The Mini Optical Filter Wheel is a low-cost, compact device for switching between eight 8x8mm optical filters. It is designed around the use of small square filters, which are significantly more affordable than traditional round threaded optics, making it a practical choice for low-budget spectral imaging and other optical experiments. This makes optical filter based Spectral Imaging significantly more affordable and accessible to makes, students, and hobbyist interested in exploring with this technology.

At the core of the system is a custom-designed controller board based on an STM32 microcontroller, paired with a miniature 8 mm stepper motor and a magnetic encoder for precise, reliable positioning of the filter wheel. The board supports both I2C and UART interfaces for easy integration with platforms like Arduino or Raspberry Pi. Optional trigger in/out lines enable for synchronized operation with camera shutters or flashes, such as with the Multispectral Illumination project.

Features:

• Filter Format: Supports standard 8x8mm square optical filters
• Compact Design: Small footprint fits tight optical setups
• Materials: 3D-printable parts, affordable components
• Accurate Positioning: Magnetic encoder with 14-bit resolution
• Open Hardware: Fully documented design with printable and source files
• Flexible Control: I2C and UART interfaces for microcontroller integration

Full project information and assembly guide can be found here: Mini Optical Filter Wheel