Aegis-Beacon Documentation
Build, configure and operate the beacon with confidence
451 in-depth guides covering every component, every wire, every setting and every field scenario, from first power-up to full-scale search and rescue operation.
451wiki pages
16guide sections
100%open source
Onboarding
Start from zero: what the beacon is, the basics of radios, Morse and safety, and the learning path.
Budget Planning What the beacon really costs, where the money goes, and where you can save without hurting reliability. Common Beginner Mistakes The ten mistakes that cause the most forum posts, and how to avoid each one before it costs you a weekend. First Boot What should happen the first time you power the beacon, screen by screen, and what counts as normal. Learning Path A suggested reading order through this wiki, from complete beginner to confident field operator. Legal Basics for Beginners A plain-language overview of what you may legally do with a 433 MHz transmitter, and where to check your... How the Beacon Saves Lives The real-world scenario that motivates the whole project, and the design decisions that follow from it. Understanding the Modes in One Page BEACON, SEARCH, CONFIG and EMERGENCY explained with a real-world example for each. Morse Code for Beginners How Morse code works, how to read SOS, and the three letters that matter most for a rescue beacon. Parts Overview Every component in the beacon explained in plain language, before you buy anything. Reading the OLED Screens How to read every icon, bar, and line on the beacon display without the manual. Radio Basics for Complete Beginners What a radio signal is, what 433 MHz means, and why Morse still works when every digital network is gone. Safety First The non-negotiable safety rules for building and operating the beacon: battery handling, RF exposure,... Tools You Need The complete tool list for building an Aegis-Beacon, from a basic soldering iron to the nice-to-have extras. Using the BOM Builder How the interactive bill-of-materials builder works, how the budget fitter behaves, and how to use the store... Using the Interactive Demo How the web demo mirrors the real firmware, what you can learn from it, and how to use it before you own... Welcome to the Wiki What this wiki covers, how to navigate it, and the fastest path from a blank page to a working rescue beacon.
Getting Started
The practical path: parts, flashing, first boot, first transmission, and the FAQ.
Bench Power Powering the beacon on the bench with a supply or power bank, and the voltages you should measure. Bench Testing Basics The standard tests to run on a finished beacon before it goes in a pack: continuity, power, TX, RX, and GPS. Boot Process What happens between power-on and the first transmission: RTC restore, GPS wait, radio init Build Configurations Three reference builds: base rescue radio, GPS edition and full field unit, with the BOM deltas Choosing a Build Configuration Which of the three reference builds suits your use case, and how the BOM differs between them. Static Safety and ESD How to handle the ESP32 and modules without damaging them, in practical terms. ESP32 Troubleshooting Checklist A step-by-step checklist for the most common ESP32 problems in this beacon: no boot, no GPS, no TX, no... Frequently Asked Questions Answers to the most common questions about cost, legality, receivers, batteries and assembly First Transmission The safe, step-by-step way to make your very first Morse transmission and confirm it on a receiver. First Use Unboxing to first transmission: what to check, what the boot screen should show, and your first SOS on the air Project Overview What the Aegis-Beacon is, what it costs, how it works and where the project is heading Quick Start Guide From zero to a transmitting beacon in under 30 minutes: parts, flash and first boot Shopping List Where to buy the parts, how to spot clone pitfalls, and a realistic cost breakdown for 2026 Sourcing Parts Where to buy each component, how to spot clone pitfalls, and how to handle shipping and lead times. System Architecture How firmware, hardware and the WiFi dashboard fit together into one rescue system Troubleshooting Diagnose common failures: no boot, no radio, display glitches, GPS and power problems Version Selection Which firmware and hardware versions exist, what changed between them, and how to pick what to flash or buy... Workspace Setup A clean, safe, efficient bench layout for building and testing the beacon.
Power & Battery
Cells, chargers, regulators, current draw and the math of runtime.
18650 Battery Guide Protected vs unprotected cells, LiFePO4 for winter, holders and cold-weather capacity math 18650 Safety Notes Protected vs unprotected cells, why protection matters in a rescue beacon, and safe handling rules. Alternate Power Inputs USB power banks, solar, bench supplies and battery swaps in the field Battery Capacity Math How to estimate beacon runtime from battery capacity and average current draw, with worked examples for the... Battery Field Swap Swapping the beacon's cell in the field: the case access, the cold-weather technique, and the verification... Battery Monitor Calibration Calibrating the firmware's battery voltage readings: the ADC divider, the reference, and the two-point... Battery Monitor Details ADC chain, the 9-point Li-ion curve, calibration and the charging detect path Battery Selection and Management Guide to selecting, charging, and managing batteries for Aegis-Beacon Battery Storage Storing 18650 cells correctly: the storage voltage, temperature rules, and the calendar of checks that keeps... Battery Troubleshooting Diagnosing beacon battery faults: fast drain, no charge, sagging under TX, and the measurements that find the... Brownout Protection The ESP32 brownout detector: what it protects, how to read its resets, and the hardware fixes that stop the... Buck-Boost Converters How switching regulators turn the battery voltage into a clean 3.3 V, and why the beacon uses a regulator... Cell Chemistry Lithium-ion, LiFePO4, NiMH and alkaline compared for the beacon: voltage, capacity, cold weather and safety. Cell Discharge Curve Reading an 18650's discharge curve: the voltage plateau, the knee, and why voltage alone is a poor fuel gauge. Charger Troubleshooting TP4056 faults: no charge light, slow charging, overcharging, and the input requirements that make the charger... Charging and Cell Care Safe charging practice, storage voltage, cycle life and how the TP4056 protects the cell Cold Weather Batteries How cold destroys battery life, the symptoms to expect below zero, and the field techniques that keep a... Current Draw by Mode Reference table of the beacon's current draw in each mode and state, measured at 3.7 V. E22 Power Levels The E22 module's transmit power options, the current each level draws, and the legal mapping of each setting. ESP32 Power Input How the DevKit V1 is powered, what the AMS1117 does, and the safe ways to feed it from battery, USB, or a... First Power-On Protocol The step-by-step procedure for the first time you apply power, with the measurements to take at each step. GPS Power Saving The NEO-6M power modes, what the beacon's GPS power setting changes, and the battery trade-offs. Parallel Cells Running two 18650 cells in parallel for double runtime: the rules, the risks, and when it is worth it. Power Budget and Runtimes Worked runtime math for every mode, cell capacity and temperature scenario Power Management Deep sleep, RTC RAM, battery monitoring and realistic runtime estimates per mode Power Measurement How to measure the beacon's current draw in every mode with a multimeter, and the numbers you should see. Power Quick Reference The power numbers for the beacon in one place: draws, runtimes, thresholds, and the battery decisions. Protected vs Unprotected Cells The difference between protected and unprotected 18650 cells, and which one belongs in a beacon. Sleep Current The deep sleep current budget: which parts keep drawing after the ESP32 sleeps, and how to get a clean... Solar Build The beacon with solar charging: panel choice, the charging path, and the missions where solar actually pays... Solar Charging Charging the beacon from a solar panel in the field: what works, what the numbers say, and the honest limits. TP4056 Charger Guide The TP4056 USB-C charge module: BAT+, STDBY, DW01A protection and wiring to the ESP32 TP4056 Charging Current How the TP4056 sets its charging current, the programming resistor values, and the trade-offs of fast versus... TP4056 Wiring How to wire the TP4056 charger module into the beacon: input, battery, and the STDBY detection pin. Undervoltage Protection Protecting the cell from over-discharge: the firmware cutoff, the protected cell's circuit, and the...
Hardware & Components
Every module in the build: the ESP32, radio, OLED, GPS, display and input parts.
Audio Alert System DAC1 output stage, tone mapping per signal class, Morse click stream and volume control Audio Tone Details The exact tone map: SEARCH pitch progression, Morse clicks and the EMERGENCY tone ESP32 Board Variants DevKit V1, WROOM vs WROVER, 30 vs 38 pin, and what to check on clone boards Button Types Guide The tactile switches used by the beacon, their variants, and how to wire four buttons to four GPIOs with... Buzzer Types Active versus passive buzzers, the ones the beacon uses, and the drive circuit for each. E22 Module Pinout Every pin of the E22-400M30S explained: power, SPI, BUSY, DIO1, and the SMA antenna connection. E22 Radio Module Guide Ebyte E22-400M30S in depth: SX1262 inside, SMA, TCXO, PA, and why BUSY is mandatory E22 vs Bare SX1262 Why the E22-400M30S module is recommended over a bare SX1262 breakout, and when a bare module makes sense. ESP32 Board Guide Choosing and handling the ESP32 DevKit V1: variants, input-only pins, USB chips and board care ESP32 Board Variants DevKit V1 vs other ESP32 development boards, 30 vs 38 pin, WROOM vs WROVER, and what to check on clones. ESP32 Deep Sleep Hardware The hardware reality of deep sleep: what powers down, what does not, and the board-level fixes for a clean... ESP32 Flash and Partitions How the 4 MB flash is laid out, why partition tables matter, and what happens on a corrupt NVS area. ESP32 Input-Only Pins GPIO 34, 35, 36 and 39 have no output drivers and no pull-ups. What that means for the buttons and the ADC. ESP32 Sleep Modes How the beacon uses the ESP32 sleep states to stretch battery life, and what wakes it up ESP32 USB Chips CH340 vs CP2102, why the USB chip matters for flashing, and how to fix a board the PC cannot see. Firmware OLED Rendering How the firmware draws the OLED screen: the frame buffer, the 8x8 font, scrolling text and the mode screens. GPS Antenna Types The GPS antenna types used on the NEO-6M modules: ceramic patch, active versus passive, and the field... GPS Module Buying Guide What to check before buying a NEO-6M GPS module: patch antenna, backup battery, UART breakout, and clone... GPS Module Variants NEO-6M, NEO-7M, NEO-8M and M8N: what changes and what stays the same for the firmware Hardware Components Every part in the build: MCU, radio, display, GPS, battery and buttons, with the full BOM LED Status Indicators Red and blue LEDs: what the blink patterns mean in every mode LED Indicators Wiring The red and blue status LEDs: which GPIO, what resistor, and what the blink patterns mean. NEO-6M GPS Module Guide Choosing, wiring and placing the NEO-6M: UART2, patch antenna, and the RTC RAM backup role NEO-6M GPS Module How the NEO-6M is wired to the ESP32, how TinyGPS++ parses its NMEA sentences, and what 'fix' actually means NEO-6M vs NEO-M8N A practical comparison of the two GPS modules most often considered for this beacon, and why NEO-6M is the... OLED Display SSD1309 layout reference: every screen, battery icon state and the U8g2 rendering path OLED Library Notes Working notes on the SSD1306 display library: the API the firmware uses, performance traps, and the I2C... OLED Panel Guide SSD1309 vs SSD1306, I2C vs SPI breakouts, buying the right 7-pin panel and avoiding burn-in OLED Panel Life How long OLED panels last, the burn-in risk, and the firmware's screen management that keeps the display... OLED Panel Specs The 0.96 inch 128x64 OLED panel's specifications: controller, interface, voltage, and the variants that work... OLED SPI vs I2C Why the beacon uses a 7-pin SPI SSD1309, and how to tell SPI from I2C panels before you buy. Display Selection Guide How to choose and configure the display type for Aegis-Beacon: OLED, TFT, and LCD options with pin wiring and... Display GPIO and Pin Reference One GPIO/pin table per supported display: SSD1309 OLED, ST7735 TFT, HD44780 LCD 16x2 and 20x4, with the exact... ST7735 TFT Display ST7735 1.8 inch 128x160 color TFT on the Aegis-Beacon: exact pinout, the Adafruit_ST7735 software SPI... HD44780 LCD Displays HD44780 character LCD modules (16x2 and 20x4) on the Aegis-Beacon: full pin tables for the 16-pin header, the... Radio Library and SX1262 How the beacon talks to the SX1262 radio through RadioLib, the GPIO mapping, and the limits of TX power Radio Module Variants E22-400M30S vs bare SX1262 vs LLCC68 modules, and why the E22 is recommended
Build & Assembly
Wiring, soldering, enclosures, sealing and the bench test sequence.
3D Printing the Enclosure Guide to 3D printing and assembling the Aegis-Beacon enclosure Assembly Guide Complete step-by-step build: soldering order, wiring, mounting and first power-up of the beacon Assembly Sequence The recommended order of assembly that catches wiring errors before they are buried under other modules. Audio Jack Wiring The 3.5 mm TRRS jack, the DAC output path, and why the AC-coupling capacitor matters. Audio Troubleshooting Diagnosing the beacon's audio: silent buzzer, distorted jack output, and the level checks for recording and... Bench Checklist The complete bench test sequence for a new or repaired beacon, in order, with the pass criteria for each step. Breadboard Prototyping Bring the whole beacon up on a breadboard first: power, radio, OLED and GPS before soldering Building Your Own Case Design a custom enclosure from scratch: layout, cutouts, antenna exit and assembly Button Actions in CONFIG Mode Exactly what each physical button does once the device is in the WiFi configuration portal Button System Details Debounce, hold detection, auto-repeat and the timing constants behind every press Button Troubleshooting Diagnosing button faults: double-triggers, no response, phantom presses, and the debounce and wiring checks. Case Cutouts Guide Where and how to cut the enclosure: OLED window, buttons, SMA hole, jack hole, and the USB access. Case Materials Choosing the beacon case material: printed PLA, PETG, ABS, and off-the-shelf boxes, with the RF and... Circuit Description How every bus and rail is wired: SPI, UART, DAC audio, battery divider, LEDs and buttons Connector Types The connectors used in the beacon build: JST, Dupont, USB, SMA, and the current ratings that decide which one... Datasheet Reading Extracting what matters from the SX1262, ESP32 and NEO-6M datasheets: absolute ratings, pin tables, and the... Dummy Load and Bench Testing Test transmissions without radiating: a 50 ohm dummy load and safe bench procedure Electrical Specifications Absolute maximum ratings, power supply rails, per-state current draw and realistic battery life estimates Enclosure Options Aluminium box, 3D printed case, cutouts and waterproofing for field use Flux and Solder The types of solder and flux, when to add extra flux, and how to pick the right diameter. Glue and Adhesives The adhesives used in the beacon build: hot glue, epoxy, RTV silicone, and the rule about what each one is... GPIO Pin Map Reference One consolidated table of every ESP32 pin used by the beacon, with function, direction and notes GPIO Pin Mapping Complete v5.5 GPIO map: radio, OLED, GPS, audio, LEDs, buttons and ADC connections Ground Planes and Counterpoises Why a quarter-wave needs a ground plane, and how copper foil adds ~3 dBi Ohm's Law V = I x R, worked examples for the beacon's circuits, and the three practical uses in this project: LEDs,... Resistors, Capacitors and Passives Every passive component in the BOM explained: values, roles, and what happens if you substitute. Schematic Reading Reading the beacon's schematic: power rails, signal nets, and the five checks that catch wiring errors before... Screw and Fastener Guide The fasteners used in the beacon case: M2/M3 hardware, brass inserts, and the mounting pattern for boards and... Soldering Basics Tools, technique and joints for the Aegis-Beacon build: modules, wire and the SMA feed Soldering Iron Guide Choosing an iron, tips, temperatures, and the technique that makes clean joints on the beacon's modules. Two-Beacon Bench Test Verify the full TX/RX loop with two beacons on the bench before any field use Waterproof Build Taking the beacon to IP67: case sealing, connector treatment, and the assembly order that keeps water out of... Waterproofing and Enclosure Sealing IP ratings, sealing every opening and keeping moisture out of a field beacon Wire and Connectors Wire gauge, jumper types, and the connectors used across the beacon build. Wire Gauge Guide Choosing wire sizes for the beacon: the current table, the voltage-drop math, and the gauges the build... Wiring and Connectors Wire gauge, connectors and routing for the whole build: power, SPI, audio and buttons Wiring Order and Routing How to route the internal wires cleanly: power, SPI, UART, audio and the antenna feed. Wiring Quick Reference The wiring table for the whole build in one place: every connection, every pin, every colour.
Radio & RF Design
How the radio works: antennas, propagation, modulation, measurement and link budgets.
Antenna Cable and Connectors Coaxial cable and RF connectors for the beacon: SMA vs RP-SMA, coax loss at 433 MHz, and the right cable for... Antenna Design Antenna theory, quarter-wave lengths, antenna types and installation for maximum beacon range Antenna Efficiency What antenna efficiency means at 433 MHz, where the losses hide, and how to estimate whether your antenna is... Antenna Height Matters Why antenna height dominates range at UHF: line of sight, the Fresnel zone, and the difference between waist... Antenna Length Reference Quarter and half wave lengths per band, snow penetration loss and field antenna rules of thumb Antenna Mounting How to mount the antenna on the beacon case: SMA flange, panel mount, strain relief, and keeping metal away... Antenna Quick Select Choosing the right antenna for the mission: the decision table that matches antenna to situation. Antenna Testing and Tuning Verify an antenna is cut right: SWR, range checks and the 17.3 cm wire rule Antenna Theory Primer How an antenna works, why length matters, and the quarter-wave rule that gives the 17.3 cm wire. Antenna Troubleshooting The antenna fault checklist: broken coax, bad connectors, detuning, and the test sequence that isolates the... Antenna Design and Selection Guide to antenna types, design, and optimization for Aegis-Beacon Coax Loss Tables Reference tables for coaxial cable loss at UHF, and how to budget the losses in the beacon's link. dBm Explained What dBm means, the powers the beacon uses, and how to think about -9 to +22 dBm. Foliage Loss How trees and vegetation attenuate 433 MHz signals, with the numbers you can expect in forest, and what to do... The Fresnel Zone Why line-of-sight is not enough, how the Fresnel zone blocks signal, and what to do about it in the mountains. GPS Antenna Placement Ceramic patch orientation, distance from the radio and metal, and cold-start behavior indoors Half Wave Dipole The half-wave dipole for the beacon: balanced feed, no ground plane needed, and when it beats the... Helical Antenna The loaded helical antenna: how a coil of wire makes a short antenna resonant, and its trade-offs for the... Homebrew Antenna Building a simple, field-repairable 433 MHz antenna from parts: wire, SMA, and a soldering iron. Interference Sources at 433 MHz The real-world sources of noise and interference around 433 MHz, and how they affect SEARCH mode. Line of Sight and Terrain How mountains, ridges, and valleys shape the beacon's real range, with honest numbers for 433 MHz. LoRa vs FSK The two modulation modes of the SX1262: LoRa sensitivity versus FSK compatibility, and which the beacon uses... Modulation in the Beacon How the SX1262 produces Morse: FSK carrier keying, the RadioLib calls and receiver behaviour Morse Timing and Audio Sync How the 600 Hz click stream tracks the RF keying and why timing is to PARIS standard Mountain Effects on Radio How mountains shape 433 MHz propagation: ridge shadowing, valley trapping, knife-edge diffraction, and the... Propagation and Range What 433 MHz does in the real world: line of sight, snow loss, terrain and honest range expectations Propagation Modes How 433 MHz signals travel: line of sight, diffraction, reflection, and the rare ducting events that make UHF... Quarter Wave Antenna The quarter-wave whip: how it works, how long it is at 433 MHz, and why it needs a ground plane. Radio Quick Start The radio knowledge needed before the first transmission: the band, the channel, and the first range test. Radio Shadow The dead zones where a beacon signal disappears, why they exist, and the systematic way to find and escape... Receiver Testing How to test the beacon's receiver without a lab: sensitivity checks with a second beacon, attenuators, and... RF Basics for the Beacon dBm, RSSI, CW vs OOK, and the vocabulary used across this wiki RF Design & Link Budget Free-space path loss, link budget math and realistic range expectations for 410-525 MHz RF Exposure Safety Antenna placement, duty cycle and keeping a transmitting beacon away from eyes and head RF Interference and Noise Sources of noise at 433 MHz, how they affect SEARCH mode, and what to do about them RSSI Explained What the RSSI number in SEARCH mode means, how the threshold works, and how to interpret the hit log. Sensitivity vs Selectivity The two receiver qualities that decide what you hear: sensitivity finds weak signals, selectivity rejects... SWR Explained What standing wave ratio is, why 1:1 is the goal, and how to check the beacon's antenna without expensive... SX1262 Datasheet Notes The key numbers from the SX1262 datasheet that matter for this beacon: frequency, power, sensitivity, current... SX1262 Frequency Ranges The frequency capability of the SX1262 chip and the E22 module variants, and why the module's range limits... SX1262 Registers The SX1262 register map essentials: the configuration commands the firmware uses and the ones that cause most... Transmitter Testing Verifying the beacon actually transmits what it should: frequency, power, keying, and the dummy load... Tropospheric Ducting The weather phenomenon that carries 433 MHz signals far beyond normal range, and what to do when it happens. Troubleshooting RF Issues Diagnosing and fixing radio frequency problems with Aegis-Beacon Urban RF Environment What the 433 MHz band looks like in a city: density of devices, interference, and how to test the beacon... VSWR Measurement How to measure VSWR on a 433 MHz antenna without expensive gear, and how to read the results.
Frequencies & Regulations
The 433 MHz band, legal frameworks by country, licensing, and the emergency exception.
The 70 cm Amateur Band The amateur allocation at 430-440 MHz where the beacon can legally run at full power, with a license. Amateur License Process Getting your amateur radio license step by step: study, exam, application, and the callsign you will program... Austria Radio Legal Using the 433 MHz beacon legally in Austria: RTR rules, ISM limits, mountain rescue context and the emergency... Callsign Identification Why amateur regulations require periodic identification, and how to configure the beacon to send your... Duty Cycle Rules What transmit duty cycle is, the limits that apply in different regions, and how the beacon's schedule fits. Emergency Frequencies The frequencies rescue services and amateurs monitor, and where a beacon transmission is most likely to be... Emergency Use Legal The distress exception: when radio limits are legally suspended, where the boundary lies, and why it does not... ERP vs EIRP The difference between ERP and EIRP, how antenna gain changes the legal number, and which one your regulator... France Radio Legal Using the 433 MHz beacon legally in France: ANFR rules, ISM limits, PMR446 and the emergency exception. Frequency Compatibility Regional frequency table and compatibility guidance for legal beacon operation worldwide Frequency Planning Examples Real configuration examples for Europe, PMR446 channels and the hop sequence Frequency Table Reference The reference frequency tables for the beacon: the 433 MHz band plan, PMR446 channels, and the regional... Germany Radio Legal Using the 433 MHz beacon legally in Germany: BNetzA rules, ISM limits, and how the harmonized framework... ISM Bands Explained What an ISM band is, the 433 MHz allocation, and why "unlicensed" still means "licensed-free within limits". Italy Radio Legal Using the 433 MHz beacon legally in Italy: the ISM band rules, the 10 mW ERP limit, and the emergency... License Classes The amateur radio license classes across the main countries, what privileges each opens, and which one covers... PMR446 Deep Dive The license-free European radio service, its 16 channels, the 500 mW ERP limit, and how to configure the... Regulatory Compliance Legal requirements and frequency regulations for operating Aegis-Beacon Safety and Liability What this device is, what it is not, and how to use it responsibly Scanning the Band Using SEARCH mode systematically: sweep ranges, channel steps, and how to identify what you find on each... Switzerland Radio Legal Using the 433 MHz beacon legally in Switzerland: OFCOM rules, ISM power limits, and practical notes for the... UK Radio Legal Using the 433 MHz beacon in the United Kingdom: Ofcom rules, ISM limits, and the CEPT-derived framework. US Radio Legal Using the 433 MHz beacon in the United States: FCC Part 15 rules, the 433.92 MHz ISM allocation, and the...
Firmware & Software
The firmware architecture, configuration, build tools, serial debugging and the dashboard.
Arduino CLI Guide Building the firmware with the Arduino CLI instead of PlatformIO: setup, board package, compile, and flash... Boot Loop Troubleshooting The beacon that restarts endlessly: brownouts, watchdog resets, flash corruption, and how to catch the loop... Boot Screens and Errors Every boot-time screen state and the serial errors you may see on power-up Changelog Version history of Aegis-Beacon firmware and hardware, aligned with the repository DATASHEET Code Style Guide The firmware's coding conventions: naming, formatting, comments, and the review rules that keep the code... Config Backup Backing up and restoring the beacon's configuration: the serial dump, the file format, and the restore... Config Dashboard The website page that renders the firmware's own configuration dashboard: how the extraction works and how to... Why the Dashboard Uses System Fonts The WiFi config dashboard stopped loading web fonts in v5.5: configuration happens offline, so it now uses... CONFIG Payload Format How the dashboard builds the Morse payload from message, name, and GPS, and what each part of the payload... Configuration Reference Every firmware constant, NVS key, button binding and calibration procedure in one reference Dashboard HTTP API Captive portal access point settings and the /status, /save, /emergency and /factory endpoints Dashboard Rendering How the CONFIG dashboard HTML is stored in flash, served by the web server, and why the page can be updated... ESP32 ADC Guide Using the ESP32's ADC for the battery monitor: the pins, the reference, the nonlinearity, and the calibration... ESP32 Flash Security The flash security features available on the ESP32: secure boot, flash encryption, and what the beacon does... ESP32 Interrupts Guide How the firmware uses interrupts: the button edges, the radio's DIO line, and the rules that keep interrupts... ESP32 RTC Notes The ESP32's real-time clock: what it preserves, its drift, and how the beacon uses it for scheduling and... ESP32 Serial Debug Output What the firmware prints on Serial, the log macros, and how to interpret each log category ESP32 Timers Guide The timers the firmware relies on: millis for scheduling, the RTC timer for sleep, and the LEDC for tones. ESP32 WiFi Hardware The ESP32's WiFi radio: its hardware, its power cost, and why the beacon keeps it off except in the config... esptool Guide The low-level ESP32 flashing tool: when to use it, the key commands, and the recovery procedures PlatformIO... Extending the Serial Protocol Add new AEGIS: lines and serial commands to the firmware: where the code lives and the conventions to follow. Factory Reset and Recovery Wipe NVS, clear a stuck EMERGENCY flag, and get the beacon back to known-good defaults Firmware CW Decoder The internals of the LISTEN mode Morse decoder: sampling, mark and gap timing, symbol accumulation and the... Firmware System Monitoring Battery voltage measurement, board temperature and the RSSI history buffer in the v6.0 firmware Frequency Setting over Serial Set the beacon's desired frequency with the FREQ serial command, verify it, and persist it without the... The Button System in Firmware How presses, holds, debounce, and auto-repeat work inside the firmware, with the timing constants. How Firmware Loads Configuration The boot-time config path: NVS read, validation, defaults on failure, and the emergency flag check order. Firmware Deep Sleep How the ESP32 enters deep sleep between beacon bursts, what stays powered, and how the device wakes on... Firmware Error Codes The error codes the firmware reports on the OLED and serial debug output, and what each one means. Firmware GPS Handling How the firmware talks to the NEO-6M GPS module: UART wiring, NMEA parsing, fix acquisition and timeouts. The Firmware Main Loop How the ESP32 firmware is structured, what the main loop does every cycle, and how the watchdog fits in. Firmware NVS Keys The Non-Volatile Storage keys the firmware uses to persist configuration, and how to read or reset them. Firmware Overview Architecture of the ESP32 firmware: code structure, main loop, radio init and Morse TX path The Payload Builder How the firmware assembles the Morse message from message base, name, and GPS coordinates. Firmware RSSI Measurement How the firmware reads the SX1262 RSSI register, converts it to dBm, and uses it in SEARCH mode and in packet... The Scan Cycle in Detail How SEARCH mode walks the frequency list, samples RSSI, classifies hits, and logs them to RTC RAM. Firmware Scan Engine How the SEARCH mode sweeps frequencies, measures RSSI and reports the strongest signal in the band. The Firmware State Machine The states the firmware can be in, the transitions between them, and where each transition is triggered. Firmware Tone Generation How the firmware produces Morse tones on the buzzer and audio jack, with timing from the Morse standard. The TX Cycle in Detail What happens during one BEACON transmission cycle: frequency iteration, Morse keying, timing, and sleep. Firmware TX Scheduler How the beacon spaces transmissions: the sleep interval, repeat count, and the timing rules that keep the... Upgrading to v5.5 How to upgrade the beacon from v5.4 (or older) to v5.5: what changes, what carries over, and what to... Firmware Update in the Field Updating firmware away from a computer: the options, the risks, and why the beacon is designed to make... Firmware Wake Sources The ESP32 wake sources used by the beacon: RTC timer, GPIO buttons, and how the firmware distinguishes them. The Watchdog How the hardware watchdog prevents hangs, the 30-second window, and why the firmware must feed it during long... Benchmark Demo Mode Run the full beacon UI and Morse timing on a bench rig without a radio, battery divider or GPS receiver,... Flash Troubleshooting Diagnosing firmware flashing problems: no serial port, connection failures, wrong board, and the recovery... No Boot? Troubleshooting The beacon powers up but nothing happens. The systematic path from power to firmware. No Display? Troubleshooting The OLED is dark, dim, or showing garbage. Here is how to fix it, in order of likelihood. NVS Configuration Store How the ESP32 Non-Volatile Storage holds settings, what survives power cycles, and how save and factory reset... PlatformIO Guide Building the firmware with PlatformIO: project setup, environments, board definitions, and the commands for... RTC RAM State What survives deep sleep: boot and TX counters, scan hit log, GPS fix cache and the emergency flag Battery Logging over Serial Record the beacon's battery state over time with the STATUS command and the bridge, and what the numbers mean. Serial Bridge Guide Connect the beacon to a computer or phone over USB and push its GPS position to the official site... Serial Command Automation Drive the beacon's serial commands from scripts and CI: expect-style flows, batch configuration and... Serial Command Protocol The machine-readable AEGIS: protocol the firmware speaks over USB serial, and every command you can send it. Serial Debug System Log tag reference, colours, verbose mode and a healthy annotated boot log Serial Monitor Guide Using the serial monitor effectively: baud rates, the debug build's log levels, and reading the beacon's... Software Build Process Compile and flash with Arduino IDE or PlatformIO, plus CI, testing and debug workflow Unit Testing the Firmware Testing firmware logic on the host: what can be tested without hardware, the test layout, and what the CI... Upload and Monitor Flash the firmware with Arduino IDE or PlatformIO and read the live serial console What's New in v5.5 Everything that changed in Aegis-Beacon v5.5: serial protocol, commands, bridge, Report Position page and the... What's New in v6.0 The v6.0 release brings LISTEN mode with a live CW decoder, the battery monitor, board temperature reporting... WiFi and Security How the open access point works, its limits, and safe practices around CONFIG mode WiFi Configuration Portal Connect to the captive portal and configure frequency, power, GPS, audio and OLED WiFi Troubleshooting Diagnosing the config portal: no access point, no page, weak signal, and the security checks before using...
USB & Connectivity
Connecting the beacon over USB: cables, drivers, ports, phones, and the serial bridge that reports positions.
Android OTG Guide Plug the beacon into an Android phone with an OTG adapter and use serial terminals or the bridge in Termux. Bridge Automation Use the serial bridge headlessly: log positions to files, script sessions, and integrate with your own tools. Bridge Security Why the serial bridge only listens on 127.0.0.1, what data leaves your machine, and how the site talks to the... Bridge Troubleshooting Diagnose the serial bridge: no port, no positions, no page updates, port busy, and browser quirks. Bridge TUI The live terminal dashboard of the serial bridge: local position track, public share link, what every field... CH340 Driver Install Install the CH340 / CH341 USB-serial driver on Windows, macOS and Linux for clone ESP32 boards. CP210x Driver Install Install the Silicon Labs CP210x driver on Windows, macOS and Linux so the beacon's serial port appears. Report Position Page What the website's /report-position page does, how it fills itself in, and how to test it without hardware. USB-Serial Adapter Troubleshooting Diagnose why the beacon does not show up as a serial port: drivers, cables, permissions, ports in use and... Serial Port Detection Find the beacon's serial port on Windows, macOS and Linux, including what the port is called and how to... Termux: Serial Bridge on Android Run the Aegis-Beacon serial bridge on an Android phone with Termux and an OTG adapter, and stream positions... USB Cable Types How to tell a data cable from a charge-only cable, and which cables work for flashing, serial and bridge use. USB Connection Guide How to connect the beacon to a computer or phone over USB: ports, cables, drivers and what you can do once... USB Power vs Data What the beacon does over a power-only cable, a data cable, and an unpowered hub, and the pitfalls of each. Web Serial: Browser-Only Option Use the Web Serial API so a Chrome desktop browser talks to the beacon directly, without the Python bridge.
Morse & Communication
Morse code, decoders, phonetics, Q codes, radio etiquette and receiving the signal.
Audio Recording Guide Recording the beacon's Morse output cleanly: levels, input types, and the setup that decodes every time. Band Plan Etiquette How the 433 MHz band is organized in practice: channel spacing, the busy frequencies, and the unwritten rules... Decibel Table The dB reference table for the beacon: power levels, gains and losses, and the mental arithmetic that makes... Mayday vs Pan Pan The two voice distress prefixes, when to use which, and how to structure the call that follows. Morse Abbreviations and Prosigns What DE, PSN and other Morse shorthand mean in the beacon payload Morse Audio Cheat Sheet The audio Morse reference: what the beacon's tones sound like, the timing at each speed, and the listening... Morse Code Engine PARIS-standard timing, symbol encoding and the CW keying implementation on the SX1262 Morse Code Learning Apps The practical tools for learning Morse: apps, web tools, and the ones that pair with the beacon's own demo... Morse Decoder Tools Decode the beacon payload with software, SDR plugins, or a plain phone app Morse Code Background Why Morse survives: history, the PARIS standard, and why it still fits a rescue beacon Morse Keying Practice Practicing reading and sending Morse for beacon work: the timing drills, the learning curve, and what... Morse Listening Workflow How to listen to the beacon's Morse in the field: tuning in, reading the payload, and turning copy into a... Morse Letter Table The full Morse code table for letters and digits, with the patterns the beacon transmits. Morse Numbers and Punctuation Morse for numbers, punctuation and the prosigns the beacon uses in its payload. Morse Practice Exercises for copying the beacon's payload by ear and with software Morse Timing Reference Every unit, dot, dash and gap in milliseconds across the common WPM settings this beacon uses Payload Examples Real examples of the beacon's Morse payload, from the minimal SOS to the full identity-plus-coordinates... Phonetics The NATO phonetic alphabet and why spelling out callsigns and coordinates on voice channels prevents fatal... Q Codes The Q codes most useful for beacon work: QTH, QSY, QRM, QRN and friends, and what they mean on the air. Radio Communication Basics Calling, listening turns, repeaters and simplex etiquette around 433 MHz Radio Etiquette Basics The operating habits that keep the band usable for everyone: listening first, short transmissions, and the... Reading CW by Ear Learn to copy SOS and coordinates by ear: timing, practice patterns and the letters that matter Receiver Compatibility Which radios and receivers hear the 433 MHz CW signal, and how to tune them Rescue Communication Basics How radio communication works in a rescue context: who talks, what they say, and how the beacon fits into the... SDR Beacon Build Adding an SDR dongle as a permanent monitoring receiver for the beacon: setup, antennas, and turning a phone... SDR Decoding Morse Decoding the beacon's Morse automatically from an SDR recording: the software options and the settings that... SDR Listening Guide Hear and see the beacon with an RTL-SDR: setup, tuning and waterfall interpretation SDR Software Setup Setting up SDR software to receive the beacon: driver installation, tuning, and the waterfall reading. Signal Reporting Conventions RST-style reports and how to describe what you hear from the beacon Simplex Communication Simplex operation, the mode the beacon uses: one frequency, one direction at a time, and the rules that keep... Spectrum Analyzers Cheap spectrum analysis options for 433 MHz: RTL-SDR, TinySA, and what each can and cannot verify on the... Two-Way Build Turning the beacon into a two-way radio: pairing with PMR446 or amateur handhelds, and the architecture that...
Modes & Operation
The operating modes, screens, buttons and the scan engine.
Glossary of Modes and Settings Plain-language definitions of every mode, NVS key and dashboard setting BEACON Mode The primary emergency mode: TX cycle, payload building, deep sleep and how to configure it CONFIG Mode The WiFi configuration dashboard: entering it, what each section does, and safe use EMERGENCY Mode Continuous max-power SOS: activation, behavior, flag persistence and how to clear it LISTEN Mode Operating the LISTEN mode: real-time Morse CW decoding on the OLED, live audio pitch and the serial AEGIS:CW... SEARCH Mode Locate other beacons with the RSSI scanner: dwell, threshold, hit log and audio pitch Mode Screens and Icons Reading every OLED screen: headers, icons, progress bars and the adjustment overlay Operating Modes BEACON, SEARCH, LISTEN, CONFIG and EMERGENCY: what each mode does, when to use it and how to switch Scan Engine Details Inside SEARCH mode: dwell windows, peak RSSI sampling, hit classification and the rolling log
Field Operations & Rescue
The field playbook: deployment, search, signaling, emergencies, winter and the checklists.
Avalanche Rescue Operation How the beacon supports companion rescue: search modes, priorities and realistic limits Avalanche Safety Basics The fundamentals of avalanche safety for beacon users: the danger scale, the terrain, and how the beacon... Beacon Care Seasonal The seasonal maintenance cycle for the beacon: pre-season bench test, post-season inspection, and the storage... Beacon Log Template The test log format for bench and field sessions: what to record, why, and how the log catches regressions. Cleaning and Inspection The post-trip cleaning and inspection routine: what to clean, what to look for, and the signs that mean... Crevasse Rescue Glacier travel with a beacon: crevasse risk, the beacon's role in a fall, and the rescue response that... Distance Estimation from RSSI Turning an RSSI reading into a rough distance estimate, why it is rough, and the calibration walk that makes... Emergency Cheat Sheet The emergency version of the quick reference: the sequence, the signals, and the numbers, formatted for a... Emergency Communications Plan Who listens, on what, and when: making the beacon part of a realistic rescue plan Emergency Kit The beacon-adjacent emergency kit: the small pouch of items that make the beacon part of a working survival... Emergency Response Minute by Minute What actually happens in the first hour of an emergency with a beacon: the sequence, the roles, and what to... Emergency Response Scenarios Realistic uses: partner in trouble, group split, lost in weather - step by step Field Checklist The field version of the checklist: the deploy, the confirmation, and the periodic checks during a mission. Field Deployment Guide Practical guide for deploying Aegis-Beacon in real-world rescue scenarios Field Maintenance and Storage Between-trip care: corrosion, connectors, firmware updates and long-term storage Field Repair Kit The compact repair kit that fixes the beacon's most common field failures: antenna, battery, and connection... Field Signals Cheat Sheet All the field signals in one card: whistle, mirror, ground, and radio, with the meanings and the replies. First Aid Kit The mountain first aid kit: what to carry, what each item is for, and how the kit and the beacon work... Ground to Air Signals The standardized ground signals used to communicate with search aircraft, and how to make them readable from... Group Communication Plan The communication plan for a group carrying beacons: channels, schedules, call signs, and the coordination... Hiking Safety The core hiking safety practices that keep the beacon as a backup rather than a primary plan: pace,... Homing Technique Walking to a beacon by its signal: the systematic approach that uses RSSI and terrain, not luck. Homing with the Serial Bridge Combine SEARCH-mode direction finding with the bridge's position stream to close in on a beacon efficiently. Hypothermia Recognition Recognizing hypothermia in yourself and your partners, and what to do before it becomes an emergency. Incident Command How a rescue incident is organized, what the beacon operator should know, and how to report in a way that... Long Term Storage Putting the beacon away for months or a year: the preparation, the cell decision, and the revival procedure. Mirror Signaling Aiming a signal mirror at an aircraft or distant searcher, the sighting technique, and why a mirror beats a... Mission Debrief Turn a mission's logged positions and scan hits into a debrief: track review, timing, signal reports and... One Bridge, Several Beacons Log positions from multiple beacons with a single bridge, one USB port at a time, and how to keep them apart. Night Operations Beacon work at night: why radio is the primary signal, the audio cues, and the operating differences from... Off-Grid Position Sharing Share beacon positions with no internet: bridge links over mesh, serial copy, and radio voice relay. Outdoor Testing Guide How to conduct range tests, environmental tests, and field validation Pack Check Routine The before-every-trip beacon check: charge, payload, transmission, seals, and the five-minute habit that... Position Logging Workflow Capture every beacon position during a mission: bridge setup, live tracking, and the log you keep afterwards. Pre-Trip Checklist Five minutes before leaving: battery, frequency plan, payload, and a live test transmission Repeater Position Reporting Send and receive beacon positions through repeater and relay networks, and the limits the SX1262 puts on tone... Ridge Crossing Technique Getting a signal across a ridge: the diffraction point, the crest rule, and why a few meters of height win... Safety Guidelines Critical safety information for operating Aegis-Beacon emergency radio equipment Safety Quick Rules The non-negotiable safety rules for building and using the beacon: the battery, the RF, the field, in ten... Search Patterns and Procedure Grid, spiral and audio homing patterns for locating a beacon with SEARCH mode Signal Strength Mapping Turning RSSI readings into a mental map of the coverage: walking a route, marking levels, and finding the... Signal Triangulation Locating a beacon from two or three listening points: the bearings, the intersection, and the honest accuracy... Signaling Techniques The full signaling toolbox: radio, whistle, mirror, fire, and ground signals, and how to choose the right one... Snow and Signal Behavior How wet and dry snow attenuate 433 MHz, with burial-depth loss numbers Snow Shelter Signaling Signaling from inside a snow shelter: how the beacon's signal escapes, the antenna placement, and the... Snow Signal Math The measured loss of 433 MHz in snow by depth and wetness, and what it means for a buried beacon. Storm Operations Operating the beacon in a storm: what the weather does to the radio, the battery, and the plan, and the... Terrain Reading for Radio Reading a map and the landscape for radio paths: where the signal will work, where it will die, and the... Trip Planning Planning a trip with a beacon: route information, the beacon plan, and the paperwork that turns a device into... Water Damage Recovery What to do when the beacon gets wet: the immediate steps, the drying procedure, and the corrosion cleanup... Weather Planning Reading a mountain forecast, recognizing the weather decision points, and how weather changes the beacon plan. Whistle Signals The whistle code used in mountain rescue: six blasts for distress, three for reply, and how to make a whistle... Winter Operations Cold-weather behavior, battery strategy, glove-friendly operation and snow considerations Winter Pack Packing the beacon for winter: the cold-specific additions, the battery strategy, and the checks that winter...
Building Effectively
How to plan, execute and log a build so it works the first time: stage order, quality gates, fixtures, rework and time planning.
Effective Build Strategy Plan the build like a staged project so every module is tested before it is buried under the next one. Build Quality Gates The measurable checkpoints that catch faults at the stage boundary instead of after the enclosure is sealed. Bench Jigs and Fixtures Simple homemade fixtures that make bench testing faster, safer and repeatable. Rework and Desoldering Remove and repair solder joints cleanly, without lifting pads or killing components. Build Time Planning Realistic time estimates per stage, what takes long, and how to parallelise ordering with building. Build Log and Tracking Track parts, stages and measurements so any fault can be traced to its cause and the next build is faster.
Build Variants
Alternative builds and multi-beacon setups: minimal, displayless, GPS-focused, solar and more.
Displayless Build The beacon without an OLED: GPS and audio kept, configuration by serial or WiFi, and the build decisions that... Minimal Build The smallest possible beacon: ESP32 plus radio and battery, no OLED or GPS, and what you give up for the size. Multi-Beacon Network Deploying several beacons as a coordinated network: channel planning, interference avoidance, and what each... Multi-Beacon Operations Several beacons in one group: frequency planning, scanning conflicts and SEARCH behaviour Multi-Beacon Frequency Planning How to plan frequencies when a group carries several beacons, and how to avoid them stepping on each other. Repeater Beacon Using a second beacon as a hilltop relay: the placement rules, the frequency split, and the honest limits of... Standard Build Configuration The recommended standard beacon build: every part, the wiring order, and the settings that make it a complete...
Project & Reference
The project itself: history, roadmap, contributing, releases, SEO and the quick references.
Acknowledgements The people, projects and communities the beacon builds on: libraries, testers, and the open source ecosystem. Attribution and License MIT terms, crediting the project and using the name and logo Benchmark Methodology How the automatic benchmarks are measured, on which runners, what each number means, and how to reproduce... Beacon Settings Reference The complete settings catalogue: every configuration value, its range, its default, and where it is... Branding The project's visual identity: the beacon mark, the palette, the typography, and how the website and wiki... CI/CD The automated checks that gate every change: what CI runs, what CD does, and how to read a failure. Commercial PLB vs DIY An honest comparison between the Aegis-Beacon and commercial personal locator beacons: cost, reliability,... Community Resources Where the project community lives: the repository, the issue tracker, and the places to discuss the beacon. Comparison with Alternatives How Aegis-Beacon compares to commercial and open-source emergency communication devices Configuration Quick Guide The fast path to a configured beacon: the settings that matter, the order to set them, and the verification. Contact and Support How to get help with the beacon: the issue tracker, the documentation, and the information that makes help... Contributing to Aegis-Beacon How to contribute code, hardware designs, documentation, and testing Deployment How the website is built and deployed: the build pipeline, the hosting platform, and what happens on every... Feature Requests Proposing a new feature for the beacon: describing the use case, checking the roadmap, and what makes a... Git Basics The git workflow for the Aegis-Beacon project: cloning, branching, committing, and the contribution flow. GitHub Workflow Guide Using GitHub for the project: issues, pull requests, releases, and the CI checks that gate every change. Glossary Plain-English definitions of every technical term used across the Aegis-Beacon project Project History How Aegis-Beacon came to be: the design journey from prototype to the current firmware, and the decisions... Quick Reference Sheet The one-page quick reference for the beacon: default settings, button actions, and the numbers every user... Release Process How firmware releases happen: version numbering, the changelog, the release checklist, and what users should... Reliability & Safety Features Watchdog, NVS fail-safe, interrupt-driven buttons, mid-TX abort and the EMERGENCY flag design Reporting Issues Filing a useful bug report: the information a maintainer needs, the format, and what makes a report... Roadmap Where the project is going: planned firmware features, hardware directions, and documentation goals. Robots and Sitemap The robots.txt and sitemap files: what they contain, why they exist, and how they are generated and verified. SEO How the site's search visibility works: meta tags, structured data, sitemap, and the rules every new page... Test Procedures Overview The index of every test procedure in the wiki: which test answers which question, and where each one lives. Translations The state of wiki translations, how translations are maintained, and how to contribute one. Unit Conversions The unit conversions that come up constantly in this project: inches to mm, feet to meters, miles to km,... Why 433 MHz The reasoning behind the beacon's band choice: license-free operation, universal receivers, propagation, and...
Prefer a hands-on approach?
Try the interactive firmware simulation or calculate the exact bill of materials for your build.