Display-O-Tron toolkit

This repo tracks local scripts and service files for a Raspberry Pi with a Pimoroni Display-O-Tron HAT.

Layout

• scripts/displayotron-check.sh - hardware/software smoke checks, optional demo write
• scripts/displayotron-status.py - boot-time status display loop (IP + uptime)
• scripts/displayotron-menu.py - touch-driven settings menu for backlight/contrast/service mode
• scripts/displayotron-notify.py - temporary notification overlay on the LCD + side LEDs
• scripts/displayotron-safe-unplug.py - shutdown hook display message for safe unplug indication
• scripts/displayotron_common.py - shared settings/theme helpers used by scripts
• scripts/deploy-to-pi.sh - deploy tracked scripts and service files to a Raspberry Pi device
• config/displayotron-settings.json - tracked settings file deployed to the Raspberry Pi device
• systemd/displayotron-status.service - systemd unit for the status display loop
• systemd/displayotron-safe-unplug.service - systemd unit that shows "SAFE TO UNPLUG" during shutdown
• docs/displayotron-operations.md - quick operations reference

Requirements

• SSH access to the Raspberry Pi device (rpi host alias in your SSH config)
• Passwordless sudo for the Raspberry Pi user (already configured)
• Display-O-Tron stack installed on the Raspberry Pi device

Development

Install test dependencies:

python3 -m pip install -r requirements-dev.txt

Run local checks that do not require hardware:

python3 -m compileall -q scripts
bash -n scripts/displayotron-check.sh
bash -n scripts/deploy-to-pi.sh
python3 -m pytest -m "not pi" -q

Deploy

From this repo root:

bash scripts/deploy-to-pi.sh --enable --start

If your SSH alias is not rpi, pass an explicit SSH target:

bash scripts/deploy-to-pi.sh --host user@your-pi-host --enable --start

Verify

ssh rpi "displayotron-check"
ssh rpi "systemctl status displayotron-status --no-pager"
ssh rpi "systemctl status displayotron-safe-unplug --no-pager"
ssh rpi "displayotron-check --leds"
ssh rpi "displayotron-notify --text 'Reply ready. Please check terminal.' --r 255 --g 0 --b 0 --brightness 50 --seconds 5"

Status pages and touch controls

displayotron-status now has two pages:

• Page 1: large 3-line HH:MM digital clock
• Page 2: IP + uptime

Touch controls while status is running:

• LEFT/RIGHT: switch pages
• UP/DOWN: brightness down/up in 10% steps
• CANCEL (back): open displayotron-menu

Status and menu touch handlers apply debounce to reduce accidental double inputs. Clock colon blink can be toggled in displayotron-menu via ClockBlink.

Safe unplug indicator

After deploy, shutdown automatically triggers a Display-O-Tron message:

• line 1: SAFE TO UNPLUG
• line 2: SYSTEM HALTED
• line 3: REMOVE POWER

This is wired via displayotron-safe-unplug.service and runs on halt/poweroff targets. The shutdown indicator keeps side LEDs off.

Settings source of truth

• Repo file: config/displayotron-settings.json
• Deployed file on the Raspberry Pi device: /home/pi/.config/displayotron/settings.json

displayotron-menu and displayotron-status both read the same deployed settings file. Editing config/displayotron-settings.json in this repo and redeploying will update live behavior.

Touch settings menu

ssh rpi "displayotron-menu"

Controls:

• UP/DOWN navigate menu items
• LEFT/RIGHT change selected value
• BUTTON activate SaveExit
• CANCEL save and exit immediately