Documentation

Onboarding

Budget Planning Common Beginner Mistakes First Boot Learning Path Legal Basics for Beginners How the Beacon Saves Lives Understanding the Modes in One Page Morse Code for Beginners Parts Overview Reading the OLED Screens Radio Basics for Complete Beginners Safety First Tools You Need Using the BOM Builder Using the Interactive Demo Welcome to the Wiki

Getting Started

Bench Power Bench Testing Basics Boot Process Build Configurations Choosing a Build Configuration Static Safety and ESD ESP32 Troubleshooting Checklist Frequently Asked Questions First Transmission First Use Project Overview Quick Start Guide Shopping List Sourcing Parts System Architecture Troubleshooting Version Selection Workspace Setup

Power & Battery

Hardware & Components

Build & Assembly

3D Printing the Enclosure Assembly Guide Assembly Sequence Audio Jack Wiring Audio Troubleshooting Bench Checklist Breadboard Prototyping Building Your Own Case Button Actions in CONFIG Mode Button System Details Button Troubleshooting Case Cutouts Guide Case Materials Circuit Description Connector Types Datasheet Reading Dummy Load and Bench Testing Electrical Specifications Enclosure Options Flux and Solder Glue and Adhesives GPIO Pin Map Reference GPIO Pin Mapping Ground Planes and Counterpoises Ohm's Law Resistors, Capacitors and Passives Schematic Reading Screw and Fastener Guide Soldering Basics Soldering Iron Guide Two-Beacon Bench Test Waterproof Build Waterproofing and Enclosure Sealing Wire and Connectors Wire Gauge Guide Wiring and Connectors Wiring Order and Routing Wiring Quick Reference

Radio & RF Design

Antenna Cable and Connectors Antenna Design Antenna Efficiency Antenna Height Matters Antenna Length Reference Antenna Mounting Antenna Quick Select Antenna Testing and Tuning Antenna Theory Primer Antenna Troubleshooting Antenna Design and Selection Coax Loss Tables dBm Explained Foliage Loss The Fresnel Zone GPS Antenna Placement Half Wave Dipole Helical Antenna Homebrew Antenna Interference Sources at 433 MHz Line of Sight and Terrain LoRa vs FSK Modulation in the Beacon Morse Timing and Audio Sync Mountain Effects on Radio Propagation and Range Propagation Modes Quarter Wave Antenna Radio Quick Start Radio Shadow Receiver Testing RF Basics for the Beacon RF Design & Link Budget RF Exposure Safety RF Interference and Noise RSSI Explained Sensitivity vs Selectivity SWR Explained SX1262 Datasheet Notes SX1262 Frequency Ranges SX1262 Registers Transmitter Testing Tropospheric Ducting Troubleshooting RF Issues Urban RF Environment VSWR Measurement

Frequencies & Regulations

Firmware & Software

Arduino CLI Guide Boot Loop Troubleshooting Boot Screens and Errors Changelog Code Style Guide Config Backup Config Dashboard Why the Dashboard Uses System Fonts CONFIG Payload Format Configuration Reference Dashboard HTTP API Dashboard Rendering ESP32 ADC Guide ESP32 Flash Security ESP32 Interrupts Guide ESP32 RTC Notes ESP32 Serial Debug Output ESP32 Timers Guide ESP32 WiFi Hardware esptool Guide Extending the Serial Protocol Factory Reset and Recovery Firmware CW Decoder Firmware System Monitoring Frequency Setting over Serial The Button System in Firmware How Firmware Loads Configuration Firmware Deep Sleep Firmware Error Codes Firmware GPS Handling The Firmware Main Loop Firmware NVS Keys Firmware Overview The Payload Builder Firmware RSSI Measurement The Scan Cycle in Detail Firmware Scan Engine The Firmware State Machine Firmware Tone Generation The TX Cycle in Detail Firmware TX Scheduler Upgrading to v5.5 Firmware Update in the Field Firmware Wake Sources The Watchdog Benchmark Demo Mode Flash Troubleshooting No Boot? Troubleshooting No Display? Troubleshooting NVS Configuration Store PlatformIO Guide RTC RAM State Battery Logging over Serial Serial Bridge Guide Serial Command Automation Serial Command Protocol Serial Debug System Serial Monitor Guide Software Build Process Unit Testing the Firmware Upload and Monitor What's New in v5.5 What's New in v6.0 WiFi and Security WiFi Configuration Portal WiFi Troubleshooting

USB & Connectivity

Android OTG Guide Bridge Automation Bridge Security Bridge Troubleshooting Bridge TUI CH340 Driver Install CP210x Driver Install Report Position Page USB-Serial Adapter Troubleshooting Serial Port Detection Termux: Serial Bridge on Android USB Cable Types USB Connection Guide USB Power vs Data Web Serial: Browser-Only Option

GPS & Navigation

Morse & Communication

Modes & Operation

Glossary of Modes and Settings BEACON Mode CONFIG Mode EMERGENCY Mode LISTEN Mode SEARCH Mode Mode Screens and Icons Operating Modes Scan Engine Details

Field Operations & Rescue

Avalanche Rescue Operation Avalanche Safety Basics Beacon Care Seasonal Beacon Log Template Cleaning and Inspection Crevasse Rescue Distance Estimation from RSSI Emergency Cheat Sheet Emergency Communications Plan Emergency Kit Emergency Response Minute by Minute Emergency Response Scenarios Field Checklist Field Deployment Guide Field Maintenance and Storage Field Repair Kit Field Signals Cheat Sheet First Aid Kit Ground to Air Signals Group Communication Plan Hiking Safety Homing Technique Homing with the Serial Bridge Hypothermia Recognition Incident Command Long Term Storage Mirror Signaling Mission Debrief One Bridge, Several Beacons Night Operations Off-Grid Position Sharing Outdoor Testing Guide Pack Check Routine Position Logging Workflow Pre-Trip Checklist Repeater Position Reporting Ridge Crossing Technique Safety Guidelines Safety Quick Rules Search Patterns and Procedure Signal Strength Mapping Signal Triangulation Signaling Techniques Snow and Signal Behavior Snow Shelter Signaling Snow Signal Math Storm Operations Terrain Reading for Radio Trip Planning Water Damage Recovery Weather Planning Whistle Signals Winter Operations Winter Pack

Building Effectively

Effective Build Strategy Build Quality Gates Bench Jigs and Fixtures Rework and Desoldering Build Time Planning Build Log and Tracking

Build Variants

Displayless Build Minimal Build Multi-Beacon Network Multi-Beacon Operations Multi-Beacon Frequency Planning Repeater Beacon Standard Build Configuration

Project & Reference

The Firmware State Machine

The states the firmware can be in, the transitions between them, and where each transition is triggered.

The Firmware State Machine

The beacon’s behavior is a small state machine. Mapping it out makes the firmware readable and debugging faster.

The states

CODE

BOOT → BEACON (default or NVS-saved mode)
BOOT → SEARCH   (MODE short press)
BOOT → CONFIG   (SEL held 3 s)
BOOT → FACTORY_RESET (MODE+SEL at boot 5 s)

BEACON ⇄ SEARCH   (MODE short press)
BEACON → EMERGENCY (MODE held 2 s)
SEARCH → EMERGENCY (MODE held 2 s)
CONFIG → EMERGENCY (dashboard emergency button)

EMERGENCY → BEACON (MODE held 2 s)
CONFIG → BEACON    (Save & Reboot)

Where the state lives

The current mode is stored in a global variable and mirrored in RTC RAM so it survives deep sleep.
On boot, setup() restores the mode from RTC RAM (unless a factory reset is pending).

The emergency flag

EMERGENCY is special: a persisted flag in RTC RAM marks the state even across power cycles. If the beacon is in EMERGENCY at deep sleep (it should not sleep in EMERGENCY, but a power loss can happen), it reboots back into EMERGENCY. Clearing it requires entering CONFIG and saving.

Sub-states inside BEACON

BEACON itself has phases: sleep-wait → payload-build → per-frequency TX → sleep. Each phase is a step in the handler, advanced by a timer, not by blocking delays.

Sub-states inside SEARCH

SEARCH steps: tune frequency → open RX window (dwell) → sample RSSI → classify → next frequency. The hit log and LED heartbeat update per step.

Why this design

A state machine with non-blocking steps keeps the UI responsive (OLED, buttons, battery) during TX, and makes the mid-TX abort simple: the MODE interrupt sets a flag the next step checks.

Debugging with the state machine

The serial log prints [STATE] transitions. If the beacon behaves oddly, the log shows which state it is stuck in and which transition never fired. See the serial debug pages for the full tag reference.