StackFlex is a microcontroller system built around the Espressif ESP32-S3 Mini module. The heart of the system is the Core PCB, which houses the microprocessor and supports power delivery via USB or a LiPo battery. Additional functionalities can be seamlessly integrated through modular Feature PCBs, which are designed to stack on top of the Core PCB.

The StackFlex system is highly extensible and flexible, all within a compact 40 mm x 40 mm form factor. Leveraging the advanced capabilities of the ESP32-S3 — such as Bluetooth LE, WiFi, and more — the innovative stacking mechanism, and templates for custom Feature PCBs, the system offers virtually unlimited use cases, constrained only by your imagination.

• KiCad Projects
• PDF Schematics
• JLCPCB Production Files (Gerber, BOM, CPL)
• StackFlex Arduino Library [tbd]

1. ESP32-S3 Mini 1 Module: Powerful and energy-efficient microcontroller featuring dual-core processing, integrated WiFi and Bluetooth LE connectivity, AI acceleration, and extensive peripheral support.

2. 3.7 V LiPo: Power StackFlex using a LiPo battery with state-of-charge (SOC) monitoring.

3. USB C Connector: State of the art connector to programm and power the microcontroller and its peripherals.

4. LiPo Charging: LiPo charges via USB if it is connected.

5. Power Monitoring: Monitor the power consumption and current of stacked Feature PCBs.

6. GPIO: Rotationally symmetrical GPIOs for enhanced flexibility.

7. LEDs: Two status LEDs (red, green)

=> Detailed documentation here.

Feature PCBs enhance the fucntionality of the StackFlex system. Here is a list of already developed Feature PCBs:

• Air Quality Feature PCB
  • Gas Sensor (TVOC, eCO2)
  • Temperature
  • Ambient Light Sensor
  • WS2812B Status LEDs
• more to come..

Develop and build your own Feature PCB with the provided KiCad Template Project.

=> Detailed documentation here.