The Pill by Shelly

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
…
Simplified internal schematics

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 secondON/ 1 secondOFFWi-Fi enabled, but not connected to a Wi-Fi network:
1 secondON/ 3 secondsOFFConnected to a Wi-Fi network:
ConstantlyONCloud is enabled, but not connected:
1 secondON/5 secondsOFFConnected to Shelly Cloud:
ConstantlyONOTA (Over the Air Update):
½ secON/ ½ secondOFFButton pressed and held for 5 seconds:
½ secondON/ ½ secondOFFButton presses and held for 10 seconds:
¼ secondON/ ¼ secondOFF
The list above starts with the initial device status and the lowest priority. Every next state cancels the previous one.
Specifications
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 МHz |
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 МHz |
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:
|
Components and APIs
This device
Compliance
The Pill by Shelly multilingual EU declaration of conformity 253 2025-12-11.pdf
The Pill by Shelly UK PSTI ACT statement of compliance 253 2025-12-11.pdf
The Pill by Shelly UKCA declaration of conformity 253 2025-12-11.pdf
Printed user guide
The Pill by Shelly multilingual printed user and safety guide.pdf