Questions people ask before trying it

Does it survive rain and a drop?

Unknown, and we will not pretend otherwise. The Xteink X4 is a consumer e-reader with no IP rating, and nobody here has tested one wet or dropped. Treat it as a device that needs a case or a bar bag in the wet. If that is a deal breaker for you today, it should be.

What happens when Bluetooth drops in the middle of a ride?

The map stays exactly as it was: e-ink holds the last picture with no power, so you keep the frame you were reading. The status strip shows the link as gone. Buttons still work, so you can pan and zoom around the ground already on the card. When the phone comes back, the app reconnects on its own, nothing tapped, and the dot picks up again.

One thing is missing and it matters: there is no fix age on screen. The header shows the current time rather than the time of the last position, so a dot that is twenty minutes old looks as current as one from a second ago. That was a deliberate call and it is written down as a cost. A staleness marker is a small change, not a rewrite, and nobody has ridden long enough with it yet to say how badly it bites.

Does it do anything with no phone at all?

Yes, as a map, no, as a position. It opens at the last fix it remembers and draws the area from tiles on the SD card, and you can pan and zoom with the buttons like a paper map that happens to have a marker on the last place it saw you. What it cannot do is follow you: the GPS fix comes from the phone over Bluetooth, because these readers have no GNSS receiver of their own. That is hardware, not a setting.

So it is not standalone. Why build it that way?

Because the phone is not the problem, the phone on the bars is. The pocket is where a phone is good at its job: it has the GNSS chip, the data connection and the battery you can charge anywhere. Duplicating all three in the thing bolted to the handlebar buys a second device to charge and a second GNSS to lose under trees.

Does it need mobile data?

Only to bring new ground in. A square already on the card draws with the phone in airplane mode and no signal for a hundred kilometres. Riding onto ground nobody has built yet is a request: the reader asks, the phone fetches, the tile server builds the area in about twenty seconds. Both of the data spending features, that fetch and the check for out-of-date squares, are off until you switch them on, because it is your data plan.

How long does a charge last?

Two multi hour runs on the device, map screen up and a phone connected, averaged 35.6 mA and 24.0 mA. On the X4's 650 mAh cell that is roughly 18 to 27 hours of use. We quote 10 h+ publicly because those were riding days rather than a controlled bench test. Both figures come from battery percentage slope on a ride, not from an inline meter, so treat them as a range and not a spec. Holding a picture costs nothing: the power goes into changing it.

Can I read it at night?

Not on the X4. A reflective panel needs light, the same as paper, and the X4 has no frontlight. The X4 Pro does have one in hardware, confirmed by the SDK's own maintainers, but there is no ExplorInk build for that device yet and the app never turns the light on. Today this is a daylight device, and the honest version of the plan is that night comes with the X4 Pro build.

Does it work in the cold?

Not measured, so here is what is known instead. E-ink panels of this class are specified from 0 to 50 °C, and below freezing they get slower and ghost more. The effect is sluggishness, not damage, and it reverses when the panel warms. Nobody has put an X4 in frost and timed a refresh, which is the cheapest missing measurement in the project.

Is there a subscription?

No, and there will never be one for reading a map. The firmware and the phone app are MIT licensed and public, and the maps are OpenStreetMap, so there is no region to unlock. Building and hosting tiles does cost money every month: if a paid tier ever appears it covers that, priority builds and hosted access, never the software on your device and never a square already on your card.

Will it tell me where to turn?

No. There is no voice, no rerouting and no turn prompt. You get the map, your position, your route drawn on it, and pins you set yourself. Miss a turn and you notice the way you would on paper, by looking. Off route warning is planned and not built. If you want instructions, a Garmin or a phone app is the right tool, and the comparison page says so plainly.

Which readers does it run on, and where do I get one?

The Xteink X4 today, with the X3 sharing the same binary. The X4 Pro is a different chip and needs its own build. Buying an X3 or X4 Developer Edition through the CrossPoint project's shop sends a cut back to the upstream contributors whose work this is forked from, which is the path we suggest. Details on the hardware page.

How do I install it?

Today: a USB cable, PlatformIO for the firmware and a sideloaded APK for the phone. That is a maker's install and we say so. A one click installer in the browser and a signed app are the next milestone, after pre built map coverage, because a stranger who flashes successfully and then sees a blank map is a worse outcome than one who never flashed. What runs today is listed, dated, on the development page, and the phone side is on the app page.