Components

The entire block is made up of readily available materials.

Electronics

• SeeedStudio XIAO ESP32S3 (Plus) & WiFi antenna
• 2 Microswitches (12.8 x 6.5 x 5.8 mm)
• 128x64 SSD1306 OLED with I2C connection
• Adafruit PCF8523 & CR1220 12mm diameter coin cell battery

Components required for assembly:

• Protoboard
• Standoffs
  • 7x1 (twice for the microcontroller)
  • 4x1 (for the display)
  • 5x1 (for the clock)
• Wire

Optionally, you can also wire up a battery for the ESP itself, to use Precious Block on the go (recommended)

• Lithium Battery (3.7V; should not be larger than 3x3x0.5cm)
• 2x 220kOhm Resistors (if you want to be able to read the voltage)

Difference between different Seeed XIAO ESP32 S3 chips

As the name indicates, the Plus chip is slightly more advanced. The differences relevant to this project are listed below. (Details taken from the Seeed Wiki)

The larger flash size on the Plus model is certainly helpful for development work, as debug builds tend to be larger than release versions.

Both chips allow connecting to a rechargeable 3.7V lithium battery.
The current battery state is indicated by a red light, on the chip.

• No battery: Red light turns on when connected and turns off after 30 seconds
• battery fully charged: red light turns of
• battery charging: the red light is blinking

Case

The case is designed using FreeCAD. The project file contains multiple Spreadsheets which are used to make important variables easily adjustable.

• 3D printed front, back & 2 arms
• 8 3x3x3 mm magnet cubes