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

Circuit Description

How every bus and rail is wired: SPI, UART, DAC audio, battery divider, LEDs and buttons

Circuit Description

Overview

The Aegis-Beacon circuit is designed for simplicity and reliability. All connections use standard 0.1” pitch headers for easy assembly and debugging.

SPI Bus Configuration

VSPI (Hardware SPI) — SX1262 Radio

Signal	ESP32 GPIO	SX1262 Pin	Notes
SCK	GPIO 18	SCK	SPI clock
MISO	GPIO 19	MISO	Data from radio
MOSI	GPIO 23	MOSI	Data to radio
CS	GPIO 5	NSS	Chip select (active LOW)
RESET	GPIO 14	RESET	Active LOW reset
BUSY	GPIO 21	BUSY	MANDATORY — RadioLib polls

Warning

The BUSY pin is not optional. If GPIO 21 is not wired to BUSY, the firmware will hang on the first radio call.

Software SPI — SSD1309 OLED

Signal	ESP32 GPIO	OLED Pin	Notes
SCK	GPIO 15	D0	SPI clock
SDA	GPIO 13	D1	SPI data
RESET	GPIO 4	RES	Hardware reset
DC	GPIO 16	A0	Data/Command select
CS	GPIO 17	CS	Chip select (active LOW)

Note

Software SPI is used to avoid bus conflicts with the radio. Both devices can operate simultaneously.

UART Configuration

UART2 — NEO-6M GPS

Signal	ESP32 GPIO	GPS Pin	Notes
RX	GPIO 22	TX	GPS TX to ESP32 RX (input-only)
TX	N/C	RX	unconnected - firmware never sends to the GPS

Baud rate: 9600 (NEO-6M default)

Audio Output

DAC1 Path

CODE

GPIO 25 (DAC1) --> 100 Ohm --> 10uF cap --> 3.5mm jack TIP

Components:

R2: 100 Ohm series resistor (current limiting)
C3: 10uF electrolytic (AC coupling, blocks DC)
J1: 3.5mm TRRS jack (Tip=audio, Sleeve=GND)

Tip

The ESP32 DevKit V1 has a native 8-bit DAC on GPIO 25. Audio is generated via LEDC PWM for precise frequency control.

Battery Monitor

Voltage Divider

CODE

TP4056 BAT+ --> R3a (100k) --> GPIO 36 --> R3b (100k) --> GND
                                |
                            ADC reading
                           (VBAT / 2)

Calculation:

Full charge (4.2V): ADC sees 2.1V
Empty (3.0V): ADC sees 1.5V
Quiescent current: ~21uA (negligible)

Note

GPIO 36 is input-only (ADC1_CH0, SVP). No external pullup needed.

LED Indicators

Red LED (BEACON Mode)

CODE

GPIO 27 --> 330 Ohm --> Red LED anode --> LED cathode --> GND

Blue LED (SEARCH Mode)

CODE

GPIO 26 --> 330 Ohm --> Blue LED anode --> LED cathode --> GND

Button Connections

MODE Button (GPIO 33)

CODE

GPIO 33 <-- [SW_MODE] --> GND

Internal pullup enabled in firmware.

SEL Button (GPIO 32)

CODE

GPIO 32 <-- [SW_SEL] --> GND

Internal pullup enabled in firmware.

UP Button (GPIO 35)

CODE

GPIO 35 <-- [SW_UP] --> GND
         |
         +--> 10k --> 3.3V (external pullup required)

DN Button (GPIO 34)

CODE

GPIO 34 <-- [SW_DN] --> GND
         |
         +--> 10k --> 3.3V (external pullup required)

Warning

GPIO 34 and 35 are input-only pins with no internal pullup. External 10k pullup resistors are required.

Power Supply

Main Power Path

CODE

USB 5V --> AMS1117-3.3V --> 3.3V Rail
                             |
Battery 3.7V --> TP4056 --> BAT+ --> 3.3V Rail

Decoupling

C1: 100uF electrolytic on 3.3V rail (bulk storage)
C2: 100nF ceramic on 3.3V rail (high-frequency decoupling)

Tip

For cold weather operation (< -10C), replace C1 electrolytic with a 47uF X7R ceramic capacitor.