Locator Pro v3.0
Advanced anchor with long-range tracking capabilities for industrial RTLS networks.
Locator Pro v3.0 is a feature-rich anchor and gateway device for industrial RTLS networks. It is enabled with PA-LNA circuitry for both UWB and BLE parts to reach 300–500+ meters range to the RTLS tags. P2P ranging between two Locator Pro devices allows reaching 1000–1500 meters when the local regulations don’t prohibit higher transmission levels.
It includes all typical interfaces and connectors, which are needed for enterprise-grade installations at your locations — for example: 802.3at-af PoE, WLAN and USB interfaces.
Interfaces
| Interface | Notes |
|---|---|
| UWB TWR | ranging, anchor role |
| UWB TDoA | ranging, anchor role |
| Unified TDMA | frame types 0x24 / 0x25 |
| BLE GATT | product-specific base UUID — see below |
| GATT Data Sync | 0x5130 / 0x5131 equivalents |
| Sensor TLV | record definitions present on the product |
| Hall Sensor | magnetic switch fitted on the board |
| BLE Ext Advertising | carrier envelope and 255-byte scan buffer |
| MQTT | direct uplink; /Sensors, /Alarm, /GNSS, /Diag |
No CAN or RS-485 controller is fitted; the unit is not chained. Being mains or PoE powered, it reports no battery record.
Hardware
| Subsystem | Part |
|---|---|
| Main MCU | low-power STM32H7 |
| UWB subsystem | Qorvo/Decawave DW1000 with PA-LNA modules and external SMA antennas |
| BLE subsystem | Nordic nRF52840 with nRF21540 FEM module for BLE range extension |
| Wi-Fi | Texas Instruments CC3100 — 2.4 GHz only, SMD chip antenna and UFL connector for an external antenna |
| PoE | ON Semiconductor 802.3at-af module with a custom PoE circuit |
| Ethernet | Microchip Ethernet RMII PHY module |
| Barometer | Bosch BMP390 |
| USB | Amphenol USB 3.2 module |
| Enclosure | IP67-IP68 for harsh industrial environments |
Connectors
| Connector | |
|---|---|
| USB Type-C | protected, brought out to the housing |
| Ethernet RJ45 | protected, brought out to the housing |
| UART for modems | internal — NB-IoT by default, see expansion connector |
| microSD card slot | internal |
PA / LNA front ends
Locator Pro carries two independent front ends — one on the UWB radio, one on the BLE radio. They are separate parts, separately controlled, and either can be fitted and working while the other is not.
Indicative gain and reach
Figures below are approximate, from the front-end parts' typical characteristics. Actual reach depends on antenna, mounting, terrain and local regulatory limits, and should be confirmed by survey on each site:
| UWB | BLE | |
|---|---|---|
| Transmit gain | ≈ +13 dB | ≈ +12 dB (+8 → +20 dBm) |
| Receive gain | ≈ +14 dB | ≈ +13 dB |
| Link budget | ≈ +25 dB | ≈ +25 dB |
| Typical reach without | ≈ 60–100 m | ≈ 50–100 m |
| Typical reach with | ≈ 300–500 m | ≈ 300–500 m |
Range does not scale with power the way the decibels suggest. In free space every 6 dB doubles the distance, so +25 dB is a theoretical 15× — but real propagation loses more per metre than free space does, and the practical result is closer to 3–5×. Indoors, through structure, expect less again: the front end buys penetration rather than open-field distance.
UWB transmit power is capped by regulation, not by the amplifier. Most jurisdictions limit UWB to −41.3 dBm/MHz EIRP, and EIRP counts antenna gain. On the UWB side the amplifier's practical job is to reach that ceiling after cable and connector losses rather than to exceed it; the reach gain comes substantially from the receive side.
Locator Pro to Locator Pro UWB ranging
The figures above are for the normal case — a Locator Pro ranging to a tag. Only one end of that link is amplified: the tag transmits and receives on its own radio, so each direction benefits from the front end once.
Ranging between two Locator Pro units amplifies both ends. Each direction now gets the transmitting unit's amplifier and the receiving unit's low-noise amplifier, so the gains add rather than apply singly:
| Link | Amplified | Approximate gain per direction | Estimated line-of-sight reach |
|---|---|---|---|
| Locator Pro ↔ tag | one end | ≈ +13 dB | ≈ 300–500 m |
| Locator Pro ↔ Locator Pro | both ends | ≈ +27 dB | ≈ 1–2 km |
These are estimates for clear line of sight with both units mounted high enough to keep the Fresnel zone unobstructed — masts, building corners, pit rims. At kilometre distances the mounting matters more than the amplifier: a link that grazes terrain or vegetation will fall well short of the figure regardless of front-end gain.
The application is spanning distances that would otherwise need infrastructure in between — linking a pit to a plant, opposite sides of a yard or quarry, or across water, where running a cable or placing intermediate anchors is impractical.
This mode is available on request rather than as a standard configuration. Both units are anchors by default, so neither initiates ranging to the other; the pairing requires a specific configuration rather than a parameter change on a stock unit. Contact Leantegra with the site geometry and the intended span.
UWB front end
The amplifier and low-noise amplifier are driven by the DW1000's own GPIO lines, so the switch between transmit and receive happens inside the radio's sequencing:
| DW1000 line | Drives |
|---|---|
| GPIO4 / EXTPA | LNA shutdown — high during transmit, so the LNA is off while the PA is driving |
| GPIO5 / EXTTXE | RF switch control — selects the transmit or receive path through both switches |
| GPIO6 / EXTRXE | not connected on this board |
Path selection comes entirely from GPIO5; a single line drives both RF switches through an inverter, so transmit and receive paths cannot both be selected. Enabling the front end requires the GPIO de-bounce clock, and fine-grain transmit sequencing must be disabled — that is mandatory whenever an external amplifier is in use, not a tuning choice.
GPIO6 must be left inactive on this board. Driving it adds internal switching load with no external effect, because it is not wired to the front end — bench measurement put SPI corruption at roughly 3% with it inactive against 17% with it driven.
After programming, the firmware reads the configuration registers back and latches a status flag, which drives a front-end indicator LED. The front end is therefore verified rather than assumed: if the sequence did not take, the indicator does not light.
The amplifier's supply is not gated by firmware — it is powered whenever the UWB radio is. During receive it is the RF switch routing, not a power rail, that takes the transmit path out of circuit.
BLE front end — nRF21540
The BLE front end is an nRF21540 module. Its transmit and receive enable lines are handed to the SoftDevice, which toggles them from the radio ramp-up itself, so no application code sits in the timing path:
| Signal | Control |
|---|---|
| TX_EN | SoftDevice, from radio ramp-up — active high |
| RX_EN | SoftDevice, from radio ramp-up — active high |
| PDN | static GPIO — active low; held high for the application's lifetime |
| MODE | static GPIO — selects the output-power setting |
| ANT_SEL | tied to ground on the PCB — one antenna port, no switching |
The module's SPI interface is not wired on this board, so everything configurable is set by those two static GPIOs. The part's registers cannot be read back — unlike the UWB side, firmware asserts the pins but cannot verify the module's state.
The default is the lower of the two power settings. Raising it to the higher setting is a deliberate change, not a default: it needs a supply-current budget check, and the transmitted power is a regulatory question at the antenna because EIRP includes antenna gain.
Enabling the front end reserves one GPIOTE channel and two PPI channels for as long as it is active. Antenna diversity is not offered — the second antenna port is terminated on the board, so one port is permanently selected.
GATT — a product-specific base UUID
Locator Pro does not share the fleet vendor base UUID. Its base and characteristic offsets differ, so its 16-bit values are not the same characteristics as the fleet's 0x51xx. A client must discover this product's service rather than assume the fleet layout.
Alignment across the line is instead by runtime parameter ID and MQTT payload key, so a setting carries the same meaning on every product even where the GATT handle differs. See BLE GATT for the shared parameter-ID space.
Connectivity
Ethernet with PoE, WiFi, and an optional NB-IoT module. The unit publishes directly to the broker rather than through a chain master.
Power over Ethernet
PoE carries data and power on the same cable, so a unit needs no local mains supply. That is what makes the mounting positions this product targets practical — mast heads, pit rims, yard lighting columns, building corners — where the position that gives clear line of sight is rarely the position that has a socket.
Both PoE standards are supported, and the unit negotiates with the switch rather than requiring a particular one:
| Standard | Also called | Power at the source | Power at the device |
|---|---|---|---|
| IEEE 802.3af | PoE, Type 1 | up to 15.4 W | up to 12.95 W |
| IEEE 802.3at | PoE+, Type 2 | up to 30 W | up to 25.5 W |
The difference between the two figures in each row is cable loss, which the standard budgets for over 100 m. Supporting 802.3af means the unit runs from older or lower-budget switching already installed on a site; 802.3at gives headroom where it is available.
Switch compatibility
Interoperability has been verified against Cisco PoE switches. Any switch conforming to either standard is expected to work, but Cisco is the installed base most often encountered on industrial sites, and it is the equipment the unit has been tested against.
Check the switch's total power budget, not just its per-port rating. A switch advertising 802.3at on every port rarely has the supply to deliver it on every port at once. Sizing a deployment on the per-port figure is the common way to arrive at anchors that negotiate, run, and then drop when the rest of the site is powered up.
Passive or non-standard PoE injectors that put voltage on the cable without negotiating are outside both standards; use a conforming injector or switch.
Barometric reference
The anchor carries a barometer. In differential barometry the fixed anchor is the reference end: tags report pressure, and the anchor reading converts those into a floor or elevation estimate. Baro record definitions are Sensor TLV types 0x03 (raw) and 0x04 (aggregate).
Expansion connector
The board carries a connector for an external connectivity module. The module is a separate board that plugs onto the main board inside the enclosure, rather than an interface brought out to the housing.
NB-IoT is the module fitted by default. It gives the anchor a cellular uplink where neither Ethernet nor WiFi reaches — remote masts, pit rims, and yard positions chosen for line of sight rather than for proximity to network infrastructure.