LoRaWAN Duress Button System

1. System Overview & How It Works

Project: 7x wireless duress buttons feeding into an existing Bosch Solution 6000 alarm panel.

Use case: Mining camp, one button per laundry, roughly 100–500m range across the park.

Target panel: Bosch Solution 6000 (existing, with CM705B expander, 4G failover, network backhaul).

Back end: Milesight UC501 LoRaWAN IoT Controllers → Milesight UG67 outdoor gateway → Raspberry Pi (Node-RED + MQTT) → 8-channel relay board → Bosch CM705B zones.

1.1 Architecture at a glance

1.2 How it works, step by step

1. Staff member presses the 40mm red e-stop button inside a laundry
2. Button pulls UC501 GPIO_1 low (dry contact closed)
3. UC501 detects the DI change and sends a LoRaWAN uplink (Class A, confirmed, up to 3 retries)
4. UG67 at head office receives the uplink over AU915
5. UG67 publishes an MQTT message to the local Mosquitto broker on the Pi
6. Node-RED flow decodes the payload, matches the device EUI to a button/zone mapping, and pulses the matching GPIO high for 3 seconds
7. Opto relay closes the dry contact — Bosch zone sees alarm
8. Bosch Solution 6000 raises a 24-hour Duress alarm, reported to monitoring via IP + 4G failover
9. Node-RED also publishes a push notification (optional) so head office staff see which laundry triggered

1.3 Supervision — how you know nothing is broken

• UC501 heartbeat: every 6 hours sends battery, GPIO state, RSSI
• Node-RED watchdog: if any UC501 misses two consecutive heartbeats (12+ hours silent), the Pi pulses the "Trouble" relay → Bosch sees a trouble zone → monitoring alerted
• UG67 gateway watchdog: Pi pings gateway every 60s. If unreachable for 5 min, Trouble relay fires
• Pi watchdog: systemd watchdog restarts Mosquitto/Node-RED if they crash. Bosch sees the Trouble relay in safe state if Pi is totally down
• Confirmed uplinks: UC501 set to Class A with ACK. If the first attempt fails, it retries up to 3 times within ~15 seconds. This is the fix for the false-positives and drops of the old P2P setup.

2. Bill of Materials

Three groups of parts: per-laundry kit (you need 7 of these), head office kit (1 of these), and test bench gear (should already have most of it).

2.1 Per-laundry kit (×7)

Per-laundry subtotal: ~$329 ex-GST × 7 = ~$2,303

2.2 Head office kit (×1)

Head office subtotal: ~$1,290 ex-GST

2.3 Test bench gear

3. Pre-Build: Supplier Setup

Do these four things before you order anything.

4. Phase 1 — Head Office Hub (The Brain)

4.1 Flash the Raspberry Pi

4.2 Install Mosquitto (MQTT broker)

Lock it down with a username and password:

Test that auth works:

4.3 Install Node-RED

Verify it's running by browsing to http://lora-bridge.local:1880 in your browser.

Install the required palette nodes via Manage Palette → Install:

• node-red-contrib-rpi-gpio
• node-red-node-pi-gpio (usually pre-installed)
• node-red-contrib-buffer-parser (for decoding hex payloads)
• node-red-dashboard (optional, for a local status UI)

4.4 Wire up the 8-channel relay board

Typical 5V/12V opto-isolated 8-channel relay board pinout:

• VCC → Pi 5V (pin 2)
• GND → Pi GND (pin 6)
• JD-VCC → 12V+ (external PSU). Remove the VCC↔JD-VCC jumper for proper isolation.
• GND2 → 12V−
• IN1..IN8 → Pi GPIOs (see mapping table below)

Each relay has NC / COM / NO terminals. Wire COM + NO to the Bosch zone so that when the relay energises, the zone shorts through whatever EOL config Bosch expects.

4.5 Bosch zone wiring (reuse existing CM705B zones)

The existing CM705B in the head office already has 7 zones connected to the broken P2P relay rig. Disconnect those and re-terminate to the new 8-channel board.

Typical Bosch Solution 6000 single-EOL wiring

• Relay open (normal): resistor in circuit, zone reads "sealed"
• Relay closed (alarm): resistor shorted, zone reads "alarm"

Zone programming (only if it must change)

• Zone Type: 24-Hour Silent Duress or 24-Hour Audible Duress (client preference)
• Area: none (always armed)
• Pulse Count: 1
• Resistor: match physical wiring
• Zone Name: "LAUNDRY 1 DURESS", "LAUNDRY 2 DURESS", etc.
• Zone 8 (trouble): 24-Hour Tamper or Monitor Point named "DURESS SYSTEM TROUBLE"

4.6 Head office enclosure layout

Mount on the wall next to the Bosch panel. Power the Pi and relay board from the 12V rail so they share a common ground with the Bosch zones.

5. Phase 2 — Gateway (UG67)

5.1 Initial gateway bring-up

5.2 ChirpStack built-in network server setup

UG67 ships with ChirpStack baked in. In the ChirpStack UI:

1. Network Server → General: Enable.
2. Applications → Add: name duress-system, payload codec Custom Javascript codec functions (we'll paste a decoder in Phase 4).
3. Profiles → Device Profile → Add:
   • Name: UC501-Duress
   • LoRaWAN MAC Version: 1.0.3
   • Regional Parameters: RP002-1.0.3
   • Class: Class A
   • Max EIRP: 16 dBm
   • ADR: Enabled
4. Integration → MQTT:
   • Broker: tcp://lora-bridge.local:1883 (the Pi)
   • Username: lora / password as set earlier
   • Topic prefix: application/duress/

5.3 Mounting and antenna

1. Mount UG67 as high as practical — roof, mast, parapet. Line of sight to the laundries is the goal.
2. Mount the external high-gain omni antenna on a short pole above the UG67 body, connected via the LMR-240 jumper.
3. Use an N-type coaxial surge arrestor inline if the antenna is on a mast (grounded to mast ground).
4. Run Cat6 PoE back to the head office switch and the Pi enclosure.

6. Phase 3 — Field Nodes (UC501 + Button)

6.1 UC501 base configuration (via NFC)

6.2 Field enclosure assembly (per unit)

Prep the enclosure (Jaycar HB6131 or similar)

• Drill a 22mm hole dead centre of the lid for the e-stop button
• Drill one M20 gland hole on the bottom for the antenna cable
• Drill one 12mm hole for the tamper lever switch (internal, against lid)
• Apply a thin bead of silicone around the button bezel after mounting

Mount the components inside

• UC501 screwed to the rear wall of the enclosure (use the mounting ears)
• Tamper microswitch hot-glued or screwed so the lever touches the lid when closed. When the lid opens, the lever releases and the NC contact opens.
• E-stop button threaded through the lid, bezel nut tight, silicone seal

Wiring

• Use 24AWG stranded wire, ferruled ends into UC501's screw terminals
• Keep wiring neat, zip-tie to internal standoffs

Antenna

• External antenna mounts through the top of the enclosure via the M20 gland
• Use an N-type bulkhead adapter with O-ring for water sealing
• Antenna body outside the enclosure, cable inside to the UC501 SMA port

Final seal

• Close the lid, capture screws (or key lock), apply silicone around any gaps
• Optional: drop a desiccant sachet in the base to manage humidity in the laundry environment
• Apply the "EMERGENCY DURESS — PRESS TO ACTIVATE" vinyl decal to the lid

6.3 Wall mounting position (install guide for the site installer)

• Wall mount the enclosure 1200–1400mm above finished floor level — wheelchair + standard reach
• Not behind doors, machines, or inside cupboards
• Within 2m of the main laundry entry/exit path
• Visible and clearly labelled
• Antenna as high as possible, never pointing directly into a metal washing machine

7. Phase 4 — ChirpStack Device Registration

7.1 Add each UC501 as a device

For each UC501, in the UG67 ChirpStack UI:

1. Applications → duress-system → Devices → Create:
   • Name: laundry-01 through laundry-07
   • Device EUI: the EUI you wrote on the sticker
   • Device Profile: UC501-Duress
   • Save
2. On the device page → Keys (OTAA): paste the App Key you set in ToolBox (must match exactly). Save.
3. Power cycle the UC501. It should JOIN within 30 seconds.
4. Watch the Device Data tab — you should see a join accept, then uplinks as you press the button.

7.2 Payload codec

UC501 uplinks are TLV-encoded binary. Paste this codec into the device profile or application:

7.3 Verify the MQTT stream

SSH into the Pi and subscribe:

Press the e-stop button — you should see an MQTT message within 2 seconds:

8. Phase 5 — Node-RED Flow

8.1 Device mapping

Create /home/cameron/duress-mapping.json on the Pi:

Replace the EUIs with your actual UC501 EUIs from the stickers.

8.2 Node-RED flows (high level)

Flow 1 — Duress trigger

Flow 2 — Watchdog (heartbeat supervision)

Flow 3 — Heartbeat recorder

Flow 4 — Gateway liveness watchdog

8.3 Reference flow JSON

A complete pre-built flow JSON will live alongside this guide as duress-flow.json. Import into Node-RED via Menu → Import → paste JSON → Deploy.

8.4 Active-low relay configuration

In each rpi-gpio out node in Node-RED:

• Pin: the BCM number from the mapping table
• Type: Digital Output
• Initialise pin state: Yes → Initial level High (off for active-low)
• Tick Active Low if your relay board is active-low (most cheap ones are)

9. Testing Protocol

Run through this checklist on your bench before anything goes to site.

9.1 Component tests

• Pi boots, SSH accessible, time sync OK
• Mosquitto running, auth enforced, mosquitto_pub / sub work
• Node-RED reachable on :1880, flows deployed, no errors
• UG67 accessible on LAN IP, firmware up to date
• ChirpStack network server running, gateway state "Online" with recent uplinks
• All 7 UC501s joined to the application and sending heartbeats
• Relay board wired, all 8 relays fire individually from Node-RED test inject

9.2 End-to-end tests (per button)

• Press button 1 → MQTT observed → Node-RED logs "Laundry 1 duress" → Relay 1 clicks → Bosch test zone 1 shows alarm → panel dials monitoring (or observe in engineer mode)
• Repeat for buttons 2–7
• Release button → relay auto-releases after 3 seconds → Bosch zone returns to sealed
• Open enclosure lid → tamper triggers → separate zone activates (if allocated) or log entry
• Pull UC501 battery → wait 13 hours → watchdog fires Trouble zone → Bosch trouble alarm
• Reconnect UC501 → next heartbeat clears the watchdog → Trouble relay releases
• Unplug UG67 Ethernet → 5 min later Trouble relay fires
• Reboot Pi → Mosquitto + Node-RED auto-start → system recovers

9.3 Range testing

• Put a UC501 at expected max range (500m, line-of-sight-ish) → press button → confirm uplink arrives within 2 seconds
• Check RSSI / SNR in ChirpStack — aim for RSSI > −120 dBm, SNR > −5 dB for reliable operation
• Test inside a metal-clad laundry shell if possible — worst-case environment

9.4 Stress tests

• Press 3 buttons within 1 second → all 3 should register (LoRaWAN may queue)
• Hold a button down for 30 seconds → fires alarm on press, no extra events, releases cleanly
• Rapid-fire the same button 10 times in 10 seconds → all 10 hit the Bosch log

9.5 Before handover

• Document all device EUIs, App Keys, and zone mappings in a handoff doc
• Back up UG67 config, Pi SD image (dd), Node-RED flows (flows.json), Mosquitto config
• Print the "quick reference card" — what each zone means, who to call, how to silence

10. Deployment Notes

• Do a site survey first. Walk the park with a UC501 and a portable gateway (or use a Milesight test device in scanner mode). Log RSSI at every intended button location BEFORE committing mounting points.
• Gateway placement wins or loses this job. Spend real time finding the highest point with the best line of sight. Don't shortcut.
• Keep a spare UC501 and a spare e-stop button onsite. Mining camps are hard on gear.
• Plan the Bosch zone programming change carefully. Do it out of business hours, and have the client confirm monitoring knows you're testing so every duress alarm doesn't dispatch response.
• Label everything. Enclosures, cables, zones, relay channels. Future-Cameron will thank you.

11. Open Questions & Risks

12. Appendix — Files & References

Files in this project folder

Located at /mnt/shared/research/lorawan-duress/:

• LoRaWAN-Duress-Build-Guide.md — the source markdown for this guide
• duress-flow.json — Node-RED flow export (to be created)
• uc501-decoder.js — standalone codec file (to be created)
• device-mapping.template.json — mapping template (to be created)
• bosch-zone-programming.md — Bosch 6000 config changes (to be created)
• handoff-template.md — final client handover doc template (to be created)

Useful references

Supplier contact list

13. Quick Build Order

Shortest path from zero to working prototype:

1. Order parts from the BOM: UC501 ×1 first for testing, UG67 ×1, Pi kit, relay board, enclosures, buttons, antennas
2. While parts are shipping: flash Pi, install Mosquitto + Node-RED on the bench
3. Configure UG67 on the bench, join it to ChirpStack built-in network server
4. Join one UC501 via NFC, watch MQTT uplinks arrive
5. Wire one e-stop button to that UC501, test end-to-end: MQTT → Node-RED → GPIO → multimeter on relay
6. Wire to a test Bosch panel (or the CM705B expander from the actual job), verify zone fires
7. Once one works, order the remaining 6 UC501s + enclosures, build in parallel
8. Full bench test all 7 with the testing protocol in section 9
9. Deploy to site using the deployment notes in section 10

Version History