I2C-DISPLAYD(1)

📦
version 0.5.6 · 3 versions
, in fedora 44

💖 I2C-DISPLAYD 💖

okay bestie, gather round, because this is the manual page for i2c-displayd, a User Commands classic, and it's genuinely so much cooler than it sounds. it's the I2C display controller for single board computers. yes. tiny screens. big main character energy. ✨

🌸 NAME 🌸

i2c-displayd — I2C display controller for single board computers 🖥️💅

✨ SYNOPSIS ✨

i2c-displayd [-config path] [-mock] [-validate-config] [-test-display]

like, four flags, that's it, no cap. 🎀

🦋 DESCRIPTION 🦋

so i2c-displayd drives little OLED and TFT displays that are hooked up to single board computers — think Raspberry Pi, Rock 3C, etc. — over I2C or SPI. it literally just shows rotating pages of system stats for you: disk, RAM, and CPU temperature, plus network interface info. it's giving "tiny dashboard, enormous vibe." 🔥

the display types it supports include:

  • SSD1306 (I2C)
  • ST7735 (SPI)
  • UCTRONICS colour displays (I2C bridge)

three icons, honestly. obsessed. 👑

💅 OPTIONS 💅

  • -config path — path to a JSON configuration file. if you don't specify one, the daemon goes looking for config in /etc/i2c-display/config.json first, and then falls back to built-in defaults. it's very "if you don't text me first I'll assume we're fine" of it. 🙈
  • -mock — use a mock display for testing when you have no hardware. fake screen, real vibes. 🧚
  • -validate-config — validate the configuration file and then exit. returns exit code 0 if it's valid, non-zero otherwise. basically a vibe check for your config. ⭐
  • -test-display — run a hardware test pattern on the display and exit. it cycles through solid white, border rectangle, diagonal lines, text rendering, and clear. a whole runway walk for your screen. 🌈

🎀 FILES 🎀

  • /etc/i2c-display/config.json — the default configuration file. the one it reaches for first. 🫶
  • /usr/lib/systemd/system/i2c-display.service — the systemd service unit file. this is how it gets its life together on boot. 💜

🌟 EXIT STATUS 🌟

  • 0 — successful operation (or a valid configuration when you used -validate-config). slay. ✨
  • non-zero — an error occurred during startup or during configuration validation. 💀 not slay.

🍓 EXAMPLES 🍓

run it with a specific configuration file:

i2c-displayd -config /etc/i2c-display/config.json

test your display hardware:

i2c-displayd -config /etc/i2c-display/config.json -test-display

validate the configuration without starting the daemon:

i2c-displayd -config /etc/i2c-display/config.json -validate-config

🌸 SIGNALS 🌸

  • SIGHUP — reload the configuration file without restarting the daemon. glow-up mid-run, no restart needed. 💖
  • SIGUSR1 — wake the display immediately if the screen saver is active. the display stays on for the configured wake_duration (default 30 seconds) before it goes back to normal screen saver behaviour. this is equivalent to curl -X POST http://localhost:9090/wake when the metrics server is enabled. it's the "bestie I'm here" tap. 😭🫶

⭐ SEE ALSO ⭐

🙈 BUGS 🙈

report bugs at https://github.com/ausil/i2c-display/issues — please and thank you, the maintainers deserve the tea. 🎀

👑 AUTHOR 👑

Dennis Gilmore <dennis@ausil.us>

so yeah, that's the whole page. every flag, every path, every signal, every exit code, all present and accounted for. no details were harmed in the making of this rewrite. 💅

and that's a wrap, bestie — this was i2c-display version 0.5.6, dated September 2026, signing off. periodt. 🌈💖

📦 where this page comes from