Seeed’s $39.90 e-paper dashboard swaps Wi-Fi for Bluetooth and a two-year estimate
Encryption arrives switched off, and Home Assistant needs a connectable Bluetooth path to reach the little screen.
A home dashboard that can go a long time without meeting a charger has a useful party trick: sitting there, doing very little. Seeed’s compact OpenDisplay kit pairs a low-power Bluetooth link with an e-paper picture, and its battery estimate assumes the screen doesn’t need a new assignment every second.
The 4.26-inch Mono Kit guide describes an assembled 800-by-480 black-and-white display with a 2,000 mAh battery and preinstalled firmware. The maker’s store lists it at $39.90. A case comes with it, so the first job is sending an image rather than finding a box with approximately the right holes.
Seeed estimates up to about two years between charges at roughly 15-minute updates. That is a schedule-dependent estimate, with temperature, image size, refresh choices, and frequency affecting reality. A headline battery figure has finally brought its calendar along (about time).
The kit uses Bluetooth Low Energy only. A browser can send an image, or Home Assistant can supply content, but something within range has to make that connection. Removing Wi-Fi from the display doesn’t remove the need for a route to the information.
| Choice | Display and color | Connection that decides placement |
|---|---|---|
| OpenDisplay Mono Kit | 4.26-inch monochrome | Bluetooth Low Energy only |
| OpenDisplay Color Kit | 7.3-inch six-color panel | Bluetooth Low Energy only |
| reTerminal E1001 | 7.5-inch monochrome | Wi-Fi plus Bluetooth hardware |
| reTerminal E1002 | 7.3-inch six-color panel | Wi-Fi plus Bluetooth hardware |
The reTerminal family table supplies those alternative hardware choices. The chart leaves battery promises out because different update schedules would turn a tidy row into a misleading endurance contest. Size, color, and connectivity already give a buyer useful differences.
Browser compatibility is another practical boundary. Seeed supports Chrome and Edge on desktop or Android and points iPhone and iPad users toward Bluefy. Firefox isn’t supported. A wireless display can still care rather deeply which browser is asking it to do something, just without a cable to blame.
For Home Assistant, the guide calls for a host Bluetooth adapter or an ESPHome proxy capable of active connections. It specifically excludes Shelly BLE proxies for this job. A nearby device with Bluetooth in its name cannot necessarily perform the needed operation, much as owning a phone doesn’t make every call a conference call.
The kit also ships with encryption off. The guide explains switching it to locked mode through the toolbox and recovering the key from the boot screen. That setting belongs in setup, particularly for a screen placed somewhere other people can approach. Low power is not a security policy.
A slowly changing schedule, household status, or room summary could fit this design well. A rapidly changing feed would spend more time and battery refreshing, so the information’s useful update interval should drive the decision. Whether your chosen wall is still reliably within Bluetooth range remains a placement test the specification cannot perform.