Dusun DSGW-200 angle-of-arrival locators

The DSGW-200 is a ceiling-mounted Bluetooth locator with an array of sixteen antennas. Instead of measuring how loud a tag is, it measures the direction the tag's signal arrives from. Omaya turns those directions into a point on the floor plan, to within a metre or so: close enough to tell two desks apart, not just two rooms.

• One locator places every tag it can see: Omaya follows the direction down to the tag's height.
• Two or more on a floor also run Dusun's own positioning engine, which combines all their angles. Where it has an answer, Omaya uses that one.
• Next to ordinary gateways: a tag a locator can see is placed by the locator; everywhere else, the ordinary Bluetooth gateways place it as before.

What you do in Omaya

1. Create the connector and copy its prefix — A
2. Register each locator by its Bluetooth id — B
3. Place it, and set its height and facing — C
4. Download AOA.csv for the master locator — D
5. Register the tags and check — E

Before you start

• Tags that support direction finding. The locator measures a short tone (a Constant Tone Extension) that the tag adds to its advertisement, in Silicon Labs' format. Dusun's AoA tags send it. Ordinary beacons, cards and wristbands do not: the locator cannot give a direction for them.
• A ceiling, 3 m or higher if you can. One locator covers a circle about twice its height across in each direction; areas two locators overlap are the most accurate. Mount it flat, antennas facing the floor.
• The floor plan's size in metres, and every locator on the same network (for two or more: the master finds the others on the local network).
• Wired network or Wi-Fi. Over a mobile connection the angles arrive too late to be combined.

Step 1 — Network and sign-in

1. Power it over PoE (or its USB-C adapter) and connect Ethernet.
2. Browse to the address your DHCP server gave it. Without a network yet, join its own Wi-Fi, DS-AOA_ followed by the last four characters of its MAC (factory password 12345678), and browse to 192.168.66.1.
3. Sign in as root (factory password root) and set a new password under Advance → Administration.

Write down two things from its pages: the MAC address on Home (30:AE:7B:…, its network card) and the Locator ID under IOT Services → AOA Direction Finding (ble-pd-…, its Bluetooth radio). Omaya needs both.

Step 2 — Send its data to Omaya

The locator publishes on its own MQTT topics, silabs/aoa/angle/… and silabs/aoa/position/…, which carry the locator's and the tag's ids. Omaya receives them under the connector's prefix, so the topics are passed on with a broker bridge: on the master locator if it runs Mosquitto, or on any small machine on the site network that the locators publish to.

# Mosquitto, e.g. /etc/mosquitto/conf.d/omaya.conf
connection omaya
address omaya4.synchroweb.com:1883
topic silabs/aoa/# out 0 "" omaya/<organisation>/<token>/dusun_aoa/

The prefix is on the connector (step A). In IOT Services → AOA Direction Finding, point the locator's MQTT server at the bridging broker, and keep reportMode at ANGLE.

In Omaya

A. Create the connector

Connectors → IoT Gateway (MQTT) → add, with Vendor: Dusun AoA locator (DSGW-200). Save. The connector shows the prefix to bridge under, omaya/<organisation>/<token>/dusun_aoa/. One connector serves every locator in the organisation.

B. Register the locators

Device → Gateway → add one per locator:

Field	Enter
Name	where it hangs, e.g. L3 open office — north
MAC address	the Locator ID without its prefix: ble-pd-588E814405DC is 58:8E:81:44:05:DC
Device Model	Dusun AoA locator (DSGW-200)
Location, venue	where it is

C. Place, height and facing

On the venue's floor plan, click the locator in the Gateways list and click where it hangs. In the bar above the plan:

Field	Enter
Height	the height of the locator above the floor, in metres
Facing	which way the 0° mark on the locator points, seen on the plan: degrees counter-clockwise from the plan's right. 0 = right, 90 = up, 180 = left, 270 = down
LAN MAC	the network MAC from its Home page (30:AE:7B:…)

Save. Without a height and a facing, the locator's angles cannot place a tag; the floor plan says so on the locator.

D. The setup file

With two or more locators on a floor: Download AOA.csv at the foot of the floor plan's Gateways list. It holds each locator's position, height and facing, measured from the plan, so the locators' own engine works on the same map as Omaya. On the master locator, IOT Services → AOA Management → AOA Network Setup, upload it. The master finds the others on the network in about 45 seconds and lists them.

Download and upload it again whenever a locator is moved, turned or added.

E. Tags and check

Register each tag under Device → Sensor with its MAC, like any other.

• Device → Gateway: a locator shows online while it sees a tag.
• The Live Monitor: the tag appears on the plan; its trail's method reads Angle of arrival (or Angle of arrival (locator engine) where two or more locators combine).
• A quick walk: stand under a locator, then two metres from it in the direction of its 0° mark. The marker should follow you to the right; if it goes the other way, check Facing.

Good to know

A locator is online while it sees a tag. It does not report on its own when nothing is in range, so an empty floor at night shows its locators as offline.

A tag's height matters. The angle is followed down to the tag's height: the tag model's height if it has one, otherwise the floor's, otherwise 1 m.

Ordinary gateways and locators together. Where a locator can see a tag it decides the floor and the point; elsewhere the ordinary gateways do. The two need no setting to share a floor.

When it disappoints

No tags at all. The bridge prefix against the connector, character by character; the Locator ID registered as the gateway's MAC; then whether the tags are AoA tags (step Before you start).

Tags in the right area but mirrored or turned. Facing (step C). A locator mounted facing up, or on a wall, needs Dusun's orientation values and is not covered by this guide.

Two or more locators, but the method stays Angle of arrival. The master has not got the setup file, or it is out of date: download AOA.csv and upload it again (step D).