Run Your Own MQTT Broker for 60GHz Radar: An Apache Artemis Setup Guide

The radar setup guide opens with a hard prerequisite: the broker has to be ready before the radar is configured. It tells you which four values to type into the module — server address, ClientID, username, password — and lists your options (self-hosted EMQX or Mosquitto, a managed cloud broker, or a public test broker for a first try). What it does not do is stand one up.

This article is that missing step. It builds an MQTT broker you control, using Apache Artemis — the broker we use ourselves while debugging radar prototypes. If Home Assistant already talks to some broker, you can skip to the sections you need.

Written against Apache Artemis 2.50.0. The CLI and broker.xml layout are stable across the 2.x line, but always diff your own copy before editing.

What you need

• A machine on your LAN that stays on (mini-PC, NAS, or server) with a Java 17 runtime
• About 1 GB of free RAM
• A broker account plan: one account per client, which we create below

Our radars talk over plain TCP, so everything here uses port 1883.

Install Artemis

Grab the current release from the official download page https://artemis.apache.org/components/artemis/download/, then create an instance:

tar zxvf apache-artemis-2.50.0-bin.tar.gz
cd apache-artemis-2.50.0/bin
./artemis create /opt/radar-broker

The create step asks for a console username and password, and whether to allow anonymous login. Answer N to anonymous — every client gets its own credentials.

Start it in the foreground to check it comes up:

/opt/radar-broker/bin/artemis run

For a machine that reboots, install it as a service instead:

/opt/radar-broker/bin/artemis-service install
/opt/radar-broker/bin/artemis-service start

Log into the console at http://<host>:8161/console.

That port, 8161, is the management console. It is not the MQTT port. Typing it into the radar's configuration page is the most common reason a module "connects" but nothing arrives.

Enable MQTT (the step that is not the default)

Artemis is a multi-protocol broker. Its default acceptor serves its own core protocol on 61616; MQTT is something you ask for explicitly.

Stop the broker, edit /opt/radar-broker/etc/broker.xml, and add one acceptor inside <acceptors>:

<acceptor name="mqtt">tcp://0.0.0.0:1883?protocols=MQTT</acceptor>

Restart and confirm it listens:

ss -ltnp | grep 1883

Keep three ports straight:

Variations use the same pattern: MQTT over WebSocket (protocols=MQTT,WS on another port) or TLS on 8883. Both are documented for your version; start with plain 1883 on a trusted LAN.

Create one account per client

With the default properties-based security, add users in etc/artemis-users.properties and map them to roles in etc/artemis-roles.properties. Create three:

• radar — for finished 60 GHz modules
• radar-gw — for the ESP32 gateway
• ha — for Home Assistant

Then restart. Because anonymous access is off, any client that connects without credentials is rejected — the second most common cause of "the radar shows no data".

If you want isolation between them, add a <security-setting> block in broker.xml restricting each role to its own topic prefix.

Point the finished modules at it

You now have exactly the four values the setup guide asks for:

Now go back to the setup guide: hold the button for 10 s, join the RadarConfig hotspot, open 192.168.0.1, enter them, then use BK_BLE5.apk to send your 2.4 GHz Wi-Fi credentials.

Verify by subscribing to the model's report topic with any MQTT client — /Radar60SP/{DeviceID}/# (sleep), /Radar60FL/ (fall), /RadarHP/ (presence) — exactly as in Step 5 of the setup guide.

Point the ESP32 gateway at it

The R60ABD1 has no network of its own; the ESP32-S3 gateway reads its UART frames and publishes them. On the firmware side the broker is three lines of configuration:

const char* mqtt_server   = "<Artemis host IP>";
const int   mqtt_port     = 1883;
const char* mqtt_username = "radar-gw";
const char* mqtt_password = "<password>";
// connect with a unique client id, then:
client.publish("radar/R60ABD1/state", payload.c_str());

Artemis speaks MQTT 3.1.1, which is what PubSubClient uses. Give each gateway a unique ClientID.

Point Home Assistant at it

Add the MQTT integration with the same host, port 1883, and the ha account. Then declare entities as shown in the R60ABD1 Home Assistant guide for UART-only sensors, or in the per-model guides for finished modules.

Verify end to end

1. Console → connections: one line per radar, one for the gateway, one for Home Assistant.
2. Subscribe to a report topic and watch raw JSON arrive.
3. In Home Assistant, check Developer → States for your entities.

Troubleshooting

Where to go next

• The 2.4 GHz / MQTT device setup: radar setup guide
• The UART-only path: R60ABD1 + ESP32-S3 gateway
• Consuming it: R60ABD1 in Home Assistant
• Which module does what: 60 GHz / 24 GHz module spec sheet

Both the finished 60 GHz radars and the bare modules are on Tindie.