ESP32-C3 · open source

A pocket robot that talks back and pulls silly faces.

Dasai Mochi listens, thinks, and chats using your AI key — OpenAI, Groq, Gemini, your pick. When you're not chatting, it just sits there being adorable. Flash it straight from this page. No Arduino IDE, no drivers.

One-click install

Flash it from your browser

Plug the ESP32-C3 into your computer with a USB-C cable, hit the button, pick the port, and watch it go. This installs the prebuilt firmware — afterwards the bot makes its own WiFi hotspot so you can enter your WiFi & AI key.

1
Hold BOOT, plug inHold the BOOT button while connecting USB-C to enter flash mode.
2
Connect & installClick below, choose your board's serial port, confirm install.
3
Set up over WiFiJoin the DasaiMochi-Setup hotspot & enter your keys.
⚠️ Browser flashing needs the Web Serial API — please open this page in Chrome, Edge, or Opera on a desktop. Safari and Firefox can't flash.

After flashing: the bot reboots and creates a WiFi network called DasaiMochi-Setup. Connect your phone or laptop to it, and a setup page opens automatically where you choose your AI provider and paste your API key. Everything is stored only on the device.

Hardware

Wiring & pin map

Tap any connection to highlight it on the board. These are the default pins in config.h — easy to change if you wire it differently.

USB-C ESP32-C3 RGB

💡 The ESP32-C3-Zero hides GPIO 12–17 (used by onboard flash) and uses GPIO 9 = BOOT, GPIO 10 = onboard RGB LED. All audio/OLED pins below avoid those.

Bill of materials

What's inside Mochi

Everything is hobby-friendly and solderable on a small protoboard.

PartRoleInterface
Waveshare ESP32-C3-ZeroBrain + WiFi
SSD1306 0.96" OLEDThe face & statusI2C
INMP441 micHears youI2S in
MAX98357A + 2W speakerTalks backI2S out
3× TTP touch buttonsTalk / next face / modedigital
LiPo + TP4056 chargerPortable power3.7V
Slide switchOn / off
Why it's fun

More than a chatbot

🗣️

Talk & listen

Push-to-talk to ask anything — time, weather, news, or random questions. It replies out loud.

🔑

Your key, your model

Bring OpenAI, Groq, OpenRouter, Together, or Gemini. Switch any time in the setup page.

😜

Silly idle faces

Left alone, Mochi blinks, looks around, and cycles goofy expressions. Toggle a pure face-toy mode.

📡

Easy setup

No app. It hosts its own WiFi page to enter credentials — like setting up a smart bulb.

🔋

Truly portable

LiPo + charging module + slide switch. Pocket-sized companion that runs off a battery.

🛠️

Hackable

One clean Arduino sketch, parameterised faces, swappable pins. Fork it and make it yours.