Using the Dashcam in Backbuild Miles

A mileage log answers how far you drove. A dashcam answers what happened while you drove it, which is the question that matters on the one day a year when somebody disputes your account of a junction. Backbuild Miles can record while it is already tracking, using the camera you are already carrying. This page covers what it records and what it deliberately does not, where the video lives, how to choose cameras and quality, how the rolling storage limit works, and how to keep the footage around a moment before it is recorded over. After it you will be able to run the dashcam with an accurate idea of what you have and what you do not.

What It Records, and What It Does Not

After this section you will know exactly what the feature does before you turn it on.

Start with the parts people assume wrongly, because the assumptions run in both directions:

It is off by default. Nothing records until you turn it on.
Video only. There is no audio, at all, on either camera. That is a deliberate design choice rather than a missing feature: recording conversation carries legal weight that varies by jurisdiction and by who is in the vehicle, and a mileage app is the wrong place to hand you that problem silently.
The video never leaves your phone. It is not uploaded, not backed up to your account, and not visible to any organization you drive for. It is written to a rolling buffer on the handset and recorded over in turn.
It records while you drive, alongside the tracking you have already set up, rather than as a separate thing to remember to start.

The consequence of the third point is worth stating on its own, because it is the one that catches people out: if you lose the phone, you lose the footage. There is no copy anywhere else. Footage you might actually need should be kept deliberately, which the last section covers.

Turning It On

After this section you will have the dashcam running.

Open Dashcam from the app menu. The first thing the screen needs is camera permission, and until that is granted the master switch stays inactive with a note saying so. Tap Grant camera permission, and your phone will ask whether to allow Backbuild Miles to take pictures and record video. Choosing While using the app is enough.

The screen waits for your phone to confirm the grant and then enables the switch itself. If it tells you the permission has not come through yet, leave the screen and open it again: that is a timing quirk between the app and the operating system rather than a refusal, and your choice has not been lost.

With permission in place, the master switch reads Dashcam is off or Dashcam is on, and it is the single control that starts and stops everything below it.

Choosing Cameras

After this section you will know which cameras your phone can actually use, and why it may be only one.

Two cameras are useful for different reasons. The back camera faces out through the windscreen and records the road, which is what a dispute is usually about. The front camera faces the cabin, which matters if you carry passengers and want a record of what happened inside the vehicle.

Whether your phone can record both at once is not a preference, it is a hardware fact, and the app asks the phone rather than guessing. Three things can happen:

Your phone supports both at once. The screen says so and offers front and back together, front only, or back only.
Your phone cannot. The screen says so plainly and offers one camera or the other, so you make the trade deliberately.
It has not been confirmed yet. Some phones cannot be asked until later in the session. Until the answer is known, only one camera can be chosen.

That last case is worth understanding rather than working around. The alternative would be to let you pick both, record only one, and leave you believing you had cabin footage you never had. A restriction you can see beats a recording you cannot trust.

Resolution and the Storage Limit

After this section you will be able to trade picture quality against how far back your footage reaches.

Resolution runs from SD through HD and Full HD to 4K. These are not free choices: at a fixed storage limit, every step up buys detail and spends time. Full HD is the sensible default for reading a number plate at a sane distance; 4K is worth it only if you have the space to keep a useful window at that quality.

The storage limit has two halves, and whichever is reached first wins. The defaults are one hour and 20 GB. Past that point the oldest footage is recorded over continuously, which is what makes it a dashcam rather than an archive.

The screen shows how much is currently stored, per camera, so you can see what your settings actually produce rather than estimating. Check it after a few days of ordinary driving: if an hour of footage is using far less than your size limit, you can afford more time or more quality, and if it is hitting the size limit early then your real window is shorter than the hour you asked for.

Keeping a Moment

After this section you will be able to save footage before the buffer records over it.

A rolling buffer means the thing you want is on a timer from the moment it happens. The keep button, the camera icon in the trip view, exists for exactly that: press it and the footage around that moment is copied into a kept folder, where the rolling limit does not reach it.

How much it saves is up to you: this screen sets how many minutes before and how many after the press are included. The defaults are five and five. Before matters more than people expect, because you press the button after you realise something happened, not as it happens.

The habit worth building is to press it at the time rather than at the end of the day. By the end of a shift the footage may already be gone, and no setting on this screen can bring it back.

Common Questions

Does the dashcam record sound?

No. There is no audio on either camera, by design. If you need an audio record of something, that is a decision to make deliberately with a tool meant for it, and with the law where you drive in mind.

Can my employer or a client see this footage?

No. The video stays on your phone and is never uploaded. Assigning a trip to an organization sends that organization mileage, not video.

Why can I only choose one camera?

Because your phone either cannot record both at once, or has not yet confirmed that it can. The screen tells you which of the two it is.

How far back does my footage go?

Until the first of your two limits is reached, so it depends on your resolution as much as your settings. The screen shows what is actually stored, which is the number to trust over any estimate.

I lost my phone. Can I recover the video?

No. Nothing is uploaded, so there is no copy to recover. That is the cost of the privacy guarantee, and it is worth knowing before you rely on the footage rather than after.

Does the dashcam use more battery?

Yes, appreciably, and more at higher resolutions and with two cameras. Run it on a charger for a long shift, the same as you would any dedicated dashcam.