Connecting the 3-way sensor

A small puck-shaped sensor that hangs in your tent canopy and measures temperature, humidity, and pressure all at once — that's the "3-way". Plugs into the Nexus via a single keyed cable. About 60 seconds to plug in.

Technical illustration of the BudMaster 3-way sensor pod connecting to the Nexus via a fabric-sleeved cable. The pod is shown with a green status LED. The cable terminates in a white keyed plug seating into the Nexus sensor port, with a 'click' flash flag at the moment of insertion. A stylised tent silhouette on the left shows the pod hanging mid-canopy. Callouts label the keyed tab orientation, the click moment, the LED verification, and a reminder to fit the strain-relief grommet first.

Keyed plug · push until click · Plugs into the Nexus sensor port

Before you start

The Nexus is wired and powered (see wiring + first setup guides).
You've got the sensor pod and its 600 mm fabric-sleeved cable terminated in a keyed plug. Both ship in the BudMaster kit.

What's in the pod

A small disc-shaped enclosure, ~50 mm diameter × 14 mm thick, BudMaster-green with a brushed-finish lid.

Air temperature ±0.3 °C · factory calibrated

Relative humidity ±2 % RH · factory calibrated

Barometric pressure ±1 hPa (altitude-compensated VPD)

Status LED Green pulse on connect · amber flash on read errors

The pod is fully sealed (IP54-equivalent against canopy moisture splash). Don't immerse it. The cable's strain-relief gland is also sealed — the only thing you handle is the keyed plug at the Nexus end.

The connection

The plug is keyed — it only fits one way. There's a small tab on one side of the connector that matches a slot in the Nexus sensor port. If you have to force it, you've got it upside down.

Find the Nexus sensor port — a keyed socket on the side of the hub, labelled SENSOR in white silkscreen. Every sensor lives on this one port.
Hold the plug with the keyed tab facing up — the tab is the small ridge on one side of the white plastic body.
Push the plug straight in until you feel and hear a small click. The plug is fully seated when the white plastic is flush with the hub body.
Tug-test gently — the plug should hold firm with the locking spur engaged. If it pops out, it wasn't fully seated.
Watch the pod's status LED — it pulses green once within ~2 seconds, confirming the Nexus has found the sensor. If it flashes amber instead, see Common Mistakes below.

That's the wiring. The Nexus auto-detects the pod on boot and starts reading temp / humidity / pressure within 5 seconds of power-up.

Where to mount the pod

Mid-canopy. That's the rule. The pod measures whatever air it's sitting in — and the air at canopy level is the air your plants are actually breathing.

Don't mount the pod:

At the top of the tent — too hot, too dry, doesn't reflect plant-level conditions
At the floor — too humid, too cool
Right next to the extract fan — measures the airflow, not the room
Right under the LED — radiant heat skews the temperature reading high

Do mount it:

At the height of the topmost colas — for flower stage, this is mid-canopy. Adjust as plants grow.
In the centre of the tent — equidistant from walls and corners.
Hanging from a clip or hook, not pressed against a leaf — leaf surfaces hold moisture and skew RH.

Cable length: 600 mm — long enough to reach from the Nexus (mounted outside the tent) through the tent's port and down to canopy height in a 4×4 ft tent. Larger tents may need an extension cable (sold separately, keyed male-to-female, ~1 m).

Verify it's reading

Open budmaster.local on your phone.
The dashboard's top header should now show live readings: Temp / RH / Pressure / VPD.
Numbers should look reasonable for your tent (e.g. 24 °C, 60 % RH, 1013 hPa, 1.2 kPa VPD for a Flower-stage tent at sea level).
Wave a hand near the pod — you should see the temperature tick up by ~0.2 °C within a few seconds. Confirms the readings are live, not cached.

If the dashboard shows -- / -- / -- for the readings, the Nexus isn't seeing the pod. See Common Mistakes.

Common mistakes

Mistake	Symptom	Fix
Plug not fully seated	Pod LED stays dark, dashboard reads `--`	Push plug in firmly until click. The locking spur should be visibly engaged.
Plug forced upside-down (keyed tab the wrong way)	Plug bent / damaged pins	Inspect pins. If bent, gently straighten with tweezers. If broken, ask us for a replacement cable.
Pod mounted right under the LED	Temp reads 6+ °C above realistic	Move the pod to mid-canopy, away from direct radiant heat
Pod mounted next to extract fan	RH reads suspiciously stable, doesn't track tent state	Move to centre of tent at canopy height
Cable strung tight	Strain on the plug pulls it loose intermittently	Add ~50 mm slack at the Nexus end; route through the tent's strain-relief grommet (don't forget to thread it onto the cable BEFORE termination)
Pod LED flashes amber repeatedly	Sensor read error (loose plug, damaged cable, hub fault)	Power-cycle the Nexus. If error persists, swap to a known-good cable. If it STILL persists, contact support.
Two pods plugged in (daisy-chain) but only one shows	Sensor address conflict	Each daisy-chained pod needs a different address — set via the small jumpers on the back. See multi-pod guide.

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