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Connecting to the Regulator

After wiring is complete, this page covers everything between "power applied" and "dashboard on your screen." No USB-C cable required — you can do the whole thing from a phone, tablet, or laptop.

There are two things to decide: how the regulator gets on a network, and whether you use a web browser or the app. Read the short explainer first, then jump to your situation.

Background reading:

Find your situation and jump straight to it:

Your boat How the regulator connects
Has WiFi — router, Starlink, or marine WiFi Your boat's network (Client mode) — recommended, full Cloud Features
No router, but you carry a phone Your phone's hotspot (Client mode) — full Cloud Features whenever the hotspot is on
No network at all — off-grid or bench The regulator's own hotspot — local control only, no Cloud Features

Also on this page: Override wires · Common WiFi gotchas

How the regulator reaches a network

This is the single most important thing to understand before connecting. The regulator gets onto a network in one of three ways. The first two are both Client mode — the regulator joins someone else's WiFi and gets internet, so all Cloud Features work. The third is a local-only fallback.

1. Your boat's network — best when you have it

The regulator joins your boat's WiFi (a router, Starlink, or marine WiFi system), exactly like a laptop joining your home router. It gets internet, so all Cloud Features work — history logging, leaderboards, fleet stats, weather data, and over-the-air firmware updates. It's reachable at http://alternator.local from any phone or laptop on that same network. If you have a fixed network on the boat, use it.

2. Your phone's hotspot — full Cloud Features without a router

No boat router? Turn on your phone's Personal Hotspot and the regulator joins that as its network. This is still Client mode: the regulator reaches the internet through your phone's cellular connection, so all Cloud Features work whenever the hotspot is on. Local monitoring and control work even with zero cell signal — the cellular link only adds the cloud half. This is the recommended setup for boats without a fixed network. Full walkthrough: Using your phone's hotspot as the network.

3. The regulator's own hotspot — local-only last resort

The regulator broadcasts its own WiFi network (ALTERNATOR_WIFI) and you connect your phone directly to it. There is no internet behind it, so this is a true fallback.

The regulator's own hotspot has no Cloud Features

When the regulator runs its own hotspot it has no internet, so all Cloud Features are lost: no history, no leaderboards, no fleet stats, no weather, and no over-the-air updates. It works fine for local monitoring and control, but if you have any way onto a real network — a boat router, or even your phone's hotspot (option 2) — use that instead.

First-time setup is its own thing

Out of the box, before you've told it anything, the regulator starts in a temporary setup state — it broadcasts ALTERNATOR_WIFI only to show you the configuration page, and the alternator stays off until setup is done. That's covered in First-time setup.

Browser or iOS app

Web browser — works on anything (iPhone, Android, tablet, Mac, Windows, Linux), nothing to install, and is required for first-time setup. You type http://alternator.local (or the regulator's IP). Use any browser you like.

iOS app ("Xengineering Regulator") — the recommended day-to-day experience on an iPhone or iPad. The app bundles the dashboard on the phone so it feels faster, and it finds the regulator for you (no typing the address) — including over a phone hotspot, where it falls back to scanning the small hotspot network if the alternator.local name doesn't answer. It is not used for first-time setup — set the regulator up in a browser first, then switch to the app. Distributed via the App Store / TestFlight. An Android app is on the roadmap; Android users use a browser for now.

First-time setup

Always done in a browser — a brand-new regulator has no idea what your boat's WiFi is, so it starts in setup mode and shows a configuration page. Do this once in a browser; the app cannot do first-time setup.

1. Power up

Apply 12 / 24 / 48 V to BAT+ / BAT−. The on-board LED begins blinking. Within ~20 seconds the regulator's setup network — ALTERNATOR_WIFI — appears in the WiFi list of any nearby device.

2. Join the setup network and open the config page

Setting Default
Network ALTERNATOR_WIFI
Password alternator123
  • iPhone / iPad: Settings → Wi-Fi → ALTERNATOR_WIFI → password alternator123. iOS warns about no internet — tap Use Without Internet. A setup browser sheet pops up automatically with the WiFi Configuration page. If it doesn't, open Safari → http://192.168.4.1.
  • Android: Settings → Network & Internet → ALTERNATOR_WIFI → alternator123. Tap the "Sign in to network" notification, or open Chrome → http://192.168.4.1.
  • Mac: WiFi menu → ALTERNATOR_WIFI → alternator123. macOS opens a captive window automatically, or browse to http://192.168.4.1.
  • Windows / Linux: join ALTERNATOR_WIFI normally, then open a browser to http://192.168.4.1 (usually no auto-popup).

3. Enter your settings

The WiFi Configuration page has two blocks:

Ship's WiFi (Client mode — strongly recommended):

  • Ship's WiFi Name (SSID) — your boat network name, exactly as shown (case-sensitive).
  • Ship's WiFi Password — that network's password.

Fill these in. This is what enables Cloud Features and alternator.local access. Almost everyone should use this.

No fixed boat network? Enter your phone's hotspot here

You don't need a router to get Cloud Features. Turn on your phone's Personal Hotspot (see the phone-side settings first — 2.4 GHz and a plain-text name matter), then type the hotspot's name and password into these two Ship's WiFi fields. The regulator will join your hotspot on every boot and give you full Cloud Features whenever it's on.

Ensure your WiFi uses WPA2-PSK

Set your router's security mode to WPA2-PSK (shown as "WPA2-Personal" in most router settings); WPA2/WPA3 mixed mode also works. Phone hotspots already use WPA2 by default. Networks the regulator cannot join: anything weaker than WPA2 (WEP, original WPA), enterprise networks with a username + login, and 5 GHz-only networks — the radio is 2.4 GHz only, so on a dual-band router make sure the 2.4 GHz band is enabled.

Hotspot name / password (optional):

  • New Alt. Reg. Hotspot Name — leave blank for ALTERNATOR_WIFI, or choose your own.
  • New Alt. Reg. Hotspot Password — leave blank for alternator123, or set your own (8+ characters).

Always set a custom hotspot password

The factory alternator123 is publicly documented — anyone in WiFi range could join and see your dashboard. Set a custom hotspot password even if you use Client mode normally, since the regulator's own hotspot is your emergency fallback.

Tap Save Configuration. The regulator reboots (~3 s).

No fixed boat network at all? You have two good options before falling back to the regulator's own hotspot: enter your phone's Personal Hotspot in the Ship's WiFi fields (recommended — it keeps Cloud Features; see Using your phone's hotspot), or run the regulator on its own hotspot via the override wire (local only, no Cloud Features). Saving with the Ship's WiFi fields blank just returns the regulator to this setup page on reboot — the alternator stays off for safety. Set a custom hotspot password here first either way.

4. Where to go next

After the dashboard loads, continue to Initial Settings for the in-dashboard walkthrough.

Using your phone's hotspot as the network

Client mode for boats without a router — full Cloud Features whenever your hotspot is on.

Your phone's Personal Hotspot acts as the boat's network: the phone is the gateway, the regulator joins as a client, and any device on the hotspot (including that same phone) reaches the dashboard. Because the hotspot carries your cellular data, the cloud half of the system works whenever you have signal; the local dashboard and full alternator control work even with no signal at all.

Some budget prepaid plans block the regulator

A few low-cost prepaid carriers restrict their Personal Hotspot and will drop the regulator seconds after it connects — even when it's the only device on the hotspot, and even though your phone and laptop join that same hotspot without trouble. Visible is one we've confirmed does this. There is nothing to fix on the regulator; the carrier is refusing it. So if the regulator connects for a moment and then keeps dropping on your phone's hotspot, this is almost certainly why — and the fix is either a standard (postpaid) plan, or a small travel router in client mode between the hotspot and the regulator: the router joins the hotspot as one ordinary device, and the regulator connects to the router. A travel router also gives the regulator a stable address, which sidesteps the mDNS quirks below.

Set up the hotspot (once)

  1. Turn on Personal Hotspot. iPhone: Settings → Personal Hotspot → Allow Others to Join.
  2. Use the 2.4 GHz band. iPhone: turn Maximize Compatibility on. The regulator's radio is 2.4 GHz only — with an iPhone hotspot left on its default 5 GHz, the regulator can't see it.
  3. Use a plain-text hotspot name. Rename your phone (iPhone: Settings → General → About → Name) to letters, numbers, and spaces only. An apostrophe or special character in the name (e.g. "Joe's iPhone") can stop the regulator from joining.
  4. Enter the hotspot into the regulator once. In first-time setup, type the hotspot's name and password into the Ship's WiFi fields. From then on the regulator joins your hotspot automatically on every boot.

Leave the hotspot on to keep the regulator present

A phone hotspot switches itself off after about 90 seconds with no devices connected. Because the regulator stays joined, it keeps the hotspot alive on its own — but if you turn the hotspot off, the regulator drops until you turn it back on.

Reaching the dashboard over a hotspot

An iPhone hotspot hands out addresses in a tiny fixed range — the phone is 172.20.10.1 and devices get 172.20.10.2 through 172.20.10.14. Two things differ from a normal router: the name alternator.local is less reliable over a hotspot, and the regulator's address can change each time the hotspot restarts. How you find it depends on your device:

  • iPhone / iPad app — nothing to do. The app tries alternator.local, and if that doesn't answer it quickly probes the hotspot's address range and reconnects on its own, including after the address changes. Grant Local Network permission on first launch, or it can't scan.
  • Mac or PC (browser) — point the browser at the regulator. Try http://alternator.local first; if it doesn't load, find the address. A Mac can scan its own hotspot from Terminal:
for i in $(seq 2 14); do curl -s -m1 http://172.20.10.$i/identify | grep -q '"device":"xregulator"' && echo "regulator at http://172.20.10.$i"; done

Then open the http://172.20.10.X address it prints. (A browser can't scan the network on its own — that's why you run the one-liner or use the app.) - Phone browser (Android, or an iPhone without the app) — use http://alternator.local; if it doesn't resolve, find the regulator's address in your phone's hotspot Connected Devices list and browse to it.

Load the dashboard over http, straight from the regulator

Don't open the hosted website over https:// and expect it to reach the regulator — a browser blocks a secure page from talking to a plain-http local device. Always go directly to http://alternator.local or http://172.20.10.X.

Android and plain browsers can't auto-scan

Only the iOS app scans the hotspot for you. On Android or a desktop browser you either use alternator.local or find the address yourself (the Terminal one-liner above, or your phone's connected-devices list). An Android app is on the roadmap.

Cloud Features follow your cell signal

Everything local — the dashboard, charging control, live data — works with no cell signal at all. The cloud half (history upload, weather, remote updates) needs a working cellular connection; on a weak signal it catches up when the connection improves.

Day-to-day connecting

For a phone hotspot, read Using your phone's hotspot above — the sections below cover a fixed boat network and the regulator's own hotspot.

Browser, Client mode

The recommended setup: regulator on your boat WiFi (or your phone's hotspot), you use a browser.

  1. Put your phone / laptop on the same network the regulator joined.
  2. Open any browser → http://alternator.local.

What to expect: the full dashboard with all Cloud Features working (history, leaderboards, fleet stats, weather, over-the-air updates). Reachable from every device on that network.

Use http, not https

Type http://alternator.local. If the browser auto-prefixes https://, the page won't load.

alternator.local doesn't resolve? Some routers block mDNS / Bonjour, and it is less reliable over a phone hotspot. Open your router's device list (or, on a hotspot, your phone's Connected Devices), find the host named alternator, note its IP, and browse to http://<that-IP> (e.g. http://192.168.1.47, or http://172.20.10.X on an iPhone hotspot). iPhones, iPads, and Macs resolve alternator.local natively; Windows may need Apple's Bonjour Print Services or just use the IP.

Browser, the regulator's own hotspot

Fallback only — no boat network. Cloud Features are unavailable in this mode.

  1. Make sure the hotspot wire is connected (see Override wires).
  2. Join ALTERNATOR_WIFI (your custom password, or alternator123). If your device prompts about no internet, choose Use Without Internet. If a sign-in / setup sheet appears, you can dismiss it.
  3. Open any browser → http://alternator.local (or http://192.168.4.1, which always works on the regulator's own hotspot).

What to expect: the full dashboard and full alternator control, but no Cloud Features (no history, leaderboards, fleet stats, weather, or remote updates) — there's no internet behind the regulator's own hotspot.

iOS app, Client mode

Recommended app setup: regulator on your boat WiFi or your phone's hotspot.

  1. Set the regulator up in a browser first (above) and confirm the dashboard loads at http://alternator.local.
  2. Put your phone on the boat WiFi, or turn on your Personal Hotspot (the regulator joins it).
  3. Open the Xengineering Regulator app. On first launch, iOS asks for Local Network permission — tap Allow (without it, the app can't find the regulator by name or by scanning a hotspot).

What to expect: the same dashboard, but snappier, and the app finds the regulator automatically — no address to type. Over a phone hotspot it also re-finds the regulator on its own if the address changes. All Cloud Features available.

iOS app, the regulator's own hotspot

Fallback only — no boat network. Cloud Features are unavailable in this mode.

  1. Make sure the hotspot wire is connected (see Override wires).
  2. Join ALTERNATOR_WIFI on the phone (Use Without Internet if asked).
  3. Open the Xengineering Regulator app (grant Local Network permission on first launch).

What to expect: the full local dashboard over the regulator's own hotspot. Cloud Features and the in-app Software Update screen are disabled in this mode — there's no internet to reach them.

Override wires

The override wires live in the RJ3 right-port cable, all active-low: touch the wire to pin 16 (brown wire / GND). The boot overrides (pins 9, 11, 12) are sampled at the moment of power-up — ground, power on, release. The wake wire (pin 10) works at any time. A switch panel that exposes these as labeled toggles is in development; for now they are bare wires.

Pin Wire color What it does
9 Orange/White Boot the factory firmware (recovery if an update bricked it)
10 Orange Wake wire — 5 minutes of WiFi + dashboard with the engine off (works any time, not just at boot — see Operating Modes & Power)
11 Green/White Re-show the setup page with default credentials (lost WiFi password)
12 Blue Regulator's own hotspot — run on the regulator's own WiFi
13 Blue/White Hardware reset

See Data Cables & Pinout → Cable 4 for the full pinout.

The regulator's own hotspot (pin 12, Blue)

Ground pin 12 (Blue) to pin 16 (GND) at boot. The regulator skips the ship-WiFi join and brings up its own hotspot (using your custom SSID/password if you set one). Full alternator operation and the full local dashboard, but — as covered above — no Cloud Features. Dashboard at http://alternator.local or http://192.168.4.1.

No boat network? A phone hotspot beats leaving this wire grounded.

You can leave pin 12 grounded for permanent local-only operation (twisting the two wires together is fine, and a manual toggle lets you pick ship-WiFi vs. the regulator's hotspot without reaching behind the dashboard; a labeled switch panel is on the roadmap). But this gives up history, leaderboards, weather, and remote updates. If you carry a phone, running the regulator on your phone's hotspot keeps all of that — leave pin 12 alone and enter the hotspot as your Ship's WiFi instead.

Re-show the setup page (pin 11, Green/White)

Forgot the ship-WiFi password, changed marinas, or lost your custom hotspot password? Ground pin 11 (Green/White) at boot. The setup page returns with default credentials (ALTERNATOR_WIFI / alternator123) regardless of what you customized. Enter new credentials and save.

This recovers WiFi passwords only. The dashboard settings password is a separate thing with no on-device reset — see Forgotten passwords.

Alternator output is disabled while pin 11 is grounded

This is a safety lockout. Remove the short after the regulator boots into setup mode, finish reconfiguring, then reboot.

Factory firmware (pin 9, Orange/White)

If an update bricks the device (dashboard won't load, boot loops), ground pin 9 (Orange/White) at boot to run the read-only factory firmware. Once the dashboard is back, go to Cloud → Firmware to roll back or clear the bad update, then remove the short and reboot.

Common WiFi gotchas

Reconnecting after first-time setup. When the regulator reboots onto your boat WiFi, ALTERNATOR_WIFI disappears and your phone falls back to cellular or a known network. Manually rejoin the boat WiFi before opening the dashboard — iOS won't do it for you because alternator.local isn't a saved network name.

Over a phone hotspot, the address changes. Each time the hotspot restarts the regulator can come back at a different 172.20.10.X. The iOS app re-finds it automatically; in a browser, re-run the Terminal one-liner or check Connected Devices rather than trusting a bookmarked IP.

Captive sheet (iOS) disappears before you finish typing. During setup, iOS times out the captive sheet after 60–90 s. Open Safari → http://192.168.4.1 for the same page with no time limit.

Auto-fill suggests the wrong password. iOS / Chrome keychain may auto-fill a different network's password into the Ship WiFi Password field. Tap No Thanks and type it from memory.

iPhone keeps switching back to cellular. Any time you're on a WiFi with no internet (the regulator's own hotspot, or the setup network), iOS prefers cellular for data. The local connection to the regulator still works; just make sure you're joined to the right network.

Multiple regulators on one boat. alternator.local collides if two regulators are on the same network. Use each device's IP address directly until a custom-hostname feature is added.

Regulator never joins the boat WiFi. Check the router's security mode — the regulator needs WPA2-PSK ("WPA2-Personal"; WPA2/WPA3 mixed is fine). WEP, original WPA, and enterprise (username + login) networks won't work. Also confirm the network has a 2.4 GHz band — the regulator can't see 5 GHz-only networks. On a phone hotspot, that means Maximize Compatibility must be on.

Cross-references