Deep in the mountains, your phone shows “No Service.” YAMABIKO turns
that dead zone into something you can still talk through.
Pin a voice message to a place. When your partner arrives, it plays
itself. No cell towers, no Wi-Fi, no phone — just two devices, off-grid.
At a trail fork, record “take the left path here, the chain section
is wet.” Ten minutes later, when your partner reaches that exact
spot, their device plays your voice back automatically — an echo
that finds you.
Built on M5Stack Core2 for AWS ×2 and a Mini GPS/BDS unit, YAMABIKO
pairs automatically over ESP-NOW — no WiFi, no setup. Two devices,
straight out of the box.What it does
– **Voice messages**: hold a button, speak, release — the recording
is auto-leveled (soft voices get boosted, loud ones never clip)
and sent as data, so it survives weak signal without crackling
– **Voice treasures**: leave a voice note pinned to GPS coordinates;
your partner’s device plays it automatically when they arrive
– **Games**: hide-and-seek (LED color + heartbeat vibration as your
only clue), GPS tag, and treasure hunts — all using the same
location-sharing core
– **Morse code**: when even voice can’t get through, tap out a
message key-down/key-up in real time — your partner’s device
lights up and buzzes in the same rhythm as you type
– **Fall-detection SOS**: freefall → impact → stillness sequence
(not just “shaken hard”) to avoid false alarms; broadcasts your
GPS position with a bearing arrow on your partner’s screen
