S9 Energy
Signal Nine Sentinel Inc.
Connecting
Solar · Battery · Load

Energy monitor

Keep your usual Wi-Fi

Connect the monitor to your home network for everyday use.

Monitor settings

Changing the measurement point or direction starts new totals. Renaming alone keeps them.

Connection

This device

Choose a connection

Use Bluetooth
Bluetooth PIN

Use six digits. Changing the PIN removes saved Bluetooth pairings. Reconnect with your new PIN. Wi-Fi settings and energy totals stay saved.

Forgot a changed PIN? See Help → Bluetooth PIN recovery.

Home Wi-Fi optional

Add your home network here. You can keep watching over Bluetooth while it connects.

Use your home Wi-Fi

Your phone or PC can stay on its usual network.

Choose your network

Use a 2.4 GHz home network. Networks that need a browser sign-in or a work/school username are not supported.

Can’t reach the monitor?

Join the monitor’s S9-Energy Wi-Fi using password S9Energy2026, then open http://192.168.4.1.

The monitor’s own Wi-Fi stays available for setup and recovery. If your phone reports “No internet”, stay connected while setting up.

Help & support

Signal Nine Sentinel Inc.

Help with your energy monitor

If something isn’t working, email us with a short description of the problem.

Email supportsupport@s9sentinel.com

Getting connected

  1. Power your monitor with USB.
  2. Tap Connect my monitor. Choose S9-Energy from the Bluetooth popup and enter the six-digit PIN if asked. The starting PIN is 123456. Use Chrome on Android or Chrome/Edge on a PC with Bluetooth. Open the page in the browser itself if you scanned the QR inside another app.
  3. Your readings appear. Keep your phone on its usual Wi-Fi. No account is needed.
  4. Want home Wi-Fi? Open Connection, choose your 2.4 GHz network and enter its password. Keep watching over Bluetooth, or tap Use Wi-Fi once both devices are on that network.

Bookmark this page or use Add to Home screen for a shortcut. Internet is needed to load the QR webpage; an open Bluetooth page and the monitor’s local Wi-Fi dashboard can read without internet. The monitor keeps measuring while the page is closed.

Connect without Bluetooth
  1. Join S9-Energy-xxxxxx Wi-Fi. Password: S9Energy2026. Stay connected if your phone says “No internet”.
  2. Open http://192.168.4.1. If it does not open, use the router address shown in your phone’s Wi-Fi details.
  3. In Connection, add your home network. Rejoin that network on your phone and tap Use Wi-Fi.

Already set up? Use the remembered monitor under “Already connected to home Wi-Fi?” on the start screen, or enter its local address. The browser changes address when switching between Bluetooth and local Wi-Fi.

Bluetooth PIN recovery

Every new monitor starts with 123456. Change it in Connection → Bluetooth PIN. A saved pairing may reconnect without asking for the PIN again.

After updating your monitor or changing the PIN, you may need to forget S9-Energy in your phone/PC Bluetooth settings before pairing again.

Forgot your changed PIN? You can recover it by connecting the monitor to your computer with USB.

USB recovery instructionsConnect the monitor by USB. In a serial terminal set to 115200, send BT PIN followed by Enter to read the PIN. To restore 123456, send BT RESET and restart. Your energy totals and home Wi-Fi settings stay saved.
Wiring · XIAO ESP32-S3
XIAOEvery INA226
3V3VCC / VS
GNDGND
D4 / GPIO5SDA
D5 / GPIO6SCL

ALERT can stay unconnected. All sensors share these four wires and must have different addresses. Use the board’s labels, not a guessed terminal order.

The shunt goes in series with the positive wire. Never put IN+ and IN− across a battery. Connect the measured circuit’s negative to sensor GND. Power down before changing wiring.

Adding a second sensor

One INA226 can measure solar input; another can measure signed battery current. Give them distinct addresses using their A0/A1 hardware straps. A1=GND and A0=GND gives 0x40; A1=GND and A0=VCC gives 0x41. Jumper layouts vary—check your module before soldering.

Your monitor finds measuring boards automatically. Each board needs its own address. Disconnect power before adding a board; it appears after restart or a scan.

Solar and battery direction

Solar: panel positive → IN+; IN− → charger solar positive. Positive power means harvested power.

Battery: charger/system battery-positive node → IN+; IN− → battery positive. Positive current charges the battery; negative current discharges it. All battery-positive current must pass through the shunt.

VBUS must sense the intended positive node, typically IN−. Some modules connect it internally; others expose a separate VBUS terminal. Never apply panel voltage to VCC. For bench tests, power the ESP32 separately by USB so its Wi-Fi consumption does not inflate your camera measurements.

History and saved totals

The graph shows the latest hour, averaged every 10 seconds. It starts again when the monitor restarts. Energy totals are saved on your monitor every 5 minutes. Use Save now before disconnecting power; an abrupt power loss can lose up to 5 minutes of totals. Measurement pauses if a measuring board disconnects. Missing readings appear as gaps. This app does not measure battery percentage or charger efficiency from a single sensor.

Reset totals?