Setup guide

First-time setup

This is the whole journey, start to finish — download the app, register your phone with LTA, then pair your OBU and your Gantry Display in the car. Registration takes a couple of minutes, and the in-car part a few more. It's all one-time: after this, Gantry reconnects to your OBU and display automatically every time you drive.

What you'll need

Have these ready before you start:

  • An iPhone running iOS 18 or later — the Gantry app is iPhone-only for now, and the display works only with the app.
  • A car with Singapore's next-generation ERP 2.0 On-Board Unit (OBU). The old first-generation IU isn't supported, and neither is the one-piece motorcycle OBU.
  • Your Gantry Display unit. Not ordered yet? Reserve one here.
  • A USB-C cable and power source — any standard one works. The display doesn't come with a cable or a mount, so you can place it wherever suits your car.
  • Your Singpass login, to register your phone at LTA's ERP Online Services.

  1. Download the Gantry app

    Install the free app — Gantry SG on the App Store. It's your setup tool and the bridge between your OBU and the display, so it's worth getting before your collection day.

  2. Register your phone's Bluetooth with LTA

    Before the app can talk to your OBU, your iPhone has to be on the OBU's Bluetooth allow-list. You add it once at LTA's ERP Online Services (Singpass login) — each OBU allows up to five devices. This is only the allow-list; it's not the same as pairing, which you do inside the app in the next steps. Full walk-through: Register your phone with your OBU.

  3. Mount and power the display

    Position the Gantry Display where you can see it at a glance — at eye level works well — and run a USB-C cable to a power source. Mounting is up to you; the app lets you tell the display which way up it sits, so it stays upright however you place it. Once powered, the display shows a pairing QR code and waits for step 5.

  4. In the car, pair your OBU

    Sit in the car with the engine on and give the OBU a moment — it takes about a minute after ignition to boot. In the app, open Set up ▸ Pair your OBU and tap Search for OBU; it scans for about 60 seconds and lists any OBU it finds. Tap yours to pair, then Connect by vehicle number — enter your plate (e.g. SME1111Z) and tap Connect. You only pair once per OBU.

  5. Pair the display by scanning its QR code

    On your phone, open the Display tab, choose Pair a display, tap Scan QR code, and point the camera at the QR code on the display. No cables or codes to type. Once paired, the display reconnects automatically every time.

  6. Confirm everything works

    Back on the app's Home tab you'll see a live preview that mirrors exactly what the display is showing, alongside glance chips for your speed, card balance, and connection status. If the preview matches the display, you're set. From here it's all automatic — get in, and Gantry reconnects to your OBU and display on its own each drive. To learn what every screen and setting does, see everything the Gantry app does.

Stuck at a step? A display showing “Waiting for OBU” for about a minute after you start the car is normal — the OBU is still booting, and Gantry connects the moment it's ready. If it lingers well beyond that, check Bluetooth is on and the app is running. More answers are in the FAQ; and if you're moving the display to a new phone later, see Unpair the display & pair a new phone.
Stuck at any step, or have a question?

Email us — tell us what happened and roughly when. If it's a connection problem, you can send diagnostic logs straight from the app; the support page shows how.

More guides

← Back to Gantry