Typically used for
Sensor data
Temperature
Humidity
Appliances
Scene activation
Key Features
Dual connectivity
USB-C powered for safe and easy 5 V installation in any environment
Built-in Bluetooth Gateway for nearby device communication
Shelly Gen3 functionality with local actions, scripting, and virtual components for full automation control
Sensor reader for temperature, humidity, and environmental data with cloud logging and statistics
Advanced automation and integration via MQTT, WebSocket, HTTP, and virtual devices
Expandable design through add-ons for digital I/O, analog sensing, and high-accuracy voltage measurement
Configurable peripheral modes supporting a broad range of external modules and extensions
High-accuracy analog measurement for reading DC voltages up to 30 V with the external add-on
Three configurable digital I/Os for direct logic-level control and system interfacing
Device identification
Device name: The Pill by Shelly
Device model: S3SN-0U53X
Device SSID: ShellyPill-XXXXXXXXXXXXXX
Bluetooth ID: 0x1829
Short description
The Pill by Shelly is a compact multi-purpose low-voltage Wi-Fi & Bluetooth device, powered by only 5V via USB-C. The small form factor allows it to fit conveniently into any space-constraint environment.
The device is ready to use for Temperature monitoring with Plug and play compatibility with external Temperature sensors (DS18B20) or Temperature & Humidity (DHT22). Additionally, supporting wide variety of digital or analog sensors and low-voltage actuators with external peripheral addons and configurable peripheral modes.
Main features
Compact design
USB-C powered (5V)
Dual connectivity (WiFi & Bluetooth)
Plug and play: Temperature monitoring (DS18B20/DHT22)
Advanced peripheral modes - Digital Input/Output; Analog input (Voltage meter);
External Peripheral Add-ons: SSR Dual-channel, Analog Voltage measurement (0-30V)
Shelly Gen3 capabilities (Local actions, Schedules, Scripting, Virtual components)
Bluetooth Gateway for Shelly BLU devices
3rd party integrations-ready (MQTT, WebSocket, HTTP)
Peripheral modes
Temperature (DS18B20) - Supporting up to 5 x Temperature probes (DS18B20); + optional 2 Digital IO
Temperature & Humidity - 1x Temperature & Humidity sensor DHT22 + optional 2 Digital IO
Analog Input - Analog sensor input (voltmeter) + optional Digital IO. Measured Voltages: 0-2.5 V (default); external Add-on for 0-30V
Digital Input/Output - configurable for up to 3x Inputs/Outputs ; Digital IO: 3.3 V Logic Levels; Digital input: Active Low (default).
Solid State Relay Add-on - Peripheral Addon with 2x channels galvanic-isolated outputs (max 30 V / 300 mA) + optional Digitial IO
* Note: Digital I/O can be combined with all modes and setup independently as Input or Output
Use cases
Water Temperature Monitoring
Track temperature of pools, aquariums, water tanks and reservoirs with simultaneous monitoring of up to five temperature points, using external temperature sensor probes (DS18B20)Temperature and Humidity Monitoring
Monitor temperature and humidity in a room, server cabinets, greenhouse, warehouses or other areas where keeping optimal environment condition is necessary, with the supported external sensor DHT22Digital Sensors Readings
Connect simple digital sensors like door reed, motion, water state sensor to your home automation systemDC Voltage monitoring - external Add-on available
Monitor DC voltages up to 30 V with the external Analog 0-30 V Add-on, suitable for tracking voltage across various battery systems (3.7 V, 12 V, 24 V) or other DC power lines.Analog Sensor measurements - external Add-on available
Analog sensor voltage measuring for popular hobby & industrial analog sensors with the available Analog 0-30 V Add-onControl DC Loads - external Add-on available
Dual-channel control for small DC Loads up to 30 V / 300 mA like led indicators, small fans, solenoids, valves and etc. with additionally available external SSR Add-onExternal Systems Control
Available Digital Input/Outputs allow switching and reading state of external controllers and systems (3.3V logic level). The optionally available SSR Add-on allows triggering inputs of external controllers (max 30 V / 300 mA).
Main applications
Residential
University/college
Hobby
Integrations
…

Device electrical interfaces
Power supply
USB-C power supply: +5 V⎓
Add-on interface
DC Power Supply: +5 V⎓
Input/Output 1 - Configurable:
1-Wire (DS18B20, DHT22)
Digital Input
Digital Output
Analog Input (Voltmeter)
Input/Output 2 - Configurable:
Digital Input
Digital Output
Input/Output 3 - Configurable:
Digital Input
Digital Output
GND
Connectivity and protocols
Wi-Fi
Bluetooth
User interface
Inputs
One (Control) button
Press and hold for 5 seconds to enable Device access point and Bluetooth connection.
Press and hold for 10 seconds to factory reset the Device.
Outputs
LED (monocolor) indication
AP (Access Point) enabled and Wi-Fi disabled:
1 second ON / 1 second OFFWi-Fi enabled, but not connected to a Wi-Fi network:
1 second ON / 3 seconds OFFConnected to a Wi-Fi network:
Constantly ONCloud is enabled, but not connected:
1 second ON /5 seconds OFFConnected to Shelly Cloud:
Constantly ONOTA (Over the Air Update):
½ sec ON / ½ second OFFButton pressed and held for 5 seconds:
½ second ON / ½ second OFFButton pressed and held for 10 seconds:
¼ second ON / ¼ second OFF
The list above starts with the initial device status and the lowest priority. Every next state cancels the previous one.
Quantity | Value |
|---|---|
Physical | |
Size (HxWxD): | 26 x 19.95 x 8.5 mm / 1.02 x 0.79 x 0.34 inch |
Weight: | 3 g / 0.11 oz |
Shell material: | Plastic |
Shell color: | White |
Environmental | |
Ambient working temperature: | -20 to 40 °C / -5 to 105 °F |
Humidity: | 30 % - 70 % RH |
Electrical | |
Power supply: | 5 V⎓ (from USB Type-C port) |
Power consumption: | < 1 W |
Input circuits ratings | |
Digital inputs triggering voltage: | Active LOW; Trigger low: < 0.83 V Trigger high: > 2.48 V |
Digital inputs max. voltage | 3.3 V |
Output circuits ratings | |
Max. switching voltage: | 3.3 V (logic-level) |
Max. switching current: | 20 mA |
Sensors, meters | |
Voltmeter (DC) |
|
Voltmeter accuracy: | ±(2% + 5d) |
Internal-temperature sensor: | No |
External sensors supported: |
|
Radio | |
Wi-Fi | |
Protocol: | 802.11 b/g/n |
RF band: | 2401 - 2483 MHz |
Max. RF power: | < 20 dBm |
Range: | Up to 30 m / 100 ft indoors and 50 m / 160 ft outdoors (Depends on local conditions) |
Bluetooth | |
Protocol: | BLE 4.2 |
RF band: | 2402 - 2480 MHz |
Max. RF power: | < 10 dBm |
Range: | Up to 10 m / 33 ft indoors and 30 m / 100 ft outdoors |
Microcontroller unit | |
CPU: | Shelly ESP32 C3 (ESP-Shelly-C38F) |
Flash: | 8MB |
Firmware capabilities | |
Schedules: | 20 |
Webhooks (URL actions): | 20 with 5 URLs per hook |
Scripting: | Yes |
MQTT: | Yes |
Encryption: | Yes |
Other: | Supported Accessories:
Supported add-ons:
|
What are the differences between the different generations of Shelly products?
Each new generation adds more power, memory, and features:
Gen 1 offers basic control;
Gen 2 (Plus Series, Mini Series, Pro Series) adds Bluetooth, scripting, and better security;
Gen 3 improves performance, adds Matter (starting from firmware version 1.6.0 or newer) and advanced monitoring;
Gen 4 offers multi-protocol connectivity, featuring Wi-Fi 6, Bluetooth, Zigbee, and Matter.
Can I control the device via Bluetooth?
No, the protocol is used only for device inclusion, allowing for quick and easy setup through the Shelly Smart Control app.
For bluetooth control it is required to have another Bluetooth device such as Shelly BLU Button or Shelly BLU Motion to interact.
Additionally, Shelly devices can function as a BLE gateway, bridging Shelly BLU devices to your Wi-Fi network.
Is it possible to use the device without a hub?
Yes, Shelly devices (except for Wave devices) operate independently without the need for a hub. They connect directly to your Wi-Fi network, and you can control them via the Shelly Smart Control app, web interface, or through integrations with platforms like Google Home, Alexa, Home Assistant and Samsung SmartThings.
Use cases
Water Temperature Monitoring
Monitor aquariums, pools, boilers, water tanks, or other liquids with precise temperature readings. The Pill by Shelly connects to your water temperature sensors and sends real-time data to the Shelly Smart Control app.
Air & Greenhouse Climate Monitoring
Whether you're maintaining a healthy indoor environment or creating optimal conditions for plant growth, The Pill by Shelly delivers accurate temperature and humidity data using the DS18B20 or DHT22 sensors.
Voltage Monitoring for Battery Systems
In small battery-powered setups, even slight voltage changes can affect performance and reliability.
Flexible Automation for Unique Setups
Every smart setup has its own logic, and with The Pill by Shelly, you can build yours exactly the way you want it.







