printed geophone clamp
Major software features:
FreeRTOS Real-Time Operating System
Self-customized RTOS kernel for ultra-low power consumption
High precision (sub-millisecond) time synchronization mechanism
Ultra-fast wakeup and sampling-launch: < 3ms
Logging to SD card with FAT32 and exFAT support
Configuration parameters stored on SD card
Remote on-the-fly re-configuration
Robust, fail-safe software design
Custom bootloader for firmware updates
Support for OTA (over-the-air) firmware update
Self-test and self-monitoring features
Detailed hardware-testing feature for production: manufacture, flash, connect to PC via USB and immediately see results of hardware-test to quickly identify possible manufacturing and/or component issues
Advanced RTOS tracing support for debugging
USB device support:
USB DFU (Device Firmware Upgrade) support: if bootloader needs to be upgraded
USB MSC (Mass Storage Class) support: SD card can be mounted directly to PC, without ejecting it from the device
USB CDC (Communication Device Class) support: for serial communication and command-line interface
Please note that the file size of full report is approximately 19MB, thus it may take some time to download.
The prototype PCBs were manufactured with traditional green solder mask, but the production PCBs have matte black solder mask - which looks great with the electroless nickel immersion gold (ENIG) finish.