Introducing the **Presence Sensor DIY Board**, a **compact yet highly functional** design that is easy to assemble with minimal components. Despite its simplicity, it provides **robust presence detection capabilities**, making it suitable for a wide range of applications.  

Key Features:

1. mmWave Sensor Compatibility

- Designed for use with **DFRobot mmWave sensor modules** such as **SEN0609 and SEN0395**.  

- Compatible with other sensors that share a similar **pinout**.  

- **Recommended Sensor:** The **SEN0609** is suggested based on feedback from DFRobot officials, as it offers **better performance, enhanced features, and a more affordable price** compared to SEN0395.  

2. Optional PIR Sensor Support

- The board includes a dedicated slot for a **PIR sensor**, providing an additional layer of **presence detection filtering**.  

- **Why add PIR?**  

 - **DFRobot mmWave sensors** are highly reliable, but in certain environments (e.g., offices), **false positives** may occur.  

 - A **PIR sensor** can help refine detection accuracy in such cases.  

- **Recommended PIR Sensors:** While generic PIR sensors are available, **Panasonic PIR sensors** offer superior performance and reliability.  

3. Integrated TSL25911 Light Sensor  

- The **TSL25911** is a **high-sensitivity ambient light sensor**, allowing for:  

 - **Accurate light level detection** even when enclosed in a case.  

 - **Seamless automation** based on ambient lighting conditions.  

- If you are planning to integrate **light-based automation**, this sensor is a must-have.  

4. Temperature Sensor Considerations

- While a **temperature sensor** can be placed on the PCB, it may be affected by heat from the **ESP32-S3 mini** and **mmWave sensors**, leading to inconsistent readings.  

- **Recommended Approach:**  

 - Instead of an onboard sensor, use an **external temperature sensor** via the **onboard STEMMA QT connector** for more accurate results.  

5. Dual STEMMA QT Connectors for Extended I2C Support

- The board features **two STEMMA QT connectors**, each connected to a **separate I2C bus**.  

- **Benefits of dual I2C lines:**  

 - Expands compatibility with a **wide range of STEMMA QT-enabled sensors**.  

 - Supports specialized modules, such as **WeAct I2C OLED displays**, which require **swapped I2C lines**.  

6. Onboard LED Indicators for Enhanced Usability

- Several **onboard LEDs** provide real-time feedback:  

 - **ESP32-S3 Status Indicator** – Shows the current system state.  

 - **Power Indicator** – Confirms power presence.  

 - **RGB LED** – Can be customized to indicate **presence detection status or other signals**.  

- **User Control:** All LEDs are **software-controllable**, allowing you to disable them if not required.  

NB. Please see the attached iBOM file for help with the assembly.

It can be programmed via the USB-C port.