Morse

Type a message. Send it as a melody, a tone, light or vibration — or build an ATAK data package to import. Everything happens on this device; nothing is uploaded.

Message Speed — 8 WPM · 150 ms per unit Sync preamble — a long opening mark so a camera can find the start and work out the timing itself. Costs about 1.7 s. Tone

Inaudible Bluetooth. Key 17 and 19 kHz at once for a speaker that still has the top of the band. If yours lowpasses, pick Melody instead — it is meant to be heard and every speaker will play it. AirPods still fail: they play into an ear, not the room.

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—duration

—characters

—elements

Transmit

Uses the camera torch if this device allows a web page to control it (Android Chrome). Otherwise the screen becomes the lamp — dimmer, but the camera receiver reads it fine at close range.

Data package

A standard ATAK mission package: the marker, the audio, the pulse timings, and a copy of this app. Import it on a device, or open the .wav anywhere.

Marker position (optional)

Melody is the default. The house loop is a stand-in bed — the Morse is a quiet concert A inside it. Save this page and it keeps working with no network at all. On a phone, use Share → Add to Home Screen and it behaves like an app.
To decode an incoming transmission on this device, open the listener — receive only, no transmitter.