Serial uploader was crashing the Pico when launching games because
it accessed SD card (SPI) while Core 1 was refreshing display (also SPI).
Display and SD card share the same SPI bus and cannot be accessed
simultaneously.
Split game launch into prepare and execute phases:
- prepare: Re-scan games directory (safe, SD access done immediately)
- execute: Load Lua script from SD (deferred until display is idle)
Main loop now checks !is_refresh_in_progress() before completing
launch, preventing SPI conflicts.
Also updated SD card best practices skill to document SPI bus
contention as the #1 most critical issue to avoid.
Co-Authored-By: Claude <noreply@anthropic.com>
Implements a complete serial upload workflow that allows uploading and
immediately testing Lua games via USB serial connection.
New Components:
- SerialUploader: Receives files via serial, writes to SD card
- upload_game.py: Python tool for sending files from host computer
- Protocol: Text-based with base64 encoding for reliability
Key Features:
- Uploads file to /games folder on SD card
- Overwrites existing files (FA_CREATE_ALWAYS)
- Auto-launches uploaded game immediately
- Proper memory cleanup (prevents Lua state conflicts)
SD Card Fixes:
- Fixed SPI speed management (12.5MHz for SD, 32MHz for display)
- Fixed SD write protocol (poll for data response token)
- Added speed switching wrappers around all FatFS operations
- Cleaned up excessive debug output
Game Launcher Improvements:
- Added clear_games() to prevent duplicate registrations
- Added cleanup in select_game_by_name() to delete old instances
- Added exact match priority in game selection
- LuaGameLoader now has clear_factory_data() for memory cleanup
Integration:
- Added serial_uploader to CMakeLists.txt
- Integrated into main loop in basic1.cpp
- Re-scans games after upload to pick up new files
Documentation:
- UPLOAD_TOOL.md: Usage instructions
- sd_card_best_practices.md: Critical lessons learned
Known Issues:
- Game launch after upload occasionally causes freeze (needs investigation)
- Display may not refresh properly after upload
Usage:
python upload_game.py games/lua_examples/2048.lua /dev/tty.usbmodem101
Co-Authored-By: Claude <noreply@anthropic.com>
