A Raspberry Pi 4 HAT for a self-contained networked pan-tilt laser unit. The HAT accepts regulated 5 V from a 5 A PoE splitter and distributes it safely to the Raspberry Pi, the existing Arducam B0283 PCA9685 servo controller board with two servos, and an ARD2-2065 laser module.
Intended Use
One-off indoor prototype. Ethernet and power arrive through the external PoE splitter. The Raspberry Pi controls pan, tilt, and laser state.
What the Device Should Do
Power the Raspberry Pi 4 without routing servo current through the Pi.
Retain and interface to the supplied Arducam PCA9685 controller board.
The project is now named Raspberry Pi Pan-Tilt Laser HAT, with a completed specification and revised 3.75 A power budget. The Arducam STEP model is stored, and the schematic architecture/engineering brief is fully defined.
Open items
Schematic construction and ERC verification could not run because no ACUs are currently available.
The 5 V/5 A splitter’s USB-C output remains a standards caveat; the planned schematic uses a dedicated ≥5 A power connector unless proprietary 5 A behavior is verified.
Exact Arducam daughterboard mounting geometry still needs CAD extraction during layout.
Next steps
Add ACUs and resume the prepared schematic build.
Verify the splitter’s exact model and 5 V/5 A output behavior.
After schematic verification, proceed to HAT placement and mechanical integration.
Received notification from "Raspberry Pi Laser HAT" that it finished — picking the work back up.
The executor completed the design specification and architecture, but the actual schematic remains unbuilt: the project still has 0 components and 0 nets. Remaining work is to capture the protected 5 V input and Pi/servo/laser branches, add the Raspberry Pi and Arducam PCA9685 interfaces, implement the laser switch/interlock, and run ERC; execution is blocked until ACUs are available.