Hey folks!

I've been working on a custom firmware for the Cardputer ADV (ESP32-S3) that turns it into a pocket SSH terminal with a big external display. Just released v0.6.0 — binaries only, no source (for now).

What it does

SSH Terminal (the main feature):

• Full SSH2 client implemented from scratch (curve25519 + AES128-CTR + HMAC-SHA2-256)
• Runs on the external 320×240 ILI9341 SPI display — 40×15 VT100 terminal with ANSI 16-color, blinking cursor, and Chinese character support (GB2312 bitmap font)
• Tested against OpenSSH 10.3 / zsh / vim / htop — full-screen TUI apps work
• Password auth, config stored in NVS, long-press key repeat (hold backspace to delete, hold arrows to move in vim)
• Flow control window management, so heavy output like cat doesn't stall

MP3 Player:

• SD card playback via esp-audio-dec hardware decode
• Dual-screen visualization: inner 240×135 shows controls, external 320×240 shows a Braun-style clock face + spectrum analyzer + track name
• Resume from last position, long-press seek, software volume with perceptual curve

Lunar Clock (3 modes, Tab to switch):

1. Large DSEG7 LED clock with blinking colon
2. Date + weekday + Chinese lunar calendar date
3. Full almanac page: four pillars (八字 BaZi), five elements (五行), daily auspicious/inauspicious activities (宜忌), and lucky clothing colors shown as little T-shirt icons

All verified against the cnlunar Python library for accuracy across 2,150 test dates.

Hardware

• Cardputer ADV (ESP32-S3, 8MB flash, no PSRAM)
• External ILI9341 320×240 SPI display (shares bus with SD card)
• The display connects via the Prokuon Cap TFT V2 adapter board

Keyboard

Follows the standard Cardputer layout:

• Plain , . / ; = type punctuation directly (for IPs and URLs)
• Fn + those keys = arrow keys
• Ctrl + letter = control characters
• Esc short = send ESC, long hold = exit app

Download

GitHub: https://github.com/hongxin/m5cardputer-xzyos

Binaries + flash script included. No source code at this time.

Made by Tim · XZYOS (小璋瑜OS) · v0.6.0

Would love feedback, especially from anyone with a Cardputer ADV + external display setup!