---
title: HBOX Watchdog v3 PROD — Harness / Connector Pinout
project: Project Drogheda
date: 2026-07-04
tags: [project-drogheda, hardware, harness, pinout]
---

# HBOX Watchdog v3 PROD — Harness / Connector Pinout

Auto-generated from the PCB netlist (placement-independent). `GND` = the board ground plane (In1.Cu); its full pad list is omitted. Power nets flagged for wire gauge.

| Conn | Function | Pins |
|---|---|---|
| **P1** | GX16-5 | 5 |
| **P2** | 5V-IN-SD15B05 | 2 |
| **P3** | RTK2B-UART1 | 4 |
| **P4** | BATT-1S4P+NTC | 3 |
| **P5** | TEMP_PROBE | 4 |
| **P6** | FAN | 4 |
| **P8** | PANEL_LED | 2 |
| **P10** | RESET-EXT | 2 |
| **P11** | CUTOFF-SW | 2 |
| **P12** | NTC-HOTSPOT | 2 |
| **P13** | MODO-B-UPLINK | 3 |

## P1 — GX16-5

| Pin | Net | Ties to |
|---|---|---|
| 1 | `24V_IN` ⚡power | D10.1, Q10.2 |
| 2 | `GND` | board ground plane |
| 3 | `IGN_IN` | Rig.1 |
| 4 | — | *(no net)* |
| 5 | — | *(no net)* |

## P2 — 5V-IN-SD15B05

| Pin | Net | Ties to |
|---|---|---|
| 1 | `VEH5V` ⚡power | C30.1, C31.1, JP1.2, R51.1, R55.1, R7.1, RS1.1, U6.6, U6.16 |
| 2 | `GND` | board ground plane |

## P3 — RTK2B-UART1

| Pin | Net | Ties to |
|---|---|---|
| 1 | `SW_5V` ⚡power | C3.1, C40.1, MOD1.5, Q1.3, U7.2, U7.7 |
| 2 | `GND` | board ground plane |
| 3 | `GNSS_TX` | J1.8, MOD1.16 |
| 4 | `GNSS_RX` | J1.9, MOD1.15 |

## P4 — BATT-1S4P+NTC

| Pin | Net | Ties to |
|---|---|---|
| 1 | `BAT_PLUS` ⚡power | C35.1, L6.2, R5.1, U6.23 |
| 2 | `GND` | board ground plane |
| 3 | `NTC` | R55.2, U6.17 |

## P5 — TEMP_PROBE

| Pin | Net | Ties to |
|---|---|---|
| 1 | `3V3` ⚡power | Cu3.1, Cu4.1, D5.1, J1.18, J2.20, MOD1.2, R3.1, R30.1, R31.1, R42.1, R57.1, R58.1, Rdfu.2, Rtp.1, U3.3, U4.5 |
| 2 | `GND` | board ground plane |
| 3 | `I2C_SDA` | J2.15, R31.2, U3.1, U4.6 |
| 4 | `I2C_SCL` | J2.14, R30.2, U3.2, U4.1 |

## P6 — FAN

| Pin | Net | Ties to |
|---|---|---|
| 1 | `5V_FAN` ⚡power | C23.1, D2.1, JP1.1, L2.2, R20.1 |
| 2 | `FAN_RET` | D2.2, Q2.3 |
| 3 | `GND` | board ground plane |
| 4 | `FAN_TACH_RAW` | Rts.1 |

## P8 — PANEL_LED

| Pin | Net | Ties to |
|---|---|---|
| 1 | `LED_A` | D1.2, R3.2 |
| 2 | `LED_K` | D1.1, Q4.3 |

## P10 — RESET-EXT

| Pin | Net | Ties to |
|---|---|---|
| 1 | `NRST` | J1.5, SW1.1 |
| 2 | `GND` | board ground plane |

## P11 — CUTOFF-SW

| Pin | Net | Ties to |
|---|---|---|
| 1 | `MAIN5V` ⚡power | C32.1, C33.1, C34.1, JP2.1, JP3.3, JP4.1, Q7.1, Q7.2, Q7.3, R53.1, U6.1, U6.24 |
| 2 | `SYS5V` ⚡power | D6.1, F1.1, J1.20, J2.18, K1.2, R2.2 |

## P12 — NTC-HOTSPOT

| Pin | Net | Ties to |
|---|---|---|
| 1 | `NTC_TEMP` | C24.1, J1.15, R42.2 |
| 2 | `GND` | board ground plane |

## P13 — MODO-B-UPLINK

| Pin | Net | Ties to |
|---|---|---|
| 1 | `USART1_RX` | H3.2, J2.7, K1.1, MOD1.23, Rdfu.1 |
| 2 | `DIN_4G` | J7.3, K1.5, K1.6 |
| 3 | `GND` | board ground plane |