Domain: Engineering — Electrical Engineering
Target concept: DAC feeding RC filter then lighting LED with gradual rise/fall

Video generation prompt: On the workbench, a microcontroller's DAC drives an LED through an RC filter, and the program continuously updates the DAC value.

Evaluation guide:
(i) Target concept: Analog signal reconstruction via RC low-pass filtering of DAC output, enabling perceptible smooth LED dimming.
Minimum mechanism: DAC must output time-varying digital values → RC network must integrate those values into a continuous voltage waveform → LED must respond to that voltage with proportional luminance → human vision must resolve gradual change rather than abrupt jumps.
(ii)Storyline: Frame 0–1: Static wide shot showing full setup (microcontroller, DAC pin, R, C, LED, wiring, workbench). Frame 2–3: Close-up on DAC pin showing activity (e.g., blinking indicator or label update) → Frame 4–5: RC stage in view: resistor and capacitor sit inline between the DAC pin and the LED, with no visible change in either component's appearance (no glow, no color shift); the capacitor's charging is inferred only from the LED's subsequent smooth brightness ramp, not shown directly → Frame 6–8: LED begins luminance ramp (uniform gradient, no jump) → Frame 9–10: LED completes ramp up, holds, then ramps down identically; entire sequence occurs from fixed frontal viewpoint with stable lighting and no cuts.

Manual:
Experimental Procedure
1. Place microcontroller board on workbench.
2. Connect DAC output pin to one lead of resistor.
3. Connect other resistor lead to one capacitor lead.
4. Connect other capacitor lead to LED anode.
5. Connect LED cathode to ground.
Observation of Experimental Phenomena
LED brightness increases gradually from off to maximum, then decreases gradually back to off — smoothly and repeatedly, with no flicker or steps.
Summary of Experimental Principles
DAC generates analog voltage; RC filter smooths rapid digital updates into continuous voltage; smoothed voltage drives LED current, producing perceptible gradual luminance change.

Prompt Grounding rubric:
level_1: No microcontroller, no DAC output interface visible, no RC filter components (resistor and capacitor) present, no LED visible, no workbench setting, or all objects are incorrectly labeled/missing.
level_2: At least one correct object is present (e.g., microcontroller board OR LED OR resistor OR capacitor), but none are connected in a plausible DAC→RC→LED signal chain; no visible wiring between DAC output pin and RC input; LED not positioned downstream of RC; workbench context absent or inconsistent.
level_3: Microcontroller board, DAC output pin (labeled or clearly identifiable), resistor, capacitor, and LED are all present and placed on the same workbench; at least one wire connects DAC pin to resistor; resistor connects to capacitor; capacitor connects to LED anode; LED cathode connects to ground; all connections are physically plausible and visible, though some wiring may be ambiguous or occluded.
level_4: All objects from score 3 are present and correctly connected in sequence: DAC pin → resistor → capacitor → LED anode → LED cathode → ground; all connections are unambiguously visible (no occlusion, no floating wires); microcontroller is powered (e.g., USB cable or power LED lit); LED is mounted upright on breadboard or PCB with correct polarity visibly indicated (e.g., flat edge, longer lead, or marking).
level_5: All elements from score 4 are present and additionally: (a) the DAC output pin is visually distinguishable from the microcontroller's other pins as the single point where a wire departs toward the resistor, even without legible printed text such as "DAC" or "A0"; (b) the resistor (small cylindrical body with colored bands) and the capacitor (disc-shaped or cylindrical body with a visibly different form factor from the resistor) are clearly distinguishable from each other by shape and size alone, without requiring readable value markings such as "10k" or "100n"; (c) the LED shows visible polarity confirmation (flat cathode side plus a distinct, differently-shaped anode lead) and emits light only after the RC stage; (d) the entire setup occupies a single fixed workbench scene throughout, with at most one brief close-up insert on the DAC pin to show its activity indicator (per the storyline) and no other cutaways or viewpoint changes.

Scientific and Causal Correctness rubric:
level_1: LED remains permanently off or permanently on; no intensity change observed; or LED brightness changes without any visible DAC update or RC filtering effect (e.g., instant step-change, flicker, or random pulsing); no gradual rise/fall behavior apparent.
level_2: LED turns on and off, but brightness transitions are discontinuous (e.g., abrupt on/off, binary toggling, or jerky jumps); no smooth monotonic increase or decrease in brightness visible; RC filter role is visually unrepresented (e.g., no delay between DAC update and LED response, or LED tracks DAC exactly without smoothing).
level_3: LED brightness changes continuously over time; at least one clear gradual rise (increasing luminance with no sudden jumps) AND one clear gradual fall (decreasing luminance with no sudden drops) are visible; timing of rise/fall aligns plausibly with program loop (i.e., smooth, repeating cycle), though exact symmetry or duration is not required.
level_4: All conditions from score 3 are met, AND LED brightness transition begins only after DAC output changes (visible temporal lag between DAC pin activity, e.g., blinking indicator or label update, and onset of LED luminance change); brightness curve shows no overshoot, ringing, or instability (e.g., no oscillation, no rebound, no stutter during ramp).
level_5: All conditions from score 4 are met, AND: (a) rise and fall phases are both strictly monotonic (no plateau, no reversal, no hesitation mid-transition); (b) the brightness ramps up and down at a visually even rate across each phase: no stretch of the ramp looks noticeably faster or slower than the rest, with no visible stair-stepping or banding (discrete jumps in brightness) and no visible plateau or stall partway through a rise or fall; (c) LED remains fully off before the first rise and fully off after the final fall: no residual glow or afterimage; (d) no competing light sources interfere with LED visibility.

Spatiotemporal Consistency rubric:
level_1: The LED, resistor, capacitor, or a connecting wire abruptly vanishes or appears between consecutive frames with no visible motion causing the change; the breadboard or microcontroller board jumps to a different position or orientation on the workbench without passing through intermediate positions; or a component (e.g., the capacitor) changes physical orientation instantaneously (e.g., snaps from upright to sideways) between frames.
level_2: Several discontinuities occur: more than one segment of the wire path connecting the DAC pin, resistor, capacitor, and LED disappears and later reappears with no visible movement; the LED or capacitor shifts to a different spot on the breadboard between frames with no motion shown; or the shadow cast by the LED and other components on the workbench switches to the opposite side more than once with no corresponding change in any visible light source.
level_3: The microcontroller board, resistor, capacitor, LED, and every wire segment connecting them stay in the same positions relative to one another on the breadboard for the entire clip; the wire path from the DAC pin through the resistor and capacitor to the LED stays continuously visible with no segment dropping out; the shadow cast by the LED and other components on the workbench surface stays on one side with steady darkness throughout, regardless of the LED's own brightness changes; the LED stays rigidly seated in its mount (no tilt, rotation, or bounce) as its brightness ramps up and down.
level_4: All conditions from score 3 are met, AND the sequence of visible events stays physically ordered and smooth: any DAC-pin activity indicator changes first, and only afterward does the LED's brightness begin to change, with no frame in which the LED's change jumps ahead of or lags behind this order; the wire outlines, breadboard holes, and component bodies show no jitter, ghosting, or misalignment from one frame to the next.
level_5: All conditions from score 4 are met, AND: (a) the camera framing of the workbench is fixed for the whole clip aside from at most one brief close-up insert on the DAC pin to show its activity indicator, with no pan, tilt, zoom, or drift otherwise; (b) the specular highlight on the resistor body and the capacitor casing shifts only in step with the LED's own changing brightness spilling onto them, never flickering independently or jumping to a different position; (c) no wire, breadboard hole, or component outline warps, stretches, or distorts in shape at any point in the sequence.