ENGINEERING · REVISION 0.3 · 11 SEPTEMBER 2026

Real components.
Explicit unknowns.

MOB is being designed around a local AI computer, voice, and an authorized connection to other devices. This is the feasibility baseline, not a production specification.

The component shortlist

Enclosure target: 112 × 72 × 26 mm. Board keep-outs, connectors, antenna zones, battery swelling, cooling, tolerances, and final mass still need a validated CAD stack-up. Renders are not dimensional drawings.

The computer is inside

The intended Linux stack runs a quantized local language model, speech recognition and synthesis, encrypted memory, a browser, a command runner, and the agent harness. Start with a small 3–4B model; larger models depend on measured latency, memory, power, and thermal behavior. NPU acceleration and model support must be confirmed against the vendor BSP.

Wi-Fi or an iPhone hotspot provides internet. Nearby control and call audio are intended Bluetooth uses; the integrated radio must be evaluated before adding a separate module. There is no cellular modem in this baseline. The iOS app provides setup, task review, approvals, and receipts; it is not the model host.

Reach with permission

Tailscale supplies encrypted device networking. Each target also needs an enrolled companion, SSH, an API, or a supported automation adapter and the corresponding OS permissions. It does not unlock every application. iOS actions stay within supported integrations and Shortcuts.

Half a day, honestly budgeted

7 Ah × 3.7 V = 25.9 Wh nominal. Assuming 85% usable energy gives approximately 22 Wh. A 12-hour target therefore requires average system power below 1.83 W.

An illustrative budget is 10 hours at 0.7 W plus 2 hours at 6 W: 19 Wh. None of these power figures has been measured on MOB. Continuous 6 W operation would yield roughly 3.7 hours under the same assumption. Always ready requires a low-power audio path and careful sleep/wake behavior, not continuous full-speed inference.

USB-C is the primary sustained-power path, with a serviceable stowed lead targeted at approximately 100 mm. A 5 W receiver cannot sustain a load above 5 W while adding battery charge. Magnetic mounting and Qi input are design intentions; no MagSafe or Qi2 certification is claimed. A phone does not automatically power the device wirelessly.

Cost before price

The vendor store currently displays $985.58 for its default 8 GB Open-Q 8550CS configuration. That is not a quote for the 16 GB production variant. Volume pricing, licensing, minimum orders and a lower-cost architecture must be established before setting retail price or gross-margin claims.

What we must prove

1. On-device speech → local model → approved action → audible response, with reproducible latency and power traces.
2. Full-duplex iPhone Bluetooth audio, echo cancellation, call-state control, and user takeover during faults.
3. Surface and cell temperatures under charging plus inference, including phone-mounted use.
4. A hardware microphone cutoff plus a separate task-cancel path that remains responsive if the language model stalls. Muting alone does not cancel a running command.
5. Enrolled-device access, revocation, offline receipts, and safe retries without duplicate external actions.
6. Battery sourcing, RF pre-compliance, manufacturing test coverage, and a costed build.

Supplier names identify candidates, not commercial partnerships or endorsements.