Shelly Door/Window 2

Packet Parser → MQTT

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Last updated: 03. 2026

Shelly Door/Window 2 Product Page

The Shelly Door/Window 2 (SHDW-2) is a battery-powered (2x CR123A) Wi-Fi contact sensor. TapHome communicates with the device over MQTT — the recommended protocol for battery-operated Shelly devices, since the sensor sleeps most of the time and publishes data only on wake-up events (magnet state change, vibration, brightness change, or periodic timer).

The template supports up to 5 Shelly Door/Window sensors per module. Each sensor instance is distinguished by a sensorN_topic custom variable pointing to the device’s MQTT Client ID.

Configuration

Device ID

Each Shelly Door/Window 2 sensor has a unique MQTT Device ID in the format shellydw2-<MAC6>, where <MAC6> is the last 6 characters of the MAC address in lowercase hex (e.g., shellydw2-A1B2C3).

The Device ID can be found:

On the device label (MAC address)
In the Shelly web UI: Settings → Device Info
Via API: GET http://<device-ip>/settings → device.hostname field

This device supports mDNS discovery. You can use the hostname shellydw2-{MAC}.local instead of an IP address when configuring TapHome. Replace {MAC} with the last 6 characters of the device’s MAC address in lowercase hex (e.g., shellydw2-A1B2C3.local). Using a hostname prevents connectivity issues when the device’s IP address changes.

Template setup

After importing the template in TapHome:

Open the Shelly Door/Window MQTT module
Set the MQTT Broker IP and Port (default 1883)
For each sensor instance, set the sensorN_topic custom variable to the Device ID of the corresponding Shelly Door/Window 2 (e.g., shellydw2-A1B2C3)

The module subscribes to shellies/# and the listener scripts filter messages by the configured topic prefix.

Only configure the sensor slots you actually use. Unconfigured slots (with the default shellydw2-deviceid value) will show an error message prompting you to set the correct topic.

Device capabilities

Open/close detection

Each sensor instance is mapped as a Reed Contact device in TapHome. The door/window state is read from the shellies/<id>/sensor/state topic:

open → Alarm (door/window open)
close → OK (door/window closed)

The sensor wakes up and publishes its state when the magnet moves (door or window opens or closes), and also during periodic reporting intervals (default every 3 minutes).

Battery, temperature and luminance monitoring

Each sensor instance exposes three service attributes:

Battery — battery level percentage read from shellies/<id>/sensor/battery. A low battery warning is triggered when the level drops below 20%.
Temperature — ambient temperature in °C read from shellies/<id>/sensor/temperature.
Luminance — ambient light level in lux read from shellies/<id>/sensor/lux.

All attributes are read-only and update whenever the sensor wakes up and publishes data.

Additional capabilities (not implemented)

The Shelly Door/Window 2 also publishes tilt angle (0–180 degrees) and vibration detection via MQTT, as well as an online/offline status via the LWT topic. These capabilities are available in the device’s MQTT output but are not mapped in the current TapHome template. They can be added in a future template update.

Troubleshooting

Sensor not reporting data

Verify the Shelly Door/Window 2 is connected to Wi-Fi and MQTT is enabled in the device settings
Check that the sensorN_topic custom variable matches the Device ID exactly (e.g., shellydw2-A1B2C3)
If the MQTT broker address changed, try using the mDNS hostname (shellydw2-A1B2C3.local) to verify the sensor is reachable on the network
Use an MQTT client (e.g., MQTT Explorer) to subscribe to shellies/# and verify the sensor publishes messages on wake-up

Open/close state not updating

Make sure the magnet is properly aligned with the main unit — when the door/window is closed, the magnet should be within 15 mm of the sensor
If the sensor was recently moved, use the calibration endpoint (GET http://<device-ip>/calibrate?opened=1) with the door/window in the open position to recalibrate
Check TapHome for the Reed Contact device state — 1 = open (alarm), 0 = closed (OK)

Battery draining quickly

Shelly Door/Window 2 uses 2x CR123A batteries (not rechargeable) with typical battery life of approximately 18 months
Frequent wake-ups (e.g., due to unstable Wi-Fi requiring repeated reconnection or a very short sleep period) can drain the battery faster
The default sleep period is 3 minutes — increasing it via sleep_mode.period in the device settings reduces power consumption
Ensure strong Wi-Fi signal at the sensor location

Gen1 Shelly devices do not support MQTT over TLS. Communication between the sensor and the MQTT broker is unencrypted (plain MQTT, port 1883). Ensure the MQTT broker is on a trusted local network.

How to install in TapHome

Prerequisites

Shelly device connected to Wi-Fi (see HTTP connection guide if not done yet)
MQTT broker running on your local network (e.g., Mosquitto, Home Assistant, or TapHome built-in broker)
TapHome CCU on the same network as the broker

On Gen1 devices, enabling MQTT disables Shelly Cloud. Both cannot run simultaneously. On Gen2/Plus devices this limitation does not apply.

Step 1 — Enable MQTT on the Shelly device

Gen1 devices (Shelly 1, 1PM, 2.5, EM, 3EM, Plug S, RGBW2, Dimmer, TRV…)

Open the Shelly web UI: http://<device-ip>/
Navigate to Internet & Security → Advanced — MQTT
Enable MQTT
Set MQTT Server: <broker-ip>:<port> (e.g., 192.168.1.10:1883)
Optionally set MQTT User and MQTT Password if your broker requires authentication
Click Save — the device will reboot and connect to the broker

Gen2 / Plus devices (Shelly Plus 1, Plus 1PM, Plus 2PM, Plus Plug S, Plus H&T, Pro 3EM…)

Open the Shelly web UI: http://<device-ip>/
Navigate to Settings → MQTT
Enable MQTT
Set Server: <broker-ip>:<port> (e.g., 192.168.1.10:1883)
The Client ID is pre-filled with the device ID (e.g., shellyplus1pm-AABBCCDDEE) — leave as-is unless you have a specific reason to change it
Click Save and reboot the device

To verify MQTT is working, use an MQTT client (e.g., MQTT Explorer) and subscribe to shellies/# (Gen1) or <device-id>/# (Gen2). You should see status messages from the device.

Step 2 — Find the Device ID / MQTT Client ID

Some templates require a Device ID or MQTT Client ID parameter. This is the unique identifier used in MQTT topics.

Gen1: found on the label as MAC address (e.g., AABBCCDDEE). Device ID = shelly<model>-<mac>, e.g., shelly1pm-AABBCCDDEE
Gen2/Plus: found in the Shelly web UI under Settings → Device Info → Device ID, or on the device label

Step 3 — Configure in TapHome

In TapHome, add a new Packet Parser (MQTT) module
IP Address: enter the MQTT broker IP (e.g., 192.168.1.10)
Port: 1883 (default; use 8883 for TLS)
Device ID / MQTT Client ID: enter the value from Step 2 (if required by the template)
Import the template — TapHome will subscribe to the device topics automatically

Available devices

Shelly Door/Window MQTT Module

Custom Variables

`sensor1_topic` (string) = shellydw2-deviceid	MQTT device ID of door/window sensor 1 — format is 'shellydw2-DEVICEID' (find Device ID in Shelly web UI → Settings → Device Info) Open http://shellyIpAddress → Settings → Device info → copy Device ID. Format: shellydw2-<last6MAC>
`sensor2_topic` (string) = shellydw2-deviceid	MQTT device ID of door/window sensor 2
`sensor3_topic` (string) = shellydw2-deviceid	MQTT device ID of door/window sensor 3
`sensor4_topic` (string) = shellydw2-deviceid	MQTT device ID of door/window sensor 4
`sensor5_topic` (string) = shellydw2-deviceid	MQTT device ID of door/window sensor 5

Door/Window Sensor 1 Reed Contact Read-only

Open/close detection via reed switch — reports alarm when door/window is open, OK when closed

boolean

Service Attributes

Battery

Temperature

Luminance

Door/Window Sensor 1

Listener

IF (INDEXOF(sensor1_topic, "shellydw2-deviceid") = 0)
    ADDERROR("Set correct 'sensor1_topic' value in module variables. Topic format is 'shellydw2-<deviceid>'. The Device ID can be found by opening url 'http://shellyIpAddress', in Settings -> Device info.");
    RETURN(-1);
END

VAR topicPrefix := "shellies/" + sensor1_topic;

IF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/state") = 0)
    VAR value := TOSTRING(RECEIVEDMSG.PAYLOAD);

    IF (COMPARE(value, "open", CompareOptions.IgnoreCase) = 0)
        Rc := 1;
    ELSEIF (COMPARE(value, "close", CompareOptions.IgnoreCase) = 0)
        Rc := 0;
    ELSE
        Rc := NaN;
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/temperature") = 0)
    temp := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/battery") = 0)
    battery := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
    IF battery < 20
        ADDWARNING("Battery low (" + battery + "%)");
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/lux") = 0)
    luminance := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
END

Service Attributes

Battery

battery + "%"

Temperature

temp + "°C"

Luminance

luminance + " lux"

Door/Window Sensor 2 Reed Contact Read-only

Open/close detection via reed switch — reports alarm when door/window is open, OK when closed

boolean

Service Attributes

Battery

Temperature

Luminance

Door/Window Sensor 2

Listener

IF (INDEXOF(sensor2_topic, "shellydw2-deviceid") = 0)
    ADDERROR("Set correct 'sensor2_topic' value in module variables. Topic format is 'shellydw2-<deviceid>'. The Device ID can be found by opening url 'http://shellyIpAddress', in Settings -> Device info.");
    RETURN(-1);
END

VAR topicPrefix := "shellies/" + sensor2_topic;

IF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/state") = 0)
    VAR value := TOSTRING(RECEIVEDMSG.PAYLOAD);

    IF (COMPARE(value, "open", CompareOptions.IgnoreCase) = 0)
        Rc := 1;
    ELSEIF (COMPARE(value, "close", CompareOptions.IgnoreCase) = 0)
        Rc := 0;
    ELSE
        Rc := NaN;
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/temperature") = 0)
    temp := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/battery") = 0)
    battery := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
    IF battery < 20
        ADDWARNING("Battery low (" + battery + "%)");
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/lux") = 0)
    luminance := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
END

Service Attributes

Battery

battery + "%"

Temperature

temp + "°C"

Luminance

luminance + " lux"

Door/Window Sensor 3 Reed Contact Read-only

Open/close detection via reed switch — reports alarm when door/window is open, OK when closed

boolean

Service Attributes

Battery

Temperature

Luminance

Door/Window Sensor 3

Listener

IF (INDEXOF(sensor3_topic, "shellydw2-deviceid") = 0)
    ADDERROR("Set correct 'sensor3_topic' value in module variables. Topic format is 'shellydw2-<deviceid>'. The Device ID can be found by opening url 'http://shellyIpAddress', in Settings -> Device info.");
    RETURN(-1);
END

VAR topicPrefix := "shellies/" + sensor3_topic;

IF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/state") = 0)
    VAR value := TOSTRING(RECEIVEDMSG.PAYLOAD);

    IF (COMPARE(value, "open", CompareOptions.IgnoreCase) = 0)
        Rc := 1;
    ELSEIF (COMPARE(value, "close", CompareOptions.IgnoreCase) = 0)
        Rc := 0;
    ELSE
        Rc := NaN;
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/temperature") = 0)
    temp := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/battery") = 0)
    battery := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
    IF battery < 20
        ADDWARNING("Battery low (" + battery + "%)");
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/lux") = 0)
    luminance := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
END

Service Attributes

Battery

battery + "%"

Temperature

temp + "°C"

Luminance

luminance + " lux"

Door/Window Sensor 4 Reed Contact Read-only

Open/close detection via reed switch — reports alarm when door/window is open, OK when closed

boolean

Service Attributes

Battery

Temperature

Luminance

Door/Window Sensor 4

Listener

IF (INDEXOF(sensor4_topic, "shellydw2-deviceid") = 0)
    ADDERROR("Set correct 'sensor4_topic' value in module variables. Topic format is 'shellydw2-<deviceid>'. The Device ID can be found by opening url 'http://shellyIpAddress', in Settings -> Device info.");
    RETURN(-1);
END

VAR topicPrefix := "shellies/" + sensor4_topic;

IF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/state") = 0)
    VAR value := TOSTRING(RECEIVEDMSG.PAYLOAD);

    IF (COMPARE(value, "open", CompareOptions.IgnoreCase) = 0)
        Rc := 1;
    ELSEIF (COMPARE(value, "close", CompareOptions.IgnoreCase) = 0)
        Rc := 0;
    ELSE
        Rc := NaN;
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/temperature") = 0)
    temp := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/battery") = 0)
    battery := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
    IF battery < 20
        ADDWARNING("Battery low (" + battery + "%)");
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/lux") = 0)
    luminance := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
END

Service Attributes

Battery

battery + "%"

Temperature

temp + "°C"

Luminance

luminance + " lux"

Door/Window Sensor 5 Reed Contact Read-only

Open/close detection via reed switch — reports alarm when door/window is open, OK when closed

boolean

Service Attributes

Battery

Temperature

Luminance

Door/Window Sensor 5

Listener

IF (INDEXOF(sensor5_topic, "shellydw2-deviceid") = 0)
    ADDERROR("Set correct 'sensor5_topic' value in module variables. Topic format is 'shellydw2-<deviceid>'. The Device ID can be found by opening url 'http://shellyIpAddress', in Settings -> Device info.");
    RETURN(-1);
END

VAR topicPrefix := "shellies/" + sensor5_topic;

IF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/state") = 0)
    VAR value := TOSTRING(RECEIVEDMSG.PAYLOAD);

    IF (COMPARE(value, "open", CompareOptions.IgnoreCase) = 0)
        Rc := 1;
    ELSEIF (COMPARE(value, "close", CompareOptions.IgnoreCase) = 0)
        Rc := 0;
    ELSE
        Rc := NaN;
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/temperature") = 0)
    temp := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/battery") = 0)
    battery := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
    IF battery < 20
        ADDWARNING("Battery low (" + battery + "%)");
    END
ELSEIF (INDEXOF(RECEIVEDMSG.TOPIC, topicPrefix + "/sensor/lux") = 0)
    luminance := TODOUBLE(TOSTRING(RECEIVEDMSG.PAYLOAD));
END

Service Attributes

Battery

battery + "%"

Temperature

temp + "°C"

Luminance

luminance + " lux"

Connection: Packet Parser → MQTT

Possible improvements (4)

Tilt Angle — Tilt angle in degrees (0-180), DW2 only. Available in MQTT but not mapped in the TapHome listener script.
Vibration Detection — Vibration detection (0=none, 1=detected). Configurable sensitivity (high/medium/low). Available in MQTT but not mapped in the TapHome listener script.
Connection Status — LWT topic — true on connect, false on disconnect. Could detect offline sensors.
Full Status JSON — Complete /status as JSON (fw >=1.8.0). Could parse wifi_sta.rssi, battery, act_reasons.

Download Template

Sources

Shelly Gen1 API Reference
shelly-api-docs.shelly.cloud 2026-03-12
Home Assistant Shelly Integration
www.home-assistant.io 2026-03-12
Shelly Door/Window 2 — Device-Specific API
shelly-api-docs.shelly.cloud 2026-03-30
Shelly Door/Window 2 — Knowledge Base
kb.shelly.cloud 2026-03-30