One Button to Become the Hub — The Three-Layer Design of xGrid Promote
Promoting a Spoke to Hub doesn't require SSH, a laptop, or command-line skills. Scan a QR code for WiFi, open the PWA, press a button — three steps. Behind it is a Script → API → UI architecture that lets a nurse perform what would otherwise be a sysadmin operation.
Unplug and Go — Hub-Spoke Topology, Role Promotion, and Five-Minute Failover in xGrid
Any Spoke can become a Hub in minutes. A failed Hub gets replaced in five. Every Raspberry Pi ships with the full stack pre-installed — the role is just a config file. This is how xGrid handles topology changes in disconnected environments.