AV Institute · Week 3Touchpanel & UI Design
Lesson
Error Messages, Startup/Shutdown Behavior, User Workflows & Consistency
Est. 55 minCompetency: Design error states and consistent workflows.
Learning objectives
- Design clear, non-alarming error messages.
- Define startup and shutdown UX.
- Map user workflows to screens.
- Enforce consistency across the panel.
Vocabulary
- Error state
- A UI condition telling the user something failed and what to do.
- Workflow
- A sequence of screens/actions to complete a task.
- Consistency
- Same control = same look and behavior everywhere.
Lesson content
Errors happen. A good panel says what failed in plain language, offers a next step, and never alarms the user. 'Display did not respond — tap Retry' beats 'ERR_0x42.'
Error messages
- Plain language; no codes as the first thing the user sees.
- State the problem and one action ('Retry,' 'Call support').
- Do not blame the user.
- Keep the panel usable after an error — do not freeze.
Startup and shutdown UX
- 1Startup shows progress ('Starting room…') and resolves to Home when ready.
- 2Shutdown asks for confirmation, then shows progress, then returns to Welcome.
- 3If startup fails, show which step and offer Retry.
Workflows and consistency
- Map each common task to a screen path and walk it yourself.
- Use the same button style for the same action on every screen.
- Keep colors meaningful: one accent for the primary action, dim for unavailable.
Field caution
A panel that freezes on error teaches users to reboot it by pulling power — which can damage displays and corrupt sessions. Always leave the panel responsive, even in error states.
Worked example
Startup workflow: tap Start → 'Starting room…' → display warms → Home appears with 'Room ready.' If the display does not answer: 'Display not responding. Retry / Call support.' The panel stays usable; the user is not stranded.
Implementation checklist
- ✓Errors in plain language with an action.
- ✓Startup/shutdown show progress and confirm.
- ✓Each task maps to a clear screen path.
- ✓Same control = same look/behavior everywhere.
- ✓Panel stays usable after errors.
Downloadable study guide
study-guide.txtcopy-paste ready
01. Errors: plain language, one action, no blame, panel stays usable. 02. Startup shows progress → Home; shutdown confirms → progress → Welcome. 03. Map tasks to screen paths; enforce consistency. 04. Never freeze the panel on error.