OpenSENSE is a DIY wireless ambient sensor for smart home and home automation applications.

Easily measure room temperature, humidity, pressure, ambient light and UV index. 
The sensor is USB-C powered, `really tiny` and light-weight so you can easily mount it almost anywhere.

Sensor Measurements:

• Ambient Temperature
• Relative Humidity
• Barometric pressure
• Ambient Light
• UV Index

Features:

• Small form-factor (measures 40x20mm / 1.58"x0.79")
• USB-C connector for power
• Wireless sensor (WiFi)
• Low-power consumption
• Re-configurable over USB
• Works with HomeAssistant
• Works with ESPHome
• Open-Source and Open-Hardware
• DIY friendly

Hardware:

• ESP32-C3 microcontroller
  • Wi-Fi and Bluetooth 5 (LE) SoC
    
• BME280 temperature, humidity and pressure sensor
  • Temperature: -40 to +80C temperature range
  • Humidity: ±3% accuracy (20-100% RH)
  • Pressure: RMS noise 0.2Pa, Sensitivity error ±0.25%
• LTR-390UV ambient light and UV sensor
  • Wide dynamic range 1:18.000.000
  • Close to human eye spectral response

Out of the box the sensor is pre-configured to work with HomeAssistant using ESPHome integration. This should allow anyone to get up-an-running in just a couple of simple steps.
There is also a detailed step-by-step guide available in the GitHub repository in case you need it, get stuck or just curious how things work.

FAQ

Can I re-configure the sensor to do ___?

Open AmbiSense is running on ESPHome firmware. One of the coolest features of ESPHome is that it allows you to reconfigure the device without any programming.
It uses configuration files to "describe" how the device should work. Then the ESPHome will convert configuration files into code that does exactly what was prescribed in the configuration file and upload it to the device.

There are example configuration files in the official GitHub repository that you can use as a starting point.

Can I use this board with custom Arduino/ESP-IDF firmware?

Absolutely! This is essentially a custom ESP32-C3 board with BME280 and LTR-390UV sensors on board. You can load your custom Arduino/ESP-IDF firmware over USB-C connector which provides power and data to the board. The board schematic is available in the GitHub repository.

Is there documentation available?

Absolutely! You can find documentation at docs.sasakaranovic.com