Embedded Engineer for Premium Kinetic Art Lamp

final technical specification and scope of work: premium kinetic art lamp 1. product vision and visual design. the goal of this project is to build one fully functional, highly polished physical prototype of a motorized, wall-mounted lamp designed explicitly for illuminating glass artwork. aesthetics: extremely minimalist, matte black gallery/reading lamp. it must not visually distract from the artwork itself. structure: a rectangular wall box, a slim l-shaped telescopic arm, and a compact cylindrical light head. enclosure: all mechanical components, motors, gears, pcbs, and batteries must be completely hidden inside the rectangular wall box. 2. kinematics and motion system. the lamp must perform a slow, ultra-smooth, and continuous automatic sweeping motion (similar to a slow-motion windshield wiper or high-end gallery display). silent operation: the system must be absolutely silent. the use of a stepper motor combined with a tmc2209 silent stepper driver is mandatory. motion profile: continuous, smooth motion with gentle acceleration and deceleration at the turning points. no jerky startup movements or harsh robotic stops. smart angle detection (as5600): an as5600 absolute magnetic encoder must be integrated. manual setup: when the lamp is off, the user can manually rotate the arm to a custom angle (e.g., 160°). symmetrical sweep logic: when turned on, the firmware reads the current angle and calculates a mirrored sweep range symmetrically around a 90° center axis. sweep example a: if manually set to 160°, the lamp sweeps back and forth between 160° and 20°. sweep example b: if manually set to 95°, the lamp performs a tight sweep between 95° and 85°. 3. mechanical arm and light head. telescopic arm: the arm must feature an adjustable telescopic mechanism to manually set the reach/distance from the wall. it must remain rigid and completely wobble-free during the motorized sweep. multi-directional ball joint (crucial): at the end of the telescopic arm, the cylindrical lamp head must be mounted on a robust multi-directional swivel or ball joint. joint functionality: the user must be able to manually tilt and rotate the light head downwards, sideways, and backwards toward the wall to precisely target the light beam onto specific glass cracks. upward adjustment is not required. 4. lighting and optics. led specifications: a highly focused, warm-white led spot (preferably high-cri). optics: a tir lens must be used to create a sharp, narrow beam specifically designed to highlight cracks in the glass art. thermal management: the compact cylindrical head must safely dissipate heat during continuous operation. 5. power system and battery integration. power source: internal battery compartment designed to hold two (2) standard 18650 li-ion cells. this ensures stable voltage for the stepper motor, extended runtime, and proper weight distribution. charging circuit: a pcb-integrated charging circuit with a usb-c port is required, allowing the batteries to be recharged directly inside the lamp. usb-c placement: the usb-c port must be located on the bottom of the wall box to keep cables hidden and maintain a clean aesthetic. shipping compliance: to avoid international customs issues, the prototype will be shipped from your facility without the 18650 batteries. i will source and install the batteries locally in germany. 6. smart power management and interface options. to prevent battery drain and offer maximum exhibition flexibility, the lamp requires a reliable sensor and switch setup. control interface flexibility: for the user interface, you can choose between implementing either a capacitive touch control on the lamp enclosure or a small remote control. please select the option that offers the best reliability and represents the most efficient development effort. hidden pir sensor: a compact, low-profile passive infrared (pir) motion sensor must be mounted on the bottom of the wall box. it must be hidden as much as possible (e.g., behind a tiny slit or flush-mounted dark plastic window). target detection range is 2-3 meters. firmware auto-timer: when motion is detected, the microcontroller wakes from deep sleep, turns on the led, and starts the sweep. when no motion is detected for a set duration, the system automatically shuts down the motor/led and returns to deep sleep. adjustable timer: the default inactivity timer should be set to 5 minutes, but the duration must be adjustable/configurable within the firmware code. 3-way manual override switch: a small, physical 3-way slide switch must be integrated on the bottom of the wall box, next to the usb-c port. switch position 1 (off): the entire system is completely powered down. switch position 2 (on - continuous): the led turns on and the arm sweeps continuously. this bypasses the pir sensor and timer entirely (intended for active gallery viewing). switch position 3 (auto - pir): the smart power-saving mode is active, relying on the pir sensor and the 5-minute timer logic. 7. simplified gravity mounting system. the mounting system must be tool-free, robust, and based on a double u-hook interlocking design. frame side: two small, inverted u metal brackets (approx. 3 cm wide) mounted on top of the wooden art frame. the open end faces downward and slightly forward. one on the left, one on the right, to prevent wobbling. lamp side: matching upright u brackets positioned on the bottom/back of the lamp enclosure, facing upward. gravity lock physics: the user slides the lamp horizontally (front to back) into the frame brackets. the forward-leaning weight of the telescopic arm creates a torque m = f * l that naturally wedges and self-locks the lamp tightly into place. it cannot tip forward or slide out during the sweeping motion. detachment: the user simply lifts the arm slightly to release the torque and pulls the lamp straight forward.