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    XIAO Expansion Board with XIAO ESP32C3

    An XIAO ESP32C3 microcontroller and an XIAO extension board manufactured by Seeed Studio comprised the heart of this project.

    It comes with rich peripherals that include an OLED, RTC, SD Card Sot, passive buzzer, reset/user button, 5V servo connector, and Grove connector for pairing multiple Grove devices with XIAO.

    We can power the entire setup using any Li-ion or LiPo cell thanks to its integrated Li-ion charging circuit.

    If you would like to get one for yourself, here is the link to its page.


    The RTC, the battery input section, and the OLED display are the three components we employ total on the expansion board.

    The OLED and RTC are connected to the XIAO's i2c Pins, allowing us to control them directly without requiring additional connections.

    the Adafruit's SSD1306 library can be use with the OLED Screen but you can also use the u8g2 library.

    You can check out Seeed Studio's brief product introduction for the expansion board, which includes a ton of information, by clicking the link below.


    Visit Seeed Studio to get a wide range of services, including 3D printing, PCB/PCBA, and microcontroller/module services.

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    Initially, we had the idea of reviving an outdated CASIO vintage watch frame that I had with the XIAO expansion board.

    The expansion board contains the display, microcontroller, RTC and even the battery, so we prepared a rectangular holder that will be fixed to the existing watch frame and will house the expansion board and battery.

    Two sections of the expansion board holder were modeled. The battery was positioned between the expansion board and the top body, and the top portion essentially served as a holder that the expansion board was screwed onto.

    On the bottom side, there's another part that is added from the internal side of the watch frame; this part is screwed on the bottom side of the top part through two M2 screws and holds the watch frame.

    After finalizing the model, we 3D printed both parts with white PLA through a 0.4-mm nozzle and 20% infill.

  • 3
    Assembly Process

    The holder part is added from the bottom side of the frame after the top part has been assembled onto the watch frame. Two M2 screws are used to secure everything in place