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mangavalkandClaude Opus 5.5
f1dbc35ebd
- Commands run on '\n' instead of busy-waiting for a byte count, which fixes s/F/T waiting for the next command and P drawing 0xFF garbage - Invalid bitmaps no longer leak their data as commands; bitmap data is streamed so full-screen bitmaps still fit - Store flip time as uint16 with magic marker, validate 50-2000 us - Overflow-safe millis() handling for the periodic refresh - Run the full refresh only after D or when serial is idle, so incoming data is not lost while the redraw blocks - Put the boot refresh measurement behind MEASURE_REFRESH - Fix DEBUG hex output and use F() strings to save RAM - Driver: direct mode now updates the old buffer instead of re-setting the new one Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2.8 KiB
2.8 KiB
Flipdot display: notes for Claude
A PlatformIO project with two firmware targets for an 84×19 Brose flipdot clock. See README.md for the overview.
Layout and build
platformio.inihas the environmentsnano,esp32(OTA to 10.1.1.198) andesp32_usb(COM11). The sources are split withbuild_src_filter(src/nano/,src/esp32/).lib/BROSE9323/is the shared driver. Its behaviour depends on build flags set inplatformio.ini, not in the header:ESPSERIAL(ESP32): draw calls become serial commands.FLIPDOT_PLCC_ADAPTER(Nano, optional): alternative pinout.
- PlatformIO CLI is not on PATH. Run
~/.platformio/penv/Scripts/pio.exe run(Git Bash) or$env:USERPROFILE\.platformio\penv\Scripts\pio.exe run(PowerShell). - If an ESP32 build fails with
No module named 'intelhex', run~/.platformio/penv/Scripts/python.exe -m pip install intelhex. - After any change, build both targets:
pio run -e nano -e esp32.
Constraints
- Nano RAM is tight (ATmega328P, 2 KB). The frame buffers are allocated with
calloc. AvoidString, large stack buffers and new globals in Nano code. Put constant data inPROGMEM. - The Nano and the ESP32 share one UART. On the ESP32,
Serialis the display link, so don't print debug output on the ESP32'sSerial: the Nano would read it as commands. The Nano ignores unknown command bytes, but text that starts with s/S/F/D/P/B/R/T will be run as a command. src/esp32/secrets.hholds the real credentials and is gitignored. Never commit it. Add new secrets tosecrets.example.has placeholders.- Hardware is not available here. Builds can be checked, but runtime behaviour can't.
Nano serial parser (src/nano/main.cpp)
- Line based and non-blocking: bytes are collected into a 64-character buffer and a
command runs when
\narrives. Bitmap (B) pixel data is the exception. It is drawn while it arrives, so it can be longer than the buffer. Keeploop()free of busy-waits. - A full redraw (
display(true)) blocks for about 0.5 s, which overflows the 64-byte serial receive buffer. Only run it when no data is expected: right after aD, or after 2 s with no serial data. The ESP sends one frame per second, ending withD. - Flip time is stored in EEPROM as a magic word at address 0 and a
uint16_tat address 2. Values outside 50–2000 µs are rejected. - The Nano doesn't send an acknowledgement. Whether the Nano's TX is wired to the ESP's RX is unknown, so don't make the ESP wait for replies.
- To test the parser without hardware, compile
main.cppwith g++ (Strawberry Perl provides it atC:\Strawberry\c\bin) and mock headers forArduino.h,EEPROM.handBROSE9323.h.
Git
- Remote: https://mangavalk.com/mangavalk/Flipdot-display.git, branch
main.