Choosing a Build Configuration

Not everyone needs the full GPS-equipped field unit. Pick the configuration that matches how you will actually use the beacon.

The three reference builds

Build	Parts	Cost	Best for
Base rescue radio	ESP32, E22, OLED, buttons, audio	~$18	Learning, bench testing, first build
GPS edition	Base + NEO-6M	~$23	Backcountry users who want coordinates
Full field unit	GPS + rugged case + external antenna	~$28	Serious field use, team deployment

Base rescue radio

The minimum viable beacon: it transmits SOS in Morse, scans, and configures over WiFi. It has no GPS, so the payload is just SOS DE NAME (or plain SOS).

Choose this if:

• You want the cheapest possible working device.
• You are building to learn before committing to the full kit.
• Your use case is a fixed-location beacon (base camp, vehicle).

GPS edition

Adds the NEO-6M on UART2. The payload becomes SOS DE NAME PSN N4553 E01230, giving rescuers an actual position.

Choose this if:

• You will be moving (hiking, skiing, mountaineering).
• The difference between “a beacon is transmitting” and “here is where they are” matters to your rescue plan.

Full field unit

Adds a rugged enclosure, a proper external antenna, and sometimes a bigger battery. Runtime and range are the priorities.

Choose this if:

• The beacon is a piece of your safety kit, not a project.
• You operate in demanding terrain or weather.
• A team will carry and maintain several units.

Upgrading later

All three builds share the same firmware. The GPS is a drop-in addition (two wires + power), and the case is purely mechanical. Start with the base build and upgrade when you are ready; the firmware auto-detects the GPS setting from the dashboard.