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Hardware Overview

This page is the map of the board: what the subsystems are and how they connect. Every subsystem named here has its own page carrying the authoritative specifications — where a number matters, follow the link. If this page and a detail page ever disagree, the detail page wins.

Architecture

The regulator is built around an ESP32-S3 microcontroller. Hardware was selected for ultra-low power consumption, wide voltage range (nominal 12 V, 24 V, 36 V, and 48 V systems), and robust protection for harsh marine and automotive environments.

Power Chain

Battery (4.2–65 V) ──► TPS48000-Q1 ──► VIN_2-60 ──► LMR36510 ──► 5V_LMR ──┐
                       (protection)    (protected         (buck, 1 A)         │
                                        rail to                               ├──► TPS2116 ──► 5 V system rail ──┐
                                        field drive                           │     (power               │      │
                                        & buck)                               │      mux)                │      │
                                                                              │                          │      ├──► TLV62569 ──► 3.3 V ──► ESP32-S3 + peripherals
USB-C (J19) 5 V ──► VBUS_USB_ISOLATED ──────────────────────────────────────┘                          │      │     (buck, 2 A)
                                                                                                          │      │
                                                                                                          │      └──► MT3608 ──► 12 V boost ──► LM5109A ──► Q3 ──► alternator field
                                                                                                          │           (5→12 V, only when field PWM enabled)
                                                                                                          │
                                                                                                          └──► LM2907, TPS2553 buzzer switch, SN74LVC1T45 5 V side

The stages, in order:

  • Input protection (TPS48000-Q1) — reverse polarity, overvoltage, overcurrent, and undervoltage lockout on everything downstream. Thresholds, fault timing, and retry behavior: Input Protection.
  • Main buck (LMR36510) — the sole step-down stage from battery to 5 V; the 3.3 V rail is derived from the 5 V system rail through a second cascaded buck (TLV62569). Rails, loads, capacitor placement, and the measured power-draw table: Switching Power Supply.
  • Power mux (TPS2116) — selects automatically between battery-derived 5 V and USB-C 5 V; no jumper or firmware control. On V9, connect one power source at a time: USB-C.
  • Field-drive boost (MT3608 → LM5109A → Q3) — the 12 V gate-drive rail exists only while the field is being driven. Blocks, jumper configurations, and the P/N-type paths: Alternator Field Drive.
  • CAN-side buck (MPM3610) — a separate supply on the boat-ground side of the NMEA2000 isolation barrier: NMEA2K.

Processing Core

An ESP32-S3 module (dual-core, 16 MB flash + 8 MB PSRAM, WiFi, native USB) runs everything. Why this part, its power pins, the full GPIO allocation table, and the boot/recovery straps: ESP32 Controller.

Measurement

  • Analog front end — an ADS1115 16-bit ADC behind TLV9154 unity-gain buffers measures four channels: battery voltage, alternator current, engine RPM (via an LM2907 frequency-to-voltage converter on the stator tap), and an optional analog temperature input. Per-channel circuits, ranges, protection, and the RPM chain analysis: Analog Inputs.
  • Battery monitor — an INA228 with an external shunt provides the precision battery voltage and current the control and protection loops act on, including a hardware overvoltage alert that can cut the field with no firmware involvement: BatteryV and Current Monitor.
  • Sensors — the clamp-on Hall current sensor (Current Sensor), the alternator temperature options (Temperature Sensors), the on-board barometric pressure and board-temperature sensor (Baro and Temp Sensor), and the 6-axis IMU (6-Axis IMU).

Digital I/O

  • Inputs — two circuit styles: optocoupler inputs for on/off voltage signals (ignition, BMS, force-float) and ground-style inputs for switches. Circuits, activation ranges, and ESD analysis: Digital Inputs.
  • Buzzer output — a current-limited high-side switch with flyback protection for an external alarm buzzer or small relay: Warning Buzzer.

Communications

  • NMEA2000 — a galvanically isolated CAN interface (ISO1050 transceiver with its own isolated supply and selectable termination): NMEA2K. The firmware both listens and transmits; transmit is off by default and is enabled per-message under Setup → Integrations → NMEA 2000.
  • NMEA0183 and Victron VE.Direct — two serial inputs behind a shared optocoupler protection and level-shift stage (input tolerance and fault protection, not galvanic isolation): NMEA0183, Victron VeDirect, and the circuit itself in UART Input Protection.

Protection

Protection is layered: the TPS48000-Q1 input stage guards the whole board, TVS devices sit on the power inputs and high-voltage signals, exposed I/O carries ESD protection, analog inputs are RC-filtered, and the INA228's hardware overvoltage alert provides a firmware-independent field cut. The authoritative numbers live on Input Protection and each subsystem's own page.

PCB and Components

Four-layer board with wide traces on the high-current paths, thermal vias under the power parts, and marine-grade conformal coating (Conformal Coating). Components are industrial temperature range, with automotive-grade parts in the protection circuits. Mechanical design and mounting: Enclosure.

Development and Programming

The ESP32-S3's native USB comes out on the USB-C connector — programming needs no USB-to-serial converter, just manual boot control (GPIO0 + reset). Connector wiring, ESD protection, and power-source rules: USB-C.

System Connections

A complete installation connects: