User Manual

NMEA 2000 ⇄ WiFi ⇄ RS485 multiplexer and tactical sailing computer: instrument calibration, true & ground wind, VMG, current, polars and performance — streamed to your phone, plotting apps and the Pixel display — plus battery voltage and state of charge from a Victron SmartShunt over Bluetooth. Руководство на русском → · Download as PDF

1 · What it does

The gateway joins your NMEA 2000 backbone as one more device, listens to everything on the bus, calibrates and smooths the readings, computes tactical data, and streams standard NMEA 0183 sentences over WiFi:

Output	Default port	For
UDP broadcast	2000 (configurable)	Pixel mast display, apps that accept UDP
TCP server	10110 (configurable)	Navionics Boating, OpenCPN, iSailor, qtVlm…
NMEA 2000 out	—	Calibrated values back on the bus as the gateway's own source (opt-in)
RS485 wired 0183	4800/9600/38400 Bd	Legacy instruments — in and/or out

The stream includes position (RMC), COG/SOG, heading (HDM, and HDT whenever true heading exists or can be derived from magnetic variation), apparent and true wind (MWV), ground wind (MWD, computed in the earth frame so it stays correct straight through tacks), depth, boat speed, heel/pitch (XDR) and AIS targets (AIVDM, with vessel names, call signs and dimensions whenever the receiver passes them on).

Battery voltage and state of charge are taken from any charger, BMS or shunt that reports a battery on the bus — or straight from a Victron SmartShunt over Bluetooth, with no cable to the shunt (§13). Fuel and fresh-water tank levels are read too. All of it goes to the web page and to the Cloud Tracks voyage log.

When several devices send the same data (two GPS sources, two depth senders, several battery banks), the gateway arbitrates per data type. Tap a data card on the web page, or use the Sources tab, to pick the winning source yourself.

2 · Installation

NMEA 2000

Connect to a free N2K drop with a standard drop cable. The gateway is powered from the bus — no other wiring is required.

RS485 (optional, for NMEA 0183 instruments)

A 2-wire RS485 terminal (A/B) accepts or drives wired NMEA 0183. The pair is half-duplex: use it as an input, an output, or time-shared both — but not truly simultaneous separate in+out. Configure on the RS485 tab (see §9).

Bluetooth (optional, Victron SmartShunt)

No wiring at all: the gateway reads battery voltage and state of charge from a Victron SmartShunt over Bluetooth. Mount the gateway within a few metres of the shunt, with no metal bulkhead in between, and enter the shunt's address and key on the Setup tab (see §13).

3 · First start & WiFi

1. Power the bus. The gateway starts its own WiFi network can2wifi.
2. Connect your phone/laptop to it and open http://can2wifi.local (or 192.168.4.1).
3. On the Setup tab, scan and join your boat WiFi (up to 3 saved networks; the strongest is used). The setup network returns automatically whenever no saved network is reachable.
4. Device name on the Setup tab changes the address (e.g. myboat → http://myboat.local) and the name of the setup network.

4 · Connecting your apps

Navionics Boating

Menu → Paired devices → add a TCP connection to the gateway's IP, port 10110. Position, AIS and instruments appear on the chart.

OpenCPN

Options → Connections → Add: Network, protocol TCP, address = gateway IP, port 10110. Alternatively UDP, port 2000, address blank (listen).

Pixel display

Nothing to configure — the Pixel listens for the UDP feed on the same network. If another NMEA source (e.g. a WiFi router/gateway) already broadcasts on port 2000, move this gateway to another port (e.g. 2001) in Setup → Status & controls and set the Pixel to the same port.

5 · The web interface

http://can2wifi.local — eight tabs, live over a permanent connection (values update in place, settings apply immediately):

Tab	What's there
Data	Live cards for every received data type; tap a card to see all sources and pick which one wins.
Sources	Every physical sender on the bus, one row each, with the raw values it's transmitting right now — Use locks a sender as the winner (survives reboot); auto returns to freshest-wins. Grouped by wind, heading, speed, GPS, depth, heel, rudder and Battery banks (every charger, BMS or shunt reporting a battery, plus the Bluetooth SmartShunt). Also the N2K output options (transmit SOG as STW).
Tactical	True wind (and where it comes from: bus, log or GPS), ground wind, VMG, current (set/drift), leeway, laylines, wind-shift statistics, gusts, polar targets.
Polar & Sails	Polar upload, polar library, sail wardrobe, self-learning, polar diagram, leeway K.
Calibration	Per-channel smoothing with the per-group → N2K transmit choice; heading offset; wind vane curve; boat-speed (STW) heel grid; live wind dial.
RS485	Wired NMEA 0183 port: enable, baud, routing, diagnostics.
Anchor	Anchor watch: arm/disarm and pick the alert distance. See §12.
Setup	Status & controls (firmware, AIS, ports, N2K out, reboot), WiFi networks, device name, storage health, settings backup, Cloud Tracks pairing, Victron SmartShunt (Bluetooth).

6 · Calibration

All corrections are applied inside the gateway, so every consumer — WiFi apps, the Pixel, the N2K re-broadcast — gets the same calibrated values.

Heading (HDG)

A single offset in degrees for compass installation error.

Wind (AWA / AWS)

The wind-vane curve editor corrects apparent wind angle at multiple points around the circle (mast twist, vane misalignment); wind speed gets a percentage correction. The live wind dial shows raw and final (calibrated + smoothed) values together, so you see exactly what will be transmitted.

Averaging & smoothing

Per channel (AWA, AWS, SOG, COG, HDM, HDT, STW): Mean (even average), Weighted (recent samples count more) or Median (rejects spikes), window up to 30 s. Angles use circular math so 350°/10° average to 0°, not 180°. While N2K out is on, the same table shows a → N2K checkbox per group — Heading, Wind, COG/SOG, STW — choosing which of the gateway's corrected readings are transmitted back onto the bus (§10).

Boat speed (STW) — speed × heel, per tack

The paddlewheel misreads when the boat heels, and differently on each tack. The STW grid corrects it as a percentage over 8 speed rows × 12 heel columns (2°-steps up to 12° where the error changes fastest, then 15–40°), with separate port (red) and starboard (green) tables. Heel comes from the bus (attitude PGN or XDR Roll).

Next to your manual table the gateway builds a recommended table by itself: whenever both GPS speed and paddlewheel speed are available it learns the ratio per cell while you sail. Review it and press Transfer to copy learned cells into the manual table. Reset learning starts over. The Stop learning / Start learning button pauses the self-learning — use it when motoring in waves or towing would pollute the table, and resume when sailing clean. The live row highlights which cell is active right now.

7 · Tactical computer

Value	Needs	Meaning
True wind (TWA/TWS/TWD)	apparent wind + STW (or SOG)	Wind over the water; TWD uses true heading when available. Shown as 0–179° port/starboard.
Ground wind (GWD/GWS)	apparent wind + heading + GPS	Wind over the ground, recomputed continuously in the earth frame — stays correct through tacks and gybes. Sent as MWD.
VMG	true wind + boat speed	Speed made good toward/away from the wind.
Current (set/drift)	heading + STW + GPS	Difference between water track and ground track.
Leeway	heel + STW	K·heel/STW²; set K on the Polar tab (10 is a common start).
Laylines	true wind + polar	Port/starboard layline headings for the optimal upwind/downwind angles.
Wind shift	true wind	Mean direction, current shift and oscillation band over a selectable window (2–30 min), flagged lifted/headed for your tack.
Gusts	true wind	Lull / average / gust wind speed over the last 30 s.
Polar performance	polar + true wind + STW	Target speed at the current wind, your % of target, optimal TWA and target VMG.

Where true wind comes from. By default the gateway calculates true wind itself from apparent wind and boat speed through water. The checkbox Calculate true wind only when it is not on the bus (Tactical tab) changes this: if another instrument already puts true wind on the bus it is used as-is; otherwise the gateway calculates it — from the log, or from GPS speed (SOG) when there is no paddlewheel. The True wind from row shows which one is in use: Bus, Calc: log or Calc: GPS. With N2K out on, apparent and true wind are always transmitted (§10).

8 · Polars & sails

Upload a polar as CSV: first row = TWA list, first column = TWS, cells = target boat speed. Polar library stores several complete polars to switch between. Sail wardrobe: store a polar per sail, tick what's rigged — the gateway combines the enabled sails into the working polar envelope. Learning: while sailing (engine off — it pauses automatically when engine RPM is on the bus), the gateway records your best speed per wind bin; Promote learned turns it into the active polar. The polar diagram plots the active polar with your live point on it. Learning does not wait for a design polar: with none uploaded it records on a default wind grid (4–25 kn, 35–180°), so a boat without published polars still builds its own.

9 · RS485 wired NMEA 0183

Setting	Meaning
Enable + baud	4800 (standard NMEA), 9600 or 38400.
RX → instruments	Sentences received on the wire feed the gateway's data pool (and on to WiFi/N2K).
RX → WiFi relay	Raw received lines are also forwarded to the WiFi outputs unchanged.
TX	The gateway transmits its 0183 sentence set on the wire (for a legacy autopilot/repeater).
Diagnostics	Byte counter + last raw characters — tells wiring problems (0 bytes) from baud/polarity problems (garbage) at a glance.

10 · NMEA 2000 output

With N2K out enabled (Setup tab; off by default), the gateway claims an address and transmits its calibrated heading, wind, boat speed and COG/SOG back onto the bus as its own source. Your MFD can then source-select the gateway instead of the raw sensor. The raw sensor keeps transmitting too — that's how N2K works — so make the selection once on each display.

Option	Where	Meaning
→ N2K per group	Calibration → Averaging & smoothing	Four checkboxes — Heading, Wind (AWA+AWS), COG/SOG, STW — choose which corrected readings go back on the bus. All on by default; untick what you don't want (e.g. keep wind, drop heading).
True wind	always	Apparent and true wind are transmitted whenever N2K out is on, in both the boat-referenced and the water-referenced form, so every display finds the one it expects.
Transmit SOG as STW	Sources tab	Other devices see GPS speed as speed through water — for a boat with a dead or missing paddlewheel.

11 · Cloud Tracks pairing

The gateway can upload your voyage — position, wind, depth, boat speed, battery voltage and state of charge, tank levels and the AIS traffic around you (with vessel names), once a minute while sailing — to the Cloud Tracks web portal: a live map, a full track history with replay, and the anchor watch described next. Pairing is on the Setup tab, Cloud Tracks card:

Setting	Meaning
Upload voyages to pixelmast.com	Master on/off for everything in this card.
Pairing token	From Cloud Tracks → Boats → your boat → Add boat/token. One token, one boat.
AIS capture radius	How far (NM) other vessels' AIS is recorded alongside your track; 0 = capture all.
When stopped	Report cadence while the boat isn't moving: every minute, or a lighter position+weather ping every 10/30 min to save data.
Race mode	1 Hz recording for close replay/analysis of a race, instead of the normal one-per-minute track. Switch it here or on the Cloud Tracks portal — both stay in step, and it turns itself off after five hours stopped.
Automatic updates	Applies a newly published firmware version by itself, but only while the boat has been stopped for several minutes and the anchor watch is off — never mid-passage, never while the anchor watch might need the device.

Full use of the map, replay, alarm zones, races and sharing with crew is covered in the separate Cloud Tracks manual.

12 · Anchor watch

Reports your position to Cloud Tracks once a second while armed, so the drag watch can run on the server — from the Anchor tab on the device, the phone app, or the Cloud Tracks map itself. All three talk to the same watch; the server timestamps every command and always keeps the latest one, so arming from one place and checking from another is safe.

1. Open the Anchor tab.
2. Pick an alert distance: 20 m, 30 m, 50 m, or Custom (20–300 m).
3. Press Arm. The device starts reporting immediately; the server assigns the watch and starts checking your swing against the chosen distance.

Changing the distance while already armed re-arms immediately with the new value — no need to disarm first. Disarming asks for confirmation, since it stops the watch for anyone else watching the same boat.

13 · Battery monitor over Bluetooth (Victron SmartShunt)

If your house bank is measured by a Victron SmartShunt, the gateway can read battery voltage and state of charge straight from it over Bluetooth — no cable to the shunt and no N2K interface. It only listens to the shunt's encrypted Instant Readout broadcasts, once a minute, so nothing is paired: your phone's VictronConnect keeps its own connection, and the bus and WiFi are not affected. Off by default.

1. In VictronConnect open the shunt → Settings → Product info. Make sure Instant readout via Bluetooth is enabled, then open Instant readout details: it shows the shunt's MAC address and encryption key.
2. On the gateway's Setup tab, Victron SmartShunt (Bluetooth) card: tick Read battery voltage & SOC from a SmartShunt, enter the MAC (12 hex characters, colons optional) and the key (32 hex characters), press Save, then Scan now.
3. Within a few seconds the status line reads Last seen N s ago · 12.85 V · 93.0 % · −4.2 A · −18 Ah · RSSI. The shunt now appears on the Data tab and in the voyage log.
4. If an N2K charger or BMS also reports a battery, go to Sources → Battery banks and press Use on Victron SmartShunt (BLE) so the shunt wins. With no other battery source the shunt is used automatically.

Status line	Meaning
No signal from … yet	Nothing heard from that MAC. Check the address, bring the gateway within Bluetooth range (a few metres, no metal bulkhead in between) and press Scan now.
Wrong encryption key	The shunt is heard but the key does not decrypt it — copy the 32-character key from Instant readout details again.
Device answers but is not a battery monitor	The MAC belongs to another Victron product (a charger, a solar controller). Use the SmartShunt's own address.
Auto-disabled this boot	Bluetooth could not start on this boot. Reboot from the Setup tab; if it repeats, contact support.

14 · Firmware updates

Over the air from pixelmast.com: Setup → Status & controls → Update firmware. The device needs boat WiFi with internet. Settings survive updates.

A freshly-installed version is not trusted blindly: the device confirms it booted cleanly (WiFi reachable, the CAN bus initialised, no repeated reboot) before keeping it, and automatically reverts to the previous version if it doesn't — the same safety check runs whether the update was applied by hand here or by Automatic updates (§11).

15 · Storage, backup & factory reset

The Storage card on the Setup tab shows settings-memory usage and data-file space, and turns red if a save ever fails — so nothing is lost silently. Download settings saves a full backup file: calibration, averaging and tack response, polars and the polar library, sails, ports, N2K transmit choices, AIS switch and capture radius, source picks, the Cloud Tracks token, the SmartShunt credentials — everything. Restore from file puts it back — handy before experiments or when moving to a replacement unit.

16 · Troubleshooting

Symptom	Check
No data in the app	Phone/tablet on the same WiFi network? TCP 10110 / UDP port correct? UDP tx enabled on the Setup tab?
No AIS targets	AIS receiver present on the N2K bus? AIS toggle ON (Setup tab)? Targets appear within ~3 minutes.
Web page unreachable	Try http://can2wifi.local (or your device name); if the boat network is down the gateway opens its own setup network.
Wrong source used	Data tab → tap the data card → pick the source.
STW table only learns one tack	Learning needs heel with sign (attitude sensor on the bus) and GPS speed. Check Roll on the Data tab.
No HDT / ground wind	True heading needs either a true-heading source or magnetic variation on the bus (GPS usually sends it). Ground wind additionally needs COG/SOG.
Settings don't survive reboot	Setup → Storage must show free space and no save errors. Update firmware if it shows red.
Anchor watch won't arm / stays "sending"	Needs Cloud Tracks pairing enabled with a valid token (§11) and boat WiFi with internet — check the Cloud Tracks status line on the Setup tab.
Anchor watch shows "lost contact"	The server hasn't heard from the device in a while — check WiFi/internet. It clears itself once reporting resumes.
Battery shows the wrong bank	Sources → Battery banks → Use on the charger, BMS or SmartShunt you want; auto picks the lowest battery instance on the bus.
SmartShunt not seen / wrong key	Read the status line on the Setup card (§13): check range and the MAC, re-copy the 32-character key from VictronConnect, press Scan now.
No true wind on the plotter	N2K out must be ON (Setup); true wind is then sent in both references. If the Tactical tab's True wind from row is empty, the gateway lacks apparent wind or boat speed (log or SOG).

17 · Support

Questions, feature requests: admin@pixelmast.com