auto-sync 2026-06-24 18:00

03-Architecture-Hardware/.~lock.watchdog-LISTA-DE-COMPRAS-ES.xlsx#

@@ -0,0 +1 @@
+,focused-serene-brahmagupta,claude,24.06.2026 21:09,file:///sessions/focused-serene-brahmagupta/.config/libreoffice/4;

03-Architecture-Hardware/.~lock.watchdog-protoboard-BOM-3boards.xlsx#

@@ -0,0 +1 @@
+,focused-serene-brahmagupta,claude,24.06.2026 21:03,file:///sessions/focused-serene-brahmagupta/.config/libreoffice/4;

03-Architecture-Hardware/BOM-master.md

@@ -34,7 +34,7 @@ status: Active
 | 11 | Headers F 6/8/10-pin | 2.54 mm | 1ea | 10 | board interconnect |
 | 12 | **5 V supply** | **Mean Well SD-15B-05** (18–36 V→5 V, 3 A) | 1 | 300 | ✅ industrial — keep |
 | 13 | Boost / charger | Adafruit **PowerBoost 1000C** (2465) | 1 | 400 | battery path — review |
-| 14 | **Ignition cond.** | DFRobot **DFR1015** buck | 1 | 106 | 24 V ign → Blackpill PA5 |
+| 14 | **Ignition cond.** | DFRobot **DFR1015** buck | 1 | 106 | **v3: ON-BOARD** — GX16 pin 3 = raw ignition (12–24 V) → DFR1015 → PA5 (digital) |
 | 15 | **Battery** | Hyvel **18650 1S4P** (FG-0889, 3.6 V) | 1 | 204 | ⚠ charge ≤45 °C — decide |
 | 16 | Status LED + holder | Steren 5 mm + bezel | 1 | 3 | PB0 path |
 | 17 | Resistor | 1.5 kΩ (use TBC — see watchdog-schematic) | 1 | 1 | verify value |
@@ -80,16 +80,16 @@ savings at 24 V — sourcing decision lives here in `09_`.
 |---|---|---|---|
 | Inner case | **ASA — keep** (adequate); optional metal / plate-mount | conduction, not material, is the lever | RCA, hardware-brief §2b |
 | Internal wiring | **Dupont/hand-wire → PCB + locking connectors** | vibration intermittents | hardware-brief §4 |
-| Battery path | **PowerBoost 1000C + 18650 → decide:** drop / LiFePO4 / supercap | heat + safety; do we need parked tracking? | hardware-brief §6.1 |
+| Battery path | **RESOLVED 2026-06-24: keep 18650 1S4P + LTC4040 charger** (NTC temp-qualified; MCU cuts charge when cell hot). Proto stand-in = TP4056+MT3608 | runtime needed → fix the *charging*, not the cell | `watchdog-electrical-design-state.md` |
 | Fuse | **verify the 2 A blade** vs measured worst-case + inrush | client's "under-rated fuse" | RCA H5 |
 | Watchdog discretes | **2N3904/IRF9540N/pull-ups → integrated load switch on PCB** | fewer parts, defined turn-on | hardware-brief §4 |
 | SIM | micro-SIM buried → **front-panel SIM or MFF2 eSIM** | maintainability | hardware-brief §6.2 |
-| Thermal | **conduct heat to metal plate / sunshade; NO internal fan** | sealed-box physics | hardware-brief §2b |
+| Thermal | **v3.0: waterproof duct + Blackpill smart fan** (active managed) + conduct to plate / sunshade | a *ducted* fan removes heat without breaking IP67 | hardware-brief §2b, RCA |
 
 ## Open Questions
 
 - [ ] Confirm the **installed blade-fuse value** (2 A may be under-rated for LTE inrush).
-- [ ] Battery decision (drop vs LiFePO4 vs supercap) — blocks the PCB power section.
+- [x] ~~Battery decision (drop vs LiFePO4 vs supercap)~~ → **RESOLVED 2026-06-24: 1S4P + LTC4040** (NTC temp-qualified charging). Now: **confirm the pack Ah** (label says 40 Ah — suspect; 4× 18650 ≈ 10–14 Ah) → it sizes the charge current + the LTC4040 safety timer.
 - [ ] Lock supplier per line (Helgen vs alternate quote) for the August batch.
 
 ## Related
@@ -97,3 +97,5 @@ savings at 24 V — sourcing decision lives here in `09_`.
 - [[CLAUDE|Master Index]] · [[03-Architecture-Hardware/cabinet-electrical-bom|Cabinet BOM detail]] ·
   [[03-Architecture-Hardware/hardware-respec-and-pcb-brief|Hardware re-spec + PCB brief]] ·
   [[03-Architecture-Hardware/watchdog-schematic|Watchdog schematic]]
+- **[[03-Architecture-Hardware/watchdog-electrical-design-state|Electrical design state & assumptions (CANONICAL)]]** ·
+  `watchdog-protoboard-BOM-3boards.xlsx` + `watchdog-LISTA-DE-COMPRAS-ES.xlsx` (proto BOMs, 3 boards)

03-Architecture-Hardware/kicad/.history

@@ -1 +1 @@
-Subproject commit cf90f5fad3a5740b0c24752c559287b4771d72cc
+Subproject commit 45eed65860823dd11044a02baa4c92a173d5e284

03-Architecture-Hardware/kicad/hbox-watchdog-v3.kicad_pro

@@ -649,7 +649,7 @@
         "uuid": "561403b3-895e-4153-a7be-3876ae930d43"
       }
     ],
-    "used_designators": "",
+    "used_designators": "#PWR1-4",
     "variants": []
   },
   "sheets": [

03-Architecture-Hardware/kicad/hbox-watchdog-v3.svg

@@ -8,7 +8,7 @@
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   version="1.1"
   width="297.0022mm" height="210.0072mm" viewBox="0.0000 0.0000 297.0022 210.0072">
-<title>SVG Image created as hbox-watchdog-v3.svg date 2026-06-24T00:42:37 </title>
+<title>SVG Image created as hbox-watchdog-v3.svg date 2026-06-24T00:45:31 </title>
   <desc>Image generated by Eeschema-SVG </desc>
 <g style="fill:#000000; fill-opacity:1.0000;stroke:#000000; stroke-opacity:1.0000;
 stroke-linecap:round; stroke-linejoin:round;"

03-Architecture-Hardware/watchdog-connections-rationale.md

@@ -10,6 +10,12 @@ against: blackpillrtkcode_v2.ino v2.2 · watchdog-pcb-v3-design.md
 
 # Watchdog Connection List — Justification & Firmware Cross‑Check
 
+> ⚠️ **Current electrical state (2026-06-24): see
+> [[03-Architecture-Hardware/watchdog-electrical-design-state|watchdog-electrical-design-state.md]]
+> (CANONICAL).** The PA5 ignition row's "R9/R10 (÷2)" is **superseded** — there is **no divider**
+> (DFR1015 **on-board** → Rig 100 Ω → D5 BAT54 clamp → PA5 digital). EXT_LED (J1/14) was a real
+> disconnect, now fixed. Reset, 4-LED gauge, power-cutoff, and the LTC4040 battery backup were added.
+
 > Every connection in [[03-Architecture-Hardware/watchdog-connections|`watchdog-connections.xlsx`]]
 > justified — **where it goes, how it's wired, why** — and checked **against the actual
 > firmware** (`blackpillrtkcode_v2.ino` v2.2). This pass found **3 issues to fix before fab**

03-Architecture-Hardware/watchdog-electrical-design-state.md

@@ -0,0 +1,170 @@
+---
+title: Watchdog v3 — Electrical Design State & Assumptions
+tags: [project-drogheda, hardware, watchdog, electrical, assumptions, canonical]
+project: Project Drogheda
+author: Helgen CTO
+date: 2026-06-24
+status: Active — CANONICAL current electrical state (read this first)
+---
+
+# HBOX Watchdog v3 — Electrical Design State & Assumptions
+
+> **Read this to get the electrical context.** It is the single source of truth for the
+> *current* state of the watchdog electrical design — power tree, pin map, the decisions made
+> and why, the bug fixes, what is in the schematic vs. still pending, the prototype approach,
+> and the open items. Supersedes scattered notes. Links: [[watchdog-pcb-v3-design|design doc]] ·
+> [[BOM-master|production BOM]] · `kicad/hbox-watchdog-v3.kicad_sch` (schematic).
+
+---
+
+## 0. Status (2026-06-24)
+
+KiCad schematic `03-Architecture-Hardware/kicad/hbox-watchdog-v3.kicad_sch` — **ERC = 0 errors**
+(only cosmetic off-grid + one `Q_NPN_BCE` symbol-cache warning). Authored via the KiCad MCP;
+renders to PDF/SVG (`kicad-cli` PATH fixed in `claude_desktop_config.json`).
+
+**In the schematic NOW:** MCU (Blackpill J1/J2), MAIN5V/3V3 rails, 24 V reverse-polarity protect
+(Q10 + 15 V Zener DzG), RTK-stack load switch (Q1/Q5), three sense dividers, **on-board DFR1015
+ignition conditioning**, fan driver + dedicated fan buck (U2), I²C temp sensors (SHT40 0x44 +
+TMP102 0x48), status LED, **reset (SW1 on-board + P10 external)**, **4-LED battery gauge**,
+output connectors, PWR_FLAGs.
+
+**Designed but NOT yet wired (next pass):** the **battery-backup power section** (LTC4040 block
++ battery connector + NTC + the P2→MAIN5V re-route) and the **power-cutoff switch**. The LTC4040's
+detailed switching reference circuit (symbol, inductor, program resistors sized to the real pack)
+is a dedicated power-design pass — *not fabricated blind*.
+
+---
+
+## 1. Power tree (current intent)
+
+```
+Cabinet 24 V ─GX16─► Mean Well SD-15B-05 (24→5 V) ─► MAIN5V (board logic rail)
+                                                      ├─► Blackpill 5V (J1/20, J2/18) → 3V3 (on-module LDO)
+                                                      ├─► Load switch (Q5 NPN → Q1 P-FET) → SW_5V → RTK stack
+                                                      └─► [PLANNED] LTC4040 backup ↔ 1S4P cell; boosts to 5 V on power loss
+Cabinet 24 V ─GX16─► Q10 rev-pol P-FET (IRFR5305 + DzG 15 V Zener) ─► U2 fan buck (MP1584) → 5V_FAN → fan
+Machine ignition (12–24 V) ─GX16 pin 3─► DFR1015 (ON-BOARD, →5 V) ─► Rig 100 Ω ─► D5 BAT54 clamp→3V3 / C9 ─► PA5
+[PLANNED] cutoff switch in series with SYS_5V (downstream of the battery merge) → kills vehicle + battery
+```
+
+- **MAIN5V** is the board logic rail. With the LTC4040 inserted, `P2` (vehicle 5 V) feeds the
+  LTC4040 input and the LTC4040 output feeds MAIN5V (so MAIN5V is the *backed-up* rail).
+- **Corrections ride the 4G modem**, not the GNSS — recover a dead link by power-cycling the stack.
+- **Power-off is the safe state**: the RTK stack defaults OFF (gate pull-up) until the MCU asserts.
+
+---
+
+## 2. Pin map — STM32F411 Blackpill (current)
+
+J1 = header P1, J2 = header P2. SWD (PA13/PA14) is **not** on the 2×20 → flash via USB.
+
+| Pin | Net | Function | Notes |
+|---|---|---|---|
+| PA0 | `BAT_SENSE` | ADC ÷2 from battery+ | also feeds the gauge logic |
+| PA1 | `PWR_CTRL` | RTK-stack load-switch enable | HIGH = stack ON |
+| PA2 / PA3 | `GNSS_TX/RX` | USART2 ↔ F9P UART | NMEA |
+| PA4 | `5V_SENSE` | ADC ÷2, vehicle 5 V present | — |
+| PA5 | `IGN_SENSE` | **digital** `INPUT_PULLDOWN` | from DFR1015 via Rig + D5 clamp — **NO ÷2** (Finding 2) |
+| PA6 | `FAN_PWM` | 25 kHz fan PWM | TIM3_CH1 |
+| PA8 | `CHRG_EN` | **[PLANNED]** LTC4040 charge enable/disable | MCU cuts charge when TMP102 reads cell hot |
+| PA9 / PA10 | `USART1` relay | optional NMEA relay | `ENABLE_PHLG_RELAY` default 0 |
+| PB0 | `EXT_LED` | status LED (low-side) | **FIXED 2026-06-24** (was disconnected) |
+| PB6 / PB7 | `I2C1 SCL/SDA` | SHT40 (0x44) + TMP102 (0x48) | 4.7 k pull-ups |
+| PB10 | `FAN_TACH` | fan RPM + stalled-fan fault | EXTI |
+| PB12–PB15 | `BATLED1–4` | **[NEW]** battery gauge bar | firmware-driven from `BAT_SENSE`, 330 Ω + LED each |
+| PC13 | onboard LED | — | WeAct module |
+| NRST | `NRST` | **[NEW]** reset | SW1 (on-board) + P10 (external), both → GND |
+
+---
+
+## 3. Decisions made this session (2026-06-24) + rationale
+
+1. **DFR1015 folded ON-BOARD** (was an external module). **GX16 pin 3 now carries RAW machine
+   ignition (12–24 V), not pre-conditioned 5 V.** The on-board DFR1015 (7.5–30 V in, 5 V out)
+   auto-handles 12 V *and* 24 V machines, drops the external-module dependency, and removes the
+   risk of 24 V reaching the 5 V-rated clamp. Nets: `IGN_24V` (P1/3 → U5 VIN), `IGN_5V`
+   (U5 VOUT → Rig). **Harness implication: feed raw ignition to GX16 pin 3 — not 5 V.**
+2. **Ignition sense topology (confirmed, Finding 2):** PA5 is a *digital* input. Path =
+   DFR1015 5 V → `Rig 100 Ω` series → `IGN_SENSE` → `D5 BAT54` clamp to 3V3 + `C9 100 nF` → PA5.
+   **No ÷2 divider** (a divider drops the logic-high below V_IH).
+3. **Battery backup RE-ADDED** — reverses the old "battery dropped / vehicle-only" (Finding 3).
+   Real trackers carry a cell; we want runtime on a parked machine. Pack = **18650 1S4P**
+   (Hyvel FG-0889, 3.6 V). Charger = **LTC4040** (1S Li-ion/LiFePO4 *battery-backup manager*:
+   switching reverse-buck charger + power-path + 2.5 A boost to 5 V backup + **NTC**). **Safety
+   lever:** NTC on the cell **+** the Blackpill gates charge (`CHRG_EN`) off when TMP102 reads the
+   cell hot — this directly answers the RCA's #1 failure (hot Li-ion swelling/ignition). The
+   charge voltage jumper-selects Li-ion *or* LiFePO4, so a future chemistry change is config, not
+   redesign. **LTC4040 is 1S-only → sufficient for 1S4P.** (Rejected: supercap = last-gasp only;
+   BQ24074 + boost = cheap/available but no LiFePO4 path, linear charge heat.)
+4. **Reset** — on-board button **SW1** + external connector **P10**, both pull `NRST` → GND.
+5. **Battery gauge** — 4 LEDs (D_BAT1–4 = 25/50/75/100 %) on PB12–PB15 via 330 Ω, firmware-driven
+   from `BAT_SENSE` (no gauge IC; reuses spare GPIOs).
+6. **Power cutoff** *(planned)* — external switch in series with the **system 5 V** (downstream of
+   the battery merge) so it kills vehicle **and** battery power.
+
+---
+
+## 4. Bug fixes this session
+
+- **EXT_LED disconnect (real):** J1/14 (PB0) was not on the `EXT_LED` net — a wire ran *through*
+  the pin without terminating, so the MCU couldn't drive the status LED. Fixed →
+  `EXT_LED` = J1/14 · Rled · Q4 gate.
+- **Panel-LED short:** a stray wire bridged `P8` pin 1↔pin 2 (anode↔cathode of the external status
+  LED). Deleted → `LED_A`/`LED_K` clean.
+- **Ground unified:** 4 stray `power:GNDREF` symbols (added during arrangement) → `power:GND`
+  (left as-is they'd have renamed the whole ground net to `GNDREF`). One `GND` net now.
+- Schematic grid-snapped to 1.27 mm; symbol fields (Footprint/Datasheet/Description) hidden so only
+  Reference + Value show.
+
+---
+
+## 5. Prototype approach (3 boards, easy-to-find parts)
+
+- BOMs: `watchdog-protoboard-BOM-3boards.xlsx` (engineering, ≈ MXN 5,341) and
+  `watchdog-LISTA-DE-COMPRAS-ES.xlsx` (plain-Spanish shop list for a non-expert buyer).
+- **Battery backup on proto = module stand-in:** **TP4056** charger + **MT3608** boost + 2× 1N5819
+  OR-ing + 10 k NTC — reproduces charge / power-loss→backup / `BAT_SENSE` / cell-temp so the
+  firmware is fully testable. **The PCB uses the LTC4040.** The one thing the proto can't test
+  exactly is the *temperature-qualified charge cutoff* (LTC4040-only) — validate it in firmware logic.
+- **GNSS + 4G: one F9P + 4G set, shared** across the three watchdog boards (the watchdog logic,
+  sensing, fan/temp, gauge, reset, cutoff and backup all test without them).
+
+---
+
+## 6. Key assumptions / invariants (electrical)
+
+- Backup pack is **1S4P, 3.6 V nominal** (NOT 3S). The "40 Ah" on the label is suspect (4× 18650 ≈
+  10–14 Ah max) — **confirm**; it sets charge current + the LTC4040 safety timer.
+- **GX16 pin 3 = raw machine ignition (12–24 V)** into the on-board DFR1015 (changed this session).
+- **MAIN5V** = board logic rail (from SD-15B-05; backed up via the LTC4040 path once wired).
+- Corrections ride the **4G modem** → recover the link by power-cycling the stack, never a GNSS reset.
+- **Power-off is the safe state**; the load switch defaults OFF until the MCU asserts confidence.
+- **Enclosure is ASA** (not PLA); the thermal liability is the **power components** (battery/boost/
+  modem), not the case. v3.0 thermal = **waterproof duct + Blackpill smart fan** (active managed).
+- No material softening < ~80 °C in the thermal path.
+
+---
+
+## 7. Open items / TODO (electrical)
+
+- [ ] **Wire the battery-backup section** into the schematic: LTC4040 block (U6) + battery connector
+      (BAT+, BAT−, NTC) + the `P2 → LTC4040 → MAIN5V` re-route + `CHRG_EN`/`BAT_SENSE` to the MCU.
+- [ ] **Add the power-cutoff switch** in series with SYS_5V.
+- [ ] **LTC4040 detailed reference design** — symbol, inductor, `RPROG` (charge current sized to
+      the real pack Ah), input-current limit, PFI divider, NTC bias, compensation — then **bench-validate**.
+- [ ] **Confirm the real pack capacity** (the "40 Ah" label).
+- [ ] **Firmware**: gauge-LED driver (PB12–15 from `BAT_SENSE`); `CHRG_EN` cut-charge-when-hot logic
+      (TMP102); reset is hardware-only.
+- [ ] Cosmetic: position the new parts on-grid (clears off-grid warnings).
+
+---
+
+## 8. Pointers
+
+- **Schematic:** `kicad/hbox-watchdog-v3.kicad_sch` (+ `…-schematic.pdf/.svg`).
+- **Design doc:** [[watchdog-pcb-v3-design]] (sub-circuits, pin map, findings).
+- **Connections:** `watchdog-connections.xlsx` + [[watchdog-connections-rationale]].
+- **BOMs:** [[BOM-master]] (production) · `watchdog-protoboard-BOM-3boards.xlsx` +
+  `watchdog-LISTA-DE-COMPRAS-ES.xlsx` (proto) · [[watchdog-protoboard-bringup]] (bench order).
+- **Firmware:** `04-Source-Code/firmware/blackpillrtkcode_v2/` (v2.3) + `docs/PINOUT.md`, `docs/LOGGING-SPEC.md`.

03-Architecture-Hardware/watchdog-pcb-v3-design.md

@@ -9,6 +9,13 @@ supersedes_section: hardware-respec-and-pcb-brief.md §4 (watchdog carrier detai
 
 # HBOX Watchdog Carrier PCB — v3.0 Design (Watchdog + Smart-Fan Thermal)
 
+> ⚠️ **Current electrical state (2026-06-24): see
+> [[03-Architecture-Hardware/watchdog-electrical-design-state|watchdog-electrical-design-state.md]]
+> (CANONICAL).** Since this doc, the DFR1015 folded **on-board** (GX16 pin 3 = raw ignition), the
+> **battery was re-added** (LTC4040 + NTC temp-qualified charging on the 1S4P pack), and **reset +
+> 4-LED gauge + power-cutoff** were added. Where this doc disagrees with the canonical state, the
+> canonical state wins. (Also: 1 fan, not "two" — see the 1-fan update.)
+
 > The production PCB for the STM32F411 watchdog, **expanded** to drive two
 > extraction fans and monitor internal temperature/humidity. This is the
 > schematic-capture spec: every sub-circuit, every value, every part, the pin
@@ -464,7 +471,7 @@ Either way, **v3 ships unchanged** — this experiment only informs a *later* de
       SD-15B-05 powers the MCU; **PA4 senses the vehicle-side 5 V**; P4 = sense-only, battery
       DNP). *If ICAVE needs parked tracking*, fit LiFePO4/supercap on P4 **and move the PA4
       sense tap to the SD-15B-05/P2 (vehicle) node**, not the battery-backed rail.
-- [ ] Confirm the **DFR1015** stays an external module (P1 IGN) or folds on-board later.
+- [x] ~~Confirm the **DFR1015** stays external or folds on-board~~ → **RESOLVED 2026-06-24: folds ON-BOARD.** GX16 pin 3 now carries raw machine ignition (12–24 V) into the on-board DFR1015 → Rig 100 Ω → D5 BAT54 clamp 3V3 → PA5 (digital, no divider).
 - [ ] **Load switch**: discrete (default, sourceable) vs eFuse U1 — verify AP2553 LCSC
       stock at order; otherwise ship discrete.
 

03-Architecture-Hardware/watchdog-protoboard-bringup.md

@@ -118,6 +118,7 @@ The v2.2 firmware reads **I²C SHT40 (0x44) + TMP102 (0x48)**. Whatever you brin
   the derate still triggers, so you can prove the fan path even before the sensor arrives.
 
 ## Related
+- **3-board PROTO BOM (use this for bring-up):** `watchdog-protoboard-BOM-3boards.xlsx` (engineering, ≈MXN 5,341) + `watchdog-LISTA-DE-COMPRAS-ES.xlsx` (plain-Spanish shop list). **v3 adds:** reset (on-board + external), 4-LED battery gauge, power-cutoff switch, and battery backup (proto: TP4056+MT3608+OR-diodes+NTC; PCB: **LTC4040**). Canonical electrical state: [[03-Architecture-Hardware/watchdog-electrical-design-state|watchdog-electrical-design-state.md]].
 - [[03-Architecture-Hardware/watchdog-pcb-v3-bom|v3 BOM (production + bench, xlsx)]] ·
   [[03-Architecture-Hardware/watchdog-pcb-v3-design|v3 design (pin map, sub‑circuits)]] ·
   `04-Source-Code/firmware/blackpillrtkcode_v2/blackpillrtkcode_v2.ino`

CLAUDE.md

@@ -59,6 +59,17 @@ retracted; only **master 21** confirmed). Built **`hbox-log-tools`** (Log Explor
 analyzer + dashboard + manual) and a **Blackpill v2.1 logging spec** to fix observability.
 Canonical: `06-Testing-Validation/2026-06-20_Drogheda_GNSS-Findings-Summary.md`.
 
+**Electrical / PCB (2026-06-24).** Watchdog v3 KiCad schematic
+(`03-Architecture-Hardware/kicad/hbox-watchdog-v3.kicad_sch`, ERC-clean). **DFR1015 folded
+on-board → GX16 pin 3 now carries RAW machine ignition (12–24 V)**, not pre-conditioned 5 V.
+**Battery re-added** with a proper charger — **LTC4040 + NTC temperature-qualified charging** on
+the 1S4P pack; the Blackpill cuts charge when the cell is hot (answers the RCA's #1 failure).
+Added **reset** (on-board + external), a **4-LED battery gauge**, and a **power-cutoff** switch;
+fixed two real schematic bugs (EXT_LED disconnect, panel-LED short). Proto = **3 boards** of
+easy-to-find parts (`watchdog-protoboard-BOM-3boards.xlsx` + Spanish shop list
+`watchdog-LISTA-DE-COMPRAS-ES.xlsx`). **Canonical electrical state →
+`03-Architecture-Hardware/watchdog-electrical-design-state.md` — read first for any electrical context.**
+
 ---
 
 ## 1. System architecture (corrected from the BOM, 2026-06-20)
@@ -86,7 +97,10 @@ Canonical: `06-Testing-Validation/2026-06-20_Drogheda_GNSS-Findings-Summary.md`.
 
 - **Power into HBOX = clean 24 V** from the cabinet (via **GX16-5**). Internal
   **Mean Well SD-15B-05** makes 5 V; **PowerBoost 1000C + 18650** is battery
-  backup; **DFR1015** conditions ignition to the Blackpill.
+  backup; **DFR1015** conditions ignition to the Blackpill. *(This diagram is the field
+  as-built; the **v3 PCB design supersedes the battery + ignition path** — DFR1015 and an
+  **LTC4040** battery-backup charger fold on-board, GX16 pin 3 carries raw ignition. See
+  `03-Architecture-Hardware/watchdog-electrical-design-state.md`.)*
 - **Corrections arrive over the 4G modem** (RTCM3 via NTRIP), not the GNSS — so a
   GNSS reset can't fix a dead link; recover by power-cycling the stack (v2 does).
 - **Watchdog** = STM32F411; see [[03-Architecture-Hardware/watchdog-schematic|watchdog-schematic]].
@@ -130,7 +144,7 @@ these before presenting; if it breaks one, say so and propose the compliant fix.
 | `00-Project-Management` | plan, ethos, hackathon, **financials**, **handover**, client comms, Drive tooling | [[00-Project-Management/PLAN\|PLAN]] · [[00-Project-Management/Engineering-Handover\|Engineering-Handover]] · `ethos.md` · `hackathon-plan.md` · `Financials.md` · `Drive-Upload/` · `client-comms/` |
 | `01-Requirements` | what we build | `SRS.md` · `HBOX-product-spec.md` |
 | `02-Architecture-Software` | backend/software analysis, ADRs | `backend-review.md` |
-| `03-Architecture-Hardware` | HBOX/cabinet, wiring, BOM, **watchdog PCB v3** | `hardware-respec-and-pcb-brief.md` · `cabinet-electrical-bom.md` · `watchdog-schematic.md` · `watchdog-health-telemetry.md` · `firmware-review.md` · `BOM-master.md` · **`watchdog-pcb-v3-design.md`** (schematic spec: +1 fan, +I²C temp/RH) · `watchdog-pcb-v3-bom.xlsx` (proto+production, LCSC) · `watchdog-pcb-v3-kicad-guide.md` (KiCad→JLCPCB) · `watchdog-pcb-v3-blockdiagram.svg` · `watchdog-protoboard-bringup.md` (shop list) · `watchdog-connections.xlsx` (pin/net connection list, PCB+proto) · `watchdog-connections-rationale.md` (per-connection justification + firmware cross-check; flags Q10 Vgs, ignition level, 5V-sense tap) |
+| `03-Architecture-Hardware` | HBOX/cabinet, wiring, BOM, **watchdog PCB v3** | `hardware-respec-and-pcb-brief.md` · `cabinet-electrical-bom.md` · `watchdog-schematic.md` · `watchdog-health-telemetry.md` · `firmware-review.md` · `BOM-master.md` · **`watchdog-pcb-v3-design.md`** (schematic spec: +1 fan, +I²C temp/RH) · `watchdog-pcb-v3-bom.xlsx` (proto+production, LCSC) · `watchdog-pcb-v3-kicad-guide.md` (KiCad→JLCPCB) · `watchdog-pcb-v3-blockdiagram.svg` · `watchdog-protoboard-bringup.md` (shop list) · `watchdog-connections.xlsx` (pin/net connection list, PCB+proto) · `watchdog-connections-rationale.md` (per-connection justification + firmware cross-check; flags Q10 Vgs, ignition level, 5V-sense tap) · **`watchdog-electrical-design-state.md`** (CANONICAL electrical state — read first) · `kicad/hbox-watchdog-v3.kicad_sch` (schematic, ERC-clean) · `watchdog-protoboard-BOM-3boards.xlsx` + `watchdog-LISTA-DE-COMPRAS-ES.xlsx` (proto BOMs) |
 | `04-Source-Code` | firmware + backend repos | `firmware/` (**own git repo `hbox-firmware`**: `blackpillrtkcode_v2/` deploy · `legacy/` v1 · `docs/LOGGING-SPEC.md` v2.1) · `htracker/` · `notifications/` · `rtk-config/` |
 | `05-Analytics-Reports` | SQL views, dashboards (VERONICA/PowerBI), **observability** | `2026-06-22_Drogheda_Manual-Logs-Grafana_v1.0.pdf` (Grafana/Loki log-consultation manual) |
 | `06-Testing-Validation` | RCA, diagnostics, test evidence, **log analysis & tooling** | `RCA-2026-06-field-failures.md` · `remote-diagnostic-protocol.md` · `2026-06-20_Drogheda_Bench-Log-Analysis_v1.0.md` (rev-3) · `2026-06-20_Drogheda_GNSS-Findings-Summary.md` · `log-analysis/` (repo **`hbox-log-tools`**: `log-explorer.html` · `analyze_logs.py` · `build_dashboard.py` · `docs/manual.pdf`) |