WPSD DIY Hotspot
Overview
The DIY WPSD HotSpot is the hand-built DMR hotspot in this lineup — a Raspberry Pi + duplex MMDVM hat + Nextion HMI display + enclosure assembled in April-May 2022 from individually sourced parts, flashed to Pi-Star, and since migrated forward to W0CHP-PiStar-Dash (WPSD). It is the tinker half of the two-hotspot duality: where the SkyBridge Plus is the turnkey appliance, this is the bench-side experimentation platform with full SSH access, a large Nextion display, duplex operation, and upstream-WPSD-nightly currency. This deep dive covers the four-piece hardware stack, the duplex-vs-simplex operating difference, the build-from-SD-card-up configuration workflow, the multi-year config-backup archive, and on-air network use. Migrated from the Scanners project as part of the Scanners/Radios restructure Stage 2 Phase 2 (2026-06-16).
Context
The unit runs as a **duplex** MMDVM (separate TX/RX frequencies, true DMR Tier II two-slot operation) — the hostname progression `pi-star-duplex` → `tjs-duplex` tracks the Pi-Star → WPSD migration. It is partitioned against the SkyBridge Plus on the same shelf: different frequency, typically a different network (TGIF or cross-mode bridges), so the two hotspots don't desense each other and each dashboard stays readable. The DIY build wins on cost (~USD 50-80 BOM), customisability (the Nextion 3.5" display vs the SkyBridge's OLED), SSH-level control, and faster upstream feature access. The `projects/wpsd-hotspot/` payload (kept on disk, gitignored) carries the WPSD config exports, the Nextion HMI layouts, the April-2022 build photos, and — importantly — do-not-publish Wi-Fi credentials.
