Companion
Expressive idle face, motion-aware gaze, mood state, friendly phrases, charging animation, and low-power sleep.
In progress
Moji
Moji is a pocket-sized companion on an ESP32-C3 with an expressive face, games, tools, custom messages, and a local management portal.
In progress. Firmware v1.0.0 is running with the current menu, apps, management portal, and low-power behavior.
The idea
Moji is meant to feel like a small companion with a mood, not a breadboard demo. It runs real ESP-IDF firmware, spends most of its life asleep, and still reacts when you pick it up. The firmware is organized around one on-device menu and a local web portal for everything that is easier from a phone or laptop.
Current firmware
Two-button UI
On the face, left and right clicks make Moji glance toward the button. Pressing both opens the menu. Inside menus, left and right move through items and a held right button enters the selected item. The same hold feedback shows up in the setup flow and menu navigation.
Display bring-up
SSD1315 over 3-wire SPI (D/C bit in-band). CS toggles per byte on this board. Segment/column remap is ignored by the panel, so orientation is fixed at flush while draw code keeps normal coordinates. Flush promotes to a full frame when any page is dirty to avoid tearing.
Power
Active → idle → light sleep → deep sleep. Charging inferred from ADC trend (no charge-detect pin). Buttons wake from deep sleep; IMU wakes from light sleep only. Radio-heavy modes block at ~15%. At ~5%, state flushes to NVS and the device drops to deep sleep on purpose.
Capabilities
Play
Connect, Pong, Reaction, Tilt Maze, Dice, and Coin Flip.
Tools
Level, Flashlight, Timer, and Stopwatch.
Device
Stats, display controls, sleep, about, and factory reset.
Management
Local SoftAP portal for setup, settings, custom messages, status, and OTA firmware upload.
Architecture
Focused ESP-IDF components. ISRs only queue events; a UI/behavior task does the work.
moji_input
Button ISRs and battery ADC into a FreeRTOS queue.
moji_display
SSD1315 9-bit bit-banged SPI, staged framebuffer flush.
moji_face
Parametric eyes/mouth from a single mood state.
moji_nav
Shared scroll + long-press-release select and text entry.
moji_behavior
Mood metrics with decay, persisted in NVS.
moji_shell
App switching and power state machine.
moji_ble_hid
BLE HID mouse support.
moji_link
ESP-NOW link for paired play.
moji_portal
SoftAP web UI and OTA.
Manual
Owner controls, modes, and power behavior.