Shelly Plus Smoke web interface guide
To connect to your Shelly Plus Smoke, connect your device to the Wi-Fi network with a name(SSID) like ShellyPlusSmoke - 84CCA87D7CDC. Use the universal IP address for all Shelly devices - 192.168.33.1 to access your device's Web Interface, where you can set a Wi-fi network for the Shelly Plus Smoke to connect to.

General - Home page
In the web interface, you will see five icons at the top of the screen, including one for AP, Wi-Fi, Bluetooth, Cloud and MQTT connection. Here is what the different status colors mean:
AP icon:
Gray: AP mode is disabled.
Blue: AP mode is enabled.
Wi-Fi icon:
Gray: Wi-Fi connection is disabled.
White: Wi-Fi connection is enabled, but not established.
Blue: Device is connected to Wi-Fi.
Bluetooth icon:
Gray: Connection is disabled.
Blue: Connection is enabled.
Cloud icon:
Gray: Connection to Shelly Cloud is disabled.
White: Connection to Shelly Cloud is enabled, but not established.
Blue: Device is connected to Shelly Cloud.
MQTT icon:
Gray: MQTT is disabled.
Blue: MQTT is enabled.
This page will also display the state of the smoke sensor (whether smoke has been detected or not), which can be either ON (smoke has been detected) or OFF (smoke hasn’t been detected). Underneath, the battery percentage of your Shelly Plus Smoke can tell you when the device is running low on power.
Settings
Network settings
Access Point - Configure the device's AP, including switching it on or off, and setting a password. The access point of the device is an open network by default. The SSID is unique and cannot be changed.
WiFi - Register the Shelly device to connect to up to 2 different Wi-Fi networks.
Either input or select the Wi-Fi network. Can select an open network, and also set a static IP address.
Enable Wi-Fi 1, or Wi-Fi 2, or both at the same time. If both Wi-Fi 1 and Wi-Fi 2 are enabled, and the Shelly device disconnects from one of the networks, it will connect to the other.
Bluetooth - Disable/enable Bluetooth by toggling the switch. The device's default Bluetooth setting is enabled.
Connectivity
Cloud -Connecting your Shelly to its cloud allows you to control it remotely, receive notifications and updates about your devices. The default for this setting is for the cloud to be enabled. If you disable the device cloud support, you will lose connection to your device from outside its local network!
MQTT - Configure the Shelly device to execute actions via MQTT. By default, MQTT is disabled, but you can enable it by toggling the switch. Changing these settings will cause the device to reboot. There are some other settings, such as RPC status notifications over MQTT (which enables you to communicate with your device through RPC notifications) and Generic status update over MQTT (to get an overall status update), which you can enable/disable by toggling the switches on their right. You can also enable SSL and type in your server, username and password, but be aware that enabling SSL will hurt the battery life and most likely shorten it by half.
Outbound Websocket - Specifies whether the HTTP channel creates an I/O exception when an inbound connection is closed while still in use by the servlet. By default, this setting is disabled. To enable it, click the toggle switch next to Enable. Enter your service address in the text box and from the drop-down menu under SSL Connectivity choose *, ca.pem or user_ca.pem.
Device settings
Device info - See your device’s ID, the Wi-Fi it’s connected to and the Wi-Fi RSSI.
Location and timezone - Your timezone and location will be autodetected, but you can manually change them from this setting by choosing a timezone from the drop-down menu and typing in your latitude and longitude. There is also a button Auto detect location, which will make the device automatically detect the location once again if it failed the previous time.
Authentication - If you enable authentication, you will be asked to type in a password, which you will then use to access the Web UI of the device. Once enabled, to disable it, click the toggle and enter your authentication pass once prompted.
Firmware - In this setting, you can see your device's ID, Firmware version and build ID, as well as the Web build ID. You can also see the available new versions, check for updates and easily update your device. There is also an option to upload your own firmware, however flashing devices with custom firmware irreversibly voids the device warranty.
User certificate - Upload custom SSL certificate by dragging and dropping the file or by browsing your files, which you can do by clicking the designated button.
Debug - This setting includes Mqtt, Websocket and Udp debug. To enable any of these, click the toggle switch next to the specific setting. For Udp debug you will also be asked to type in a udp address.
Diagnostics
From this setting you can download the debug logs. Enabling the debug log without a reason isn’t recommended, since your device will be slowed down and this setting will cause aging of the flash memory. If you do decide to enable it, you can also download the previous and current logs. Be aware that leaving this page will reset the logger and logged data.