M5Stack Cardputer OpenClaw Client

An interactive prompt client running on the M5Stack Cardputer (ESP32-S3) that communicates with an OpenClaw AI agent gateway over Wi-Fi.

Features

• Romaji-to-hiragana conversion engine (full kana coverage including voiced, combo, double consonants)
• Japanese / ASCII input mode toggle
• LCD display for dialogue UI (idle / input / sending / response / error states)
• HTTP communication with OpenClaw via HTTP bridge server
• Wi-Fi connection status display on startup
• Built with PlatformIO + Arduino framework

Hardware

Component	Detail
Board	M5Stack Cardputer
SoC	ESP32-S3FN8 (Xtensa LX7 dual-core, 240 MHz)
Display	1.14" TFT ST7789V2 (240x135)
Input	56-key keyboard
Connectivity	2.4 GHz Wi-Fi, USB-C

Project Structure

software/cardputer-client/   PlatformIO project (firmware source)
  src/config.h.example        Wi-Fi / OpenClaw connection settings template
  src/main.cpp                Entry point
  src/dialogue_manager.*      Session state machine and keyboard handling
  src/prompt_input.*          Romaji-to-hiragana conversion engine
  src/display_manager.*       LCD rendering
  src/network_client.*        Wi-Fi + HTTP client
docs/
  system-spec.md              System specification
  feature-romaji-input.md     Romaji input feature spec
  feature-http-bridge.md      HTTP bridge feature spec
  toolchain-spec.md           Toolchain and build documentation
  requirements.md             Requirements specification
  troubleshooting.md          Troubleshooting guide
tests/                        Python unit tests (state machine, communication)

Quick Start

Prerequisites

• Raspberry Pi (or any Linux host) with Python 3 and USB connection to Cardputer
• PlatformIO Core CLI
• OpenClaw gateway running on the Raspberry Pi
• HTTP bridge server running on the Raspberry Pi

Build & Flash

# Set up environment
python3 -m venv .venv
source .venv/bin/activate
pip install platformio
export PLATFORMIO_CORE_DIR=/mnt/ssd/.platformio  # optional: use SSD storage

# Configure
cp software/cardputer-client/src/config.h.example software/cardputer-client/src/config.h
# Edit config.h with your Wi-Fi credentials and Raspberry Pi IP

# Build
cd software/cardputer-client
pio run --environment m5stack-cardputer

# Flash (replace /dev/ttyACM1 with your actual port)
pio run --target upload --environment m5stack-cardputer --upload-port /dev/ttyACM1

See docs/toolchain-spec.md for detailed toolchain documentation and troubleshooting.

Usage

1. Press any key on the idle screen to start input mode
2. Type your prompt using the 56-key keyboard
   • Tab — Toggle between Japanese [あ] and ASCII [A] input mode
   • In Japanese mode, type romaji (e.g. konnichiha) to get hiragana (こんにちは)
   • Del — Delete last character
3. Enter — Send prompt to OpenClaw and display the AI response
4. Esc (Fn + `) — Return to idle screen from any state
5. On the response/error screen, press any key to start a new prompt

License

See LICENSE for details.