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CC2 Device Documentation

Device Views (DVs)

A Device View (DV) is a JSON file that defines everything the device shows on its e‑paper screen: pages, widgets, fonts, and interactions. Each DV is stored in the /dvs/ directory on the device’s USB filesystem and is activated by the allocation process.

How DVs are loaded:

  • The allocdata.json (or unallocdata.json) file lists which DVs to use and maps them to internal names like home, duress, syscfg, etc.
  • A DV can be embedded directly in the allocdata ("src":"inline") or loaded from a local file ("src":"local" → /dvs/<name>.json).

What a DV looks like

Section titled “What a DV looks like”

Every DV follows this skeleton:

{
  "displayName": "Human-readable name",
  "displayIcon": "icon_name",
  "target_size": { "w": 176, "h": 264 },
  "infopages": [
    {
      "id": "1",
      "infowidgets": [ ... ]
    }
  ]
}

Each widget has:

  • type – dynamic (value changes) or static (fixed)
  • interaction – static, dynamic, button, editable
  • value – the initial or fixed value
  • format – text, graphic, bool, number, msglist
  • formatter – how the value is displayed (font, alignment, outlines, etc.)

Where widget data comes from

Section titled “Where widget data comes from”

Not all widget values are hard‑coded. The data source can be identified by the widget’s name and the DV’s documentation:

SourceExample
Static JSONA fixed label like "Config Duress"
Device configvname in the duress DV user data
duress_appMQTTsubj and location in the alerts msglist
Device sensorsBattery gauge, BLE scan results

Key for troubleshooting: A widget that shows a person’s name may get that name from the device’s own data (e.g., duresshome → user_name) or from the portal (e.g., duress → alerts → subj). The individual DV pages explain exactly which source each widget uses.

DV inventory (from a live device)

Section titled “DV inventory (from a live device)”
DV FileCategoryDisplay Name (if known)Page
duress.jsonDuressDuressduress
duresshome.jsonDuressHome (wearer)duresshome
duresstest.jsonDuress(test variant)duresstest
allocated_home.jsonHome screensAllocated Homeallocated-home
unallocated_home.jsonHome screensUnallocated Homeunallocated-home
badge_lock.jsonSystemBadge Lockbadge-lock
emptydv.jsonSystem(empty placeholder)–
syscfg.jsonSystemSystem Configsyscfg
sysctrl.jsonSystemSystem Controlsysctrl
sysfns.jsonSystemSystem Functionssysfns
syshome.jsonSystemSystem Homesyshome
sysinfo.jsonSystemSystem Infosysinfo
syslock.jsonSystemSystem Locksyslock
systest.jsonSystemSystem Testsystest
visite.jsonAppsVisitevisite
wallet.jsonAppsWalletwallet

(Files starting with ._ are macOS resource forks – ignore.)

Working with DVs

Section titled “Working with DVs”
  1. To list installed DVs on a device: Send an fget command for /dvs via MQTT. The device returns a directory listing with all DV files and sizes.
  2. To inspect a specific DV: Read the individual DV page (like duress.mdx) — each page documents every widget, its purpose, and its data source.
  3. To diagnose a portal/device mismatch: Cross‑reference the DV’s documented data source with the portal’s behaviour. For example, if a notification shows the wrong name, check whether the widget’s data comes from the device config or from the portal’s MQTT commands.
Section titled “Related”