The Pill by Shelly is an extremely compact, multi-purpose smart accessory device that operates on low voltage (5V via USB-C) and features both Wi-Fi and Bluetooth connectivity. Thanks to its small size, it fits into tight spaces and can be installed almost anywhere, making it an ideal choice for areas with limited space, such as technical cabinets, control boxes, or DIY projects. Its range of use cases is practically limitless when a small, versatile device is needed.
By default, the device supports Plug & Play temperature and humidity measurement using external sensors (DS18B20, DHT22 – not included), but in reality, it is a much more versatile platform. With separately available accessories (5-Terminal, Analog 0–30V, SSR add-on, jack splitter), it also supports connecting various digital and analog sensors, as well as low-voltage controlled devices. Thanks to its configurable inputs and outputs, The Pill is an excellent choice for automation, measurement, and control tasks.
As part of the Shelly Gen3 platform, the device offers advanced features such as scheduling, local automations, scripting, and MQTT integration. It also functions as a BLE gateway, connecting Shelly BLU devices to the Wi-Fi network. This is a solution specifically designed for DIY enthusiasts and advanced users, offering high flexibility and extensive integration options.
Thanks to its versatility, The Pill by Shelly is suitable for a wide range of applications – from simple measurements to complex automation systems:
- Water temperature monitoring:
An ideal solution for measuring the temperature of aquariums, pools, boilers, or water tanks. Data from connected sensors is available in real time, making it easy to automate heating or circulation systems to maintain the desired temperature.
- Indoor and greenhouse climate control:
Enables continuous monitoring of temperature and humidity in living spaces or plant-growing environments. Based on the collected data, ventilation, humidification, or heating can be automated to ensure optimal conditions at all times.
- Battery system monitoring:
Especially useful in low-voltage systems where stable operation is critical. By continuously tracking voltage levels, deviations can be detected early, helping to prevent failures or performance drops.
- Custom automation solutions:
With flexible input/output configuration and scripting capabilities, virtually any custom logic can be implemented. Suitable for tailored home automation scenarios as well as smaller industrial or business control applications.
This compact device is an excellent choice for anyone looking for a customizable, reliable, and expandable solution for a wide range of monitoring and control tasks.
About the Shelly brand
Shelly is one of the most well-known smart home brands, famous for its Wi-Fi-based, hub-free devices. Its products integrate easily with systems such as Home Assistant, Google Home, or Amazon Alexa. Shelly stands out in local control, automation, and open integration options (MQTT, REST API).
Key product features
Compact size: Minimal space requirement, easy installation
USB-C power supply: 5V operation with low consumption
Wi-Fi + Bluetooth: Direct network connection and BLE device handling
Plug & Play sensor support: Compatible with DS18B20 and DHT22 sensors
Flexible I/O modes: Configurable digital and analog inputs/outputs
Expandability: Supports external add-on modules (SSR, analog measurement)
Shelly Gen3 features: Scripting, automations, and virtual components
BLE gateway: Integration of Shelly BLU devices
Smart home protocols and platform compatibility
Protocols: Wi-Fi (802.11 b/g/n), Bluetooth 4.2 (BLE)
Native platform: Shelly Smart Control
Third-party integration: MQTT, HTTP, WebSocket
Home Assistant: Full support
BLE devices: Shelly BLU compatibility
Local operation: Works without internet
Smart features
Temperature measurement: Up to 5× DS18B20 sensors
Humidity measurement: DHT22 sensor support
Voltage measurement: 0–2.5V (base), 0–30V with external module
Digital I/O: Control and monitor external devices
Automations: Local and cloud-based control
Scheduling: Weekly and complex timers
Scripting: Custom logic and behavior
Webhook support: Integration with external systems
Event log: Detailed operation history
Technical specifications
Product name: The Pill by Shelly
Model: S3SN-0U53X
Size: 26 × 19.95 × 8.5 mm
Weight: 3 g
Housing material: Plastic
Color: White
Power supply: 5 V DC (USB-C)
Power consumption: < 1 W
Digital input: Active LOW; LOW: <0.83 V, HIGH: >2.48 V
Max. digital input voltage: 3.3 V
Digital output: 3.3 V logic level
Max. switching current: 20 mA
Voltage measurement: 0–2.5 V (base), 0–30 V (with external module)
Measurement accuracy: ±(2% + 5d)
Internal temperature sensor: No
External sensors: 1× DHT22 or up to 5× DS18B20 (not included)
Wi-Fi: 802.11 b/g/n, 2.4 GHz
Wi-Fi range: max. 30 m (indoor), 50 m (outdoor)
Bluetooth: BLE 4.2
Bluetooth range: max. 10 m (indoor), 30 m (outdoor)
CPU: Shelly ESP32-C3
Flash memory: 8 MB
Schedules: max. 20
Webhook support: 20 (max. 5 URLs per hook)
Scripting: Yes
MQTT: Yes
Encryption: Yes
Operating temperature: -20°C – +40°C
Humidity: 30–70% RH
Supported accessories: 3.5 mm jack cable (included), 1→5 splitter, DS18B20 sensor
Supported add-ons: 5-terminal add-on, SSR add-on, 0–30V analog add-on
