Inside the Northing receiver: what the hardware actually does

Spec sheets in this market are written to impress other spec sheets. This is what the hardware actually does, why each piece is there, and what it deliberately does not have.

Multi-band, multi-constellation tracking

The receiver tracks all four global satellite constellations — the American, European, Chinese, and Russian systems — on multiple frequency bands, including the high-accuracy band that most consumer hardware ignores.

Multi-band is not a spec-sheet flourish; it is what makes centimeter work possible at all. The ionosphere delays radio signals by an amount that depends on their frequency, so a receiver listening on two or more frequencies can measure that delay directly instead of guessing it from a model. Single-band consumer chips — the kind in a phone — cannot, which is a large part of why a phone is stuck at metres. There is more on that in RTK vs PPP.

Tracking four constellations rather than one is about how much sky you have. Under a hedge, in a yard, or in a deep cutting, what limits you is the number of satellites still visible; drawing from four systems instead of one is the difference between working and waiting in exactly the places where work is hardest.

That extra band is also what powers Northing Global, the free positioning mode built into every receiver.

Your phone is the monitor — by design

There is no screen, no proprietary terminal, and no cellular modem. The receiver speaks Bluetooth Low Energy to the phone already in your pocket: position and status stream out, corrections stream in at about 1 kbps.

Each of those absences is a decision:

• No screen means nothing to crack, nothing to wash out in sunlight, and no second-rate map application you are stuck with. You already own a better display than any vendor would fit.
• No cellular modem means no second SIM, no second data plan, no roaming surprises, less power on the roof, and one less radio to certify in every market we sell into.
• No proprietary connector on the data path means the protocol is the interface, and the protocol is published.

One device on the roof; zero new subscriptions for connectivity.

An open protocol, not a walled garden

The Bluetooth protocol is published and a free Swift SDK is on the way. Any app can read position, fix state, satellite counts, and health data without asking our permission, and without a partnership agreement.

This is the part that is easiest to say and hardest to reverse, which is why it is built the way it is. A published protocol cannot be quietly withdrawn from the people already using it. Tractor GPS is the first app on the receiver; it will not be the only one. If you are a developer, this is a platform rather than a peripheral.

Field updates that cannot brick it

A receiver bolted to a roof bracket in February is not something anyone should have to post back. So the update path is built defensively, in layers:

1. Signed firmware. Updates are cryptographically signed; the receiver refuses anything that does not verify.
2. A/B partitions. The new version lands beside the running one. If it fails to boot or misbehaves, the receiver rolls back to the previous version by itself.
3. Resumable transfers. An update interrupted by a dropped Bluetooth link resumes where it left off rather than starting over.
4. Crash-loop safe mode. Repeated failures drop the unit into a minimal mode that can still be talked to and re-flashed.
5. A browser-based recovery flasher. For the genuine worst case, a web page and a USB cable — no special hardware, no dealer visit, no return shipping.

Each layer exists because the one above it can fail. That is the whole design philosophy in one list.

Status you can trust

Precision you cannot verify is decoration. The receiver continuously reports fix type, satellite counts, correction age, and signal health to any connected app.

More importantly, it runs an independent watchdog on the corrections themselves. GNSS engines have a well-known failure mode: when a correction stream dies silently, they keep reporting centimeter confidence while true error drifts. We measured it — quality flags, accuracy estimates and correction-age fields all frozen while real error grew from 7 cm toward 40 cm. The watchdog does not ask the engine’s opinion. If corrections stop flowing for 30 seconds it raises “Stale Corrections” to every connected app regardless.

The same instinct shows up elsewhere in the firmware: every optional feature can be turned off individually if it ever misbehaves in the field, rather than the whole unit being all-or-nothing. Details of the correction path are in how Northing RTK works.

Mounted where position actually matters

The receiver is a single sealed unit that goes where you need position truth — roof, bar, pole, or bracket — powered from 5 V USB. There is no separate antenna to site, no cable run to get wrong, and no control box in the cab. Everything that would normally be three boxes and two cables is one box and a phone.

That integration is a positioning decision as much as a packaging one. In a split system the antenna is the thing whose position you are actually measuring, and every metre of coax between it and the receiver is an opportunity for loss, water ingress, and a connector working loose in vibration. Putting the antenna and the receiver in one sealed enclosure removes the whole category, and it means the point you mount is the point you measure — no offsets to remember, no “which end of the bar was it again” six months later.

USB power rather than a proprietary harness is the same instinct: the cable is one you can already buy anywhere, from a supply you probably already have on the machine.

There is deliberately no battery inside. A battery is a consumable that ages badly in a hot cab and a cold shed, and it turns shipping and certification into a separate compliance project. The receiver runs from the machine it is on.

Diagnostics that make support a two-message conversation

When something is wrong in the field, the usual failure is not the fault — it is the six emails spent establishing what the fault was. So the receiver keeps the evidence and the app can package it: fix history, correction age, satellite counts and signal levels, firmware version, and what the watchdog saw, exported as a support bundle you can send in one message.

The point is that support starts from data rather than from a description. “It went float near the trees at about four o’clock” is a hard thing to diagnose; the same event with the satellite counts attached usually is not. It also keeps us honest — a diagnostics path that only we can read would be a way to avoid publishing awkward numbers, and this one produces the same records that the measured claims on this site come from.

What the first pairing looks like

There is no commissioning procedure. Mount it, power it from 5 V USB, pair it once in the app over Bluetooth, and it starts working: no correction server address to type, no mount point, no port, no username and password, no calibration drive, no dealer visit. The receiver has no keypad and needs no network credentials of its own, because the phone is the connection.

What it does not do yet

A capability list is only worth reading if the same page will admit to the gaps, so here are the ones we get asked about. These are described as roadmap items rather than dated promises, deliberately — a shipped date we have not earned is exactly the kind of claim this site exists not to make.

• Raw observation logging for post-processing. On the roadmap. If your workflow is PPK — log now, correct later — this is not the receiver for you today.
• A published SDK. The Bluetooth protocol is public now; the free Swift package that wraps it is on the way, with other languages following the demand rather than a plan.
• An AgOpenGPS-native mode. On the roadmap, and wanted — that community buys receivers constantly and is unusually good at finding the edges of one.

Everything else on this page is implemented and field-tested, and where a number appears it carries the conditions it was measured under.

Works on day one, works after you cancel

With the included Northing RTK subscription: ±2.5 cm, fixed in seconds, re-fixed in 1–2 s after obstructions (measured on logged drive sessions, open sky for the accuracy figure).

Without any subscription, ever: standalone GNSS plus Northing Global — 10–20 cm class accuracy once converged, anywhere on Earth, no account and no data plan. Reduced, convergence-based, and explained honestly in RTK vs PPP.

The hardware never bricks, never phones home for permission to work, and never holds your fields hostage. That is not generosity; it is the only architecture that is honest about what you bought.

See the two services side by side, or what it costs.