Pilomar is a 3D printed Raspberry Pi based miniature observatory.

It can automatically locate thousands of night sky objects, it then tracks and photographs them.

You can process (stack) the images to produce higher quality cleaner images using free software.

This demonstrates some of the operation of larger observatories and can be expanded or modified for you own project.

The motorcontroller board controls the motion of the camera as it tracks an object across the sky using precise stepper motors.

It takes instructions from a connected Raspberry Pi, then follows the defined sky path automatically.

This supports a Raspberry Pi Pico 2 and TMC2209 stepper motor drivers.

It communicates with a separate Raspberry Pi model 4 or 5 computer.

The microcontroller board may be useful for other projects or telescope designs.

This is the V3.1.1 board design for the project, you need the latest (2026) version of the software from GitHub to communicate correctly with this new circuit. If you want to use the original Pimoroni Tiny2040 and DRV8825 components you should use an earlier circuit design.

The full project is on the Instructables website here.

This PCB design is for the unpopulated board, you need to add appropriate components yourself. The diagrams above show the component placement.

You will need to add :

• 1 x 40 pin Raspberry Pi GPIO header.
• 2 x 20 pin headers for Raspberry Pi PICO2.
• 4 x 8 pin headers for TMC2209 drivers.
• 2 x 2 pin headers for TMC2209 drivers (NOTE: 2 extra pins along top edge of driver board).
• 2 x TMC2209 driver boards (recommend BigTreeTech V1.3 or equivalent).
• 1 x Raspberry Pi PICO2 microcontroller (NOTE: PICO1 does not work).
• 1 x 1N5817 Schottky diode.
• 2 x 4.7K resistors.
• 2 x 1.0K resistors.
• 1 x 10K resistor.
• 2 x 4 point terminal block.
• 1 x 2 point terminal block.
• 3 x 100uF Capacitors.