Connectors & Wiring¶
Overview¶
The regulator has four RJ45 jacks arranged as two dual-jack connectors — RJ5 (left) and RJ3 (right). Each jack gets its own Cat6 ethernet cable, cut from a standard patch cable (buy two, cut each in half — four cables total).
| Cable | Connector / Port | Destination |
|---|---|---|
| 1 | RJ5 — left port | Alternator area |
| 2 | RJ5 — right port | Battery area |
| 3 | RJ3 — left port | Network electronics (Victron / BMS / NMEA) |
| 4 | RJ3 — right port | Control switches (future) |
Wire colors follow T568A Cat6 standard. Pin numbering is 1–8 per jack.
RJ5 — Left Dual Connector¶
Cable 1 — Alternator area (RJ5 left port)¶
| Pin | Wire Color | Signal | Notes |
|---|---|---|---|
| 1 | Green/White | 3.3 V | Power for temp sensor |
| 2 | Green | GND | Shared GND — temp sensor, current sensor power and signal |
| 3 | Orange/White | TEMP-DQ | DS18B20 temp sensor data (after 100 Ω series + 1 nF filter — see DS18B20 Interface) |
| 4 | Blue | TACHIN | Alternator stator tap for RPM. Ground this pin if not using RPM to prevent noise pickup. |
| 5 | Blue/White | 5 V | Current sensor power |
| 6 | Orange | AIN3 (Xtra) | Spare analog input — thermistor or alternate sensor |
| 7 | Brown/White | AIN1 (Alt current) | Alternator current sensor signal |
| 8 | Brown | TACHOUT | Tachometer drive output from ESP32 (level-shifted square wave for dashboard tachometer). Audit 2026-05-23: previously documented as GND — that was wrong, the signal on this pin is the tachometer output via R2 series resistor. |
Cable 2 — Battery area (RJ5 right port)¶
| Pin | Wire Color | Signal | Notes |
|---|---|---|---|
| 9 | Green/White | IN+ INA228 | Battery shunt + |
| 10 | Green | IN− INA228 | Battery shunt − |
| 11 | Orange/White | AIN0 / VBUS INA228 | Battery + voltage measurement |
| 12 | Blue | AIN3 (Xtra) | Spare analog input — thermistor |
| 13 | Blue/White | AIN2 (LM2907OUT) | Do not connect — reference point only |
| 14 | Orange | 5 V | Thermistor power |
| 15 | Brown/White | UART RX1 | Victron VeDirect Rx (GPIO 7) |
| 16 | Brown | BMSLogic | BMS enable signal — accepts 5–28 V (GPIO 42) |
RJ3 — Right Dual Connector¶
Cable 3 — Network electronics area (RJ3 left port)¶
Victron, BMS, NMEA2000, and other logic-level control signals.
| Pin | Wire Color | Signal | GPIO | Notes |
|---|---|---|---|---|
| 1 | Green/White | UART RX1 | 7 | Victron VeDirect Rx — alternate connection point |
| 2 | Green | 5 V | — | Convenient 5 V source for pins 3, 5, 7 inputs |
| 3 | Orange/White | EXTRA_OPTICAL_GPIO1 | 8 | Apply 5–28 V — logic not yet defined |
| 4 | Blue | UART RX2 | 6 | NMEA0183 Rx |
| 5 | Blue/White | HIGH/LOW | 39 | Apply 5–28 V to force faster charging mode |
| 6 | Orange | IGNITION | 1 | Connect to engine ignition — wakes WiFi and all functions |
| 7 | Brown/White | FORCEFLOAT | 40 | Apply 5–28 V to force maintain-voltage mode (zero net battery current) |
| 8 | Brown | GPIO0 | — | Programming mode only — short to GND. See note below. |
Cable 4 — Control switches (RJ3 right port)¶
All active-low inputs. Ground the relevant pin (via a switch to pin 16) to trigger the function. (Switch panel not yet developed.)
| Pin | Wire Color | Signal | GPIO | Notes |
|---|---|---|---|---|
| 9 | Green/White | FactoryReset | 41 | Ground to restore factory firmware. User settings and WiFi config are retained. |
| 10 | Green | WakeFromDeepSleep | 5 | Ground to wake from deep sleep (ignition also does this) |
| 11 | Orange/White | WifiReset | 45 | Ground to reset WiFi credentials and serve WiFi config page |
| 12 | Blue | AP/ClientMode | 46 | Ground to enter AP (hotspot) mode instead of connecting to ship's WiFi |
| 13 | Blue/White | RESET | — | Ground to reboot the regulator |
| 14 | Orange | ON/OFF | — | Ground to cut alternator field output — hardware, not software-dependent |
| 15 | Brown/White | Buzzer + | 21 | 5 V output for external buzzer — 750 mA max |
| 16 | Brown | GND | — | Shared return for all pins 9–15 |
Programming Mode¶
Optional — ESP32 programs without these connections
The ESP32 can typically be programmed over USB without pulling GPIO0 low. These pins are provided as a fallback.
To force programming mode: short RJ3 pin 8 (GPIO0, brown wire) to GND before powering up, then upload firmware via USB. To reboot into normal operation: release the short and ground RJ3 pin 13 (RESET) momentarily, or power-cycle the board.