The Adafruit SHT41 Trinkey is a hybrid USB key and temperature-humidity sensor, designed for effortless integration with any USB A port on a computer. With this device, users can easily access one of our top-rated environmental sensors.

The PCB is specifically designed to fit into any USB A port on a computer or laptop. Utilizing an ATSAMD21 microcontroller, it contains the necessary circuitry for optimal functionality. One of the microcontroller's pins connects to NeoPixel LEDs, while another is designated for a capacitive touch input on the end. Additionally, a reset button allows for easy access to bootloader mode if needed.

The SAMD21 can run CircuitPython or Arduino very nicely - both have existing SHT4x, NeoPixel and our FreeTouch (capacitive touch) libraries. Over the USB connection, you can have serial, MIDI, or HID connectivity.

The star of this Trinkey is the . Sensirion Temperature/Humidity sensors are some of the finest & highest-accuracy devices you can get. The SHT41 sensor is the fourth generation of I2C temperature and humidity sensor from Sensirion. (They started at the SHT10 and reached the top!). The SHT41 has an excellent ±1.8% typical relative humidity accuracy from 25 to 75% and ±0.2 °C typical accuracy from 0 to 75 °C. Note that the reported temperature may be a few degrees higher than ambient due to self-heating.

The SHT41 Trinkey is perfect for simple projects that want to read the ambient temperature and humidity without any extra wiring, soldering, drivers, or complex software. In fact we even ship the board pre-programmed with code that will print a unique serial number, the temperature, humidity and touch sensor over a serial/COM port in CSV (comma separated value) format, so you can use it immediately.  .

which has ±1.0% typical relative humidity accuracy from 25 to 75% and ±0.1°C typical accuracy from 0 to 75 °C.

We think it's just an adorable little board, small and durable and inexpensive enough that it could be a first microcontroller board or inspiration for advanced developers to make something simple and fun.

• ATSAMD21E18 32-bit Cortex M0 - 48 MHz 32 bit processor with 256KB Flash and 32 KB RAM
• Native USB supported by every OS - can be used in Arduino or CircuitPython as USB serial console, MIDI, Keyboard/Mouse HID, even a little disk drive for storing Python scripts.
• Can be used with Arduino IDE or CircuitPython
• One RGB NeoPixel LED
• One Capacitive Touchpad
• SHT41 Temperature Humidity sensor with thermal-isolation cutout
• Reset switch for starting your project code over or entering bootloader mode
• Slim and cute, keychain-friendly!