README

Overview of raspberry pi drifter setup

Summary

This documents the hardware and software used to develop an open-source, low-cost, drifting recorder for passive acoustic monitoring during vessel surveys.

Project structure

setup.md - hardware and software setup instructions
src/deploy.sh - main script that implements recording, gps-time sync, and logging
src/deploy.service - script to add to Pi that runs src/deploy.sh at startup. On the Pi it is located in /etc/systemd/system/deploy.service. See setup.md for more information.
r - various data processing utilities (for summarizing/analyzing results after deployment)

Fixes / Modifications

• Use stored clock on GPS hat at startup
• Consider adding external GPS antenna
• Switch to headless / no desktop mode to reduce power consumption
• Diagnose dropout issue
• Add external status LED
• Test localization
• Improve real-time comms
  • Wifi connectivity
    • Use dsnoops for shared mic capture. This will allow separate, simultaneous processes for recording and streaming
    • Test 20 has a lot of info on streaming with TCP and RTP, but I wasn't able to overcome dropouts with either. Next steps might be using pulseaudio utils.
  • Real-time summaries
    • Noise levels
    • Spectrograms
    • Calls / detector