YAMABIKO: Leave Your Voice in a Place, Off the Grid

What is your project about? 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 ## Hardware - M5Stack Core2 for AWS ×2 - M5 Mini GPS/BDS Unit (AT6558) ×2