VX EV ONE Mini OBU

Identify VX Main

Connect Main to Mini by USB

This connection layout is for the VX Main and OBU Mini shown in this guide. Match the connector labels before following it; enclosure openings may be arranged differently.

Connection route: Main USB1 → USB data cable → Mini USB-C.

Main connector identification. USB1 is the Type-C socket farther from the micro-HDMI socket. USB0 is the Type-C socket nearer micro-HDMI. Use the printed USB1 and USB0 labels to identify them rather than the installed unit’s orientation.

1. Keep the system off while arranging the connections.
2. Identify USB1 on Main. On the reference board, this is the Type-C socket farther from micro-HDMI.
3. Connect USB1 to the Mini’s native USB-C socket using a cable that supports data. If using a USB-C host/OTG adapter on Main, connect a USB-A-to-USB-C data cable from the adapter to Mini.
4. Connect the approved Main power lead to USB0, the Type-C socket nearer micro-HDMI, then power the system on.
5. On Mini, open Settings → Connections → Pair Main. Wait for USB CONNECTED or USB MAIN CONNECTED.
6. Then check the separate OBU connection and consent. A working USB link to Main does not by itself mean the OBU is connected.

The standard Mini board in this guide has one native Type-C socket. Its UART pins and battery connectors are not the USB connection to Main. If your Mini has two USB sockets, identify its hardware variant before choosing a port.

If Mini powers up but never reports USB CONNECTED, check for a charge-only cable, an unsuitable adapter, a loose plug, or connection to the wrong Main socket. Use a known data cable and check again before changing Bluetooth pairings.

Use the printed USB0 and USB1 connector labels on VX Main. The connection layout above reserves USB0 for Main power.

Register the Bluetooth address of VX Main, which connects to the OBU. This is a first-time setup step before OBU pairing.

Watch Part 1 LTA website registration

Watch the VX Audio registration video on YouTube. The same video is available on the OBU Mini product page.

View the Part 1 video above.

Find the correct Bluetooth address

1. Power Main and Mini and allow Mini to connect to Main.
2. On Mini, open Settings → Device → Firmware.
3. Find the line labelled MAIN BT and copy the full address, including the colons. A Bluetooth address has six pairs of letters or numbers, such as AA:BB:CC:DD:EE:FF. This is a format example only.
4. If MAIN BT shows --, restore the Mini-to-Main connection before continuing. If your firmware does not show MAIN BT, obtain the address for your specific Main from your installer.

Register the address on OneMotoring

1. Open LTA OneMotoring ERP digital services and sign in with Singpass.
2. Open Register Smartphone for OBU. If the portal first shows Manage On-Board Unit (OBU), open it to find the registration service.
3. Check that you are registering against the intended vehicle and OBU.
4. Enter a recognisable device name, for example VX Main.
5. Enter the exact MAIN BT address copied from Mini.
6. Select Save, then OK when prompted. Check that the saved entry contains the correct address.

The portal uses the term “Smartphone” for this registration service. For this VX installation, use the Main Bluetooth address identified above.

Allow the new registration to take effect

LTA instructs users to wait approximately 45 minutes after adding a new device before pairing with the OBU. Allow this initial registration period before attempting first-time pairing.

The initial registration wait is separate from the everyday startup times in section 4.

Complete LTA registration and allow the initial registration period before pairing. Keep Main connected to Mini.

Connect the Mini to Main

1. Open Settings → Connections → Pair Main.
2. For Bluetooth setup, tap SCAN FOR MAIN.
3. Check the discovered Main identity or address against your intended unit.
4. Tap CONFIRM PAIR and wait for the result.

If the screen shows USB CONNECTED, Main is already connected by USB. The pairing control reports that connection instead of starting a Bluetooth scan; a saved Bluetooth backup may remain available.

Pair the OBU through Main

1. Ensure Main is connected. Open Settings → Connections → Pair OBU.
2. Tap SCAN FOR OBU.
3. Check the discovered OBU identity, then tap PAIR OBU.
4. When a pairing code appears, check it against the OBU prompt and tap CONFIRM CODE only when it matches. Complete any confirmation requested by the OBU.
5. Wait for a paired result. Check Settings → Device → OBU number to confirm the identity.

Use TRY AGAIN after a reported error. PAIR ANOTHER starts a new pairing search; use it only when you intend to change the OBU.

Choose OBU data consent

Open Settings → Device → Consent. Connect Main, read the text, then scroll upward to the choices.

• ACCEPT allows access to the described OBU data for display, spoken alerts, and diagnostic logs.
• DECLINE keeps OBU data access off.
• ABOUT & LICENCES opens the accompanying information.

You can revisit this page to change your choice. Consent does not switch vehicle payment on or off. Wait for the consent status to confirm the choice.

Start normal operation

OBU connection time depends on how the system is powered. With 24-hour wiring that keeps the system continuously powered, OBU Mini connects to the vehicle’s OBU within 1 minute. When powered from a cigarette-lighter socket or another USB-C power source, allow up to 4 minutes after switching the power on for the system to start and connect to the OBU.

These times apply to a system whose pairing and consent setup is complete, with the vehicle’s OBU available. Wait for OBU CONNECTED before relying on live OBU information.

1. Power the installed VX Main and Mini using their supplied vehicle connections.
2. Allow the Mini to start and establish its connection to Main. A searching or waiting message means live OBU data is not yet available.
3. Read the OBU data consent screen and make your choice.
4. Before relying on the display, check that it shows OBU CONNECTED, the correct OBU identity, and a confirmed payment state.
5. Use Normal mode for everyday operation. Leave any screen marked DEMO / SAMPLE DATA before using the Mini with live vehicle information.

A saved pairing identifies a device; it does not by itself confirm that live OBU information is currently being received.

Touch controls and main screens

Swipe left to move forward through the four main pages: Home → Speed → Trip → Settings → Home. Swipe right to move in the opposite direction. The page dots show your position.

• Tap a menu item or button to open it.
• BACK returns to the parent menu.
• Home button returns directly to the Home screen.
• Sliders change a value by dragging the control.
• Consent text can be scrolled upward to reach the choices.

Card insertion, removal, payment deductions, and road events may temporarily show a message or animation. A deduction can show the deducted amount and the updated balance when those values are received.

Standby and wake

In Normal mode only, the Mini can turn its screen off after the OBU disconnects and the Mini remains inactive for five minutes. This is eligible only after a real paired OBU connection has worked during the current startup. A saved pairing alone does not start the timer.

Touch the screen or move the device to wake it; a renewed live OBU connection also wakes it. The first touch wakes the screen without activating an underlying control. Release your finger, then tap again to operate a control.

Standby turns the display off to reduce power consumption while communication continues. It does not change payment or consent. Setup, consent, or a motion-sensor fault can keep the display awake.

Standby remains disabled in all Demo modes, including Driving demo and LTA display. Simulated demo data never qualifies the Mini for standby.

The screen captures below show where to find the controls. Values and connection messages in these examples are illustrative.

For firmware service, record the version first and follow the update instructions supplied for your installation. Keep power connected during an update and use a firmware file approved for your Mini.

Availability depends on your installation. These instructions apply only to versions supplied with payment on/off control. The Self Install option listed as “Without payment on off function” does not include that function.

Use the payment control

Payment controls must be enabled under Settings → Alerts → PAYMENT CONTROLS. Main must be connected and OBU data consent accepted.

1. Read the current payment status on Home.
2. Tap the payment button to request a change between on and off.
3. Wait for the confirmed status. A tap sends a request; the system must receive a result.
4. When payment is confirmed off, the Mini displays an off countdown of up to 60 seconds. Check that PAYMENT ON is confirmed when you need payment enabled again.

UNCONFIRMED or PAYMENT NOT CONFIRMED means the Mini cannot confirm the requested state. Check Main, the OBU, and the card before retrying. Do not treat a countdown ending or a balance disappearing as proof that payment is on.

Turning off the PAYMENT CONTROLS setting disables the Mini’s payment controls. It is not a command to switch vehicle payment off.

Use voice commands

1. Say “Hi OBU”, “Hello OBU”, or “Hey OBU”. OBU may be spoken as the letters O B U.
2. Wait for the listening response.
3. Say “Payment off” or “Turn payment off”; alternatively, say “Payment on” or “Turn payment on”.
4. Wait for confirmation and check the displayed result.

If recognition is unreliable, open Settings → Sound → Microphone, adjust sensitivity, and tap SAVE & RESTART. Allow the Mini to restart before trying again.

Open Settings → Demo and choose Driving demo or LTA display. The Mini restarts to enter the selected mode. A DEMO / SAMPLE DATA badge identifies simulated information.

Demo balances, speeds, deductions, and messages are sample data. After EXIT and restart, wait for live connections and confirmed status before relying on the displayed information. If MODE NOT SAVED - RETRY or RETRY appears, repeat the selection and verify that the mode actually changes.

For support, provide the firmware version and Mini Bluetooth address from Device → Firmware, the OBU number, the exact message shown, and the steps that led to the problem.

Website and setup video: VX Audio OBU Mini product page.