A pocket e-ink VT100 terminal for the Xteink X4.

78 columns x 24 rows on an 800x480 e-ink display, connected via USB serial.

• VT100/ANSI escape sequences - cursor movement, erase, scroll regions, insert/delete lines and characters, SGR attributes
• Alternate screen buffer - estore the previous screen on exit (CSI ?1049h/l)
• 256-color & RGB - mapped to grayscale luminance with Bayer dithering
• UTF-8 - full BMP decode (U+0000-U+FFFF)
• Extended Unicode glyphs:
  • Latin-1 Supplement (pre-rendered from DejaVu Sans Mono)
  • Box drawing, block elements, quadrant blocks (algorithmic)
  • Braille patterns (algorithmic, 256 patterns)
  • Arrows, typographic punctuation, geometric shapes
• E-ink optimized rendering - partial updates for small changes, periodic full refresh to clear ghosting

• Xteink X4 (ESP32-C3, 800x480 e-ink)
• USB-C connection (CDC serial)

Requires PlatformIO and the open-x4-sdk (included as a git submodule).

git clone --recursive https://github.com/penk/X4Term.git
cd X4Term
pio run            # build
pio run -t upload  # flash

If you already cloned without --recursive:

git submodule update --init --recursive

Connect via USB and attach a serial terminal:

stty rows 24 cols 78
TERM=xterm-256color COLUMNS=78 LINES=24 script -q /dev/cu.usbmodem2101

The 10x20 bitmap font is generated from DejaVu Sans Mono (included in fonts/):

python3 -m venv .venv && source .venv/bin/activate && pip install Pillow
python3 scripts/generate_term_font.py
python3 scripts/generate_term_font.py --ext-ranges 00A0-00FF,2010-2027,2190-2199

src/main.cpp              - Entry point, serial/button handling, render loop
lib/VtParser/             - VT100/ANSI escape sequence parser, UTF-8 decoder
lib/TermBuffer/           - Terminal cell grid, cursor, scroll, alt screen buffer
lib/TermRenderer/         - E-ink framebuffer rendering with Bayer dithering
lib/TermFont/             - Bitmap font (ASCII + extended Unicode)
scripts/                  - Font generation and test scripts