RELEASE HOLD. @power-budget~c0 is now the authoritative quantitative motor assessment: nominal5V/15×1.47A=22.05A/110.25W published stall reference, not continuous demand or guaranteed maximum. Use30A/150W as PROVISIONAL capability comparison only;25A option and conditional15A current-limited alternative are not final hardware approvals. D24V150F5 is rejected for unrestricted25–30A service; input-dependent TDK i7A12060A008V candidate needs exact variant/support/thermal/fit/protection qualification. No power hardware implemented. Battery product/BMS/loaded endpoints, actual harness/contact assemblies and lengths, ambient/airflow/CAD, torque/duty and acceptance of limiting remain blockers. Budget contains measurable commissioning gates; no layout/fabrication release.

Microcat Rev 8 torso controller/interface PCB. Status: Draft for engineering review, NOT fabrication approved. Authoritative owner brief: Rev 8 full source. All selected models and provisional numeric allowances below are owner requirements, not independently verified datasheet facts.

Prototype robot using the official NVIDIA Jetson Orin Nano 8GB Developer Kit and15 owner-selected XL330-M288-T Dynamixel TTL motors. Produce exactly ONE custom torso PCB, plus bought modules including ROBOTIS U2D2,labelled harnesses and printed mounts. No Raspberry Pi or custom head/IMU adapter PCB.

Distribute protected battery power, safely disable motors, acquire timestamped torso motion data independently of Linux timing, communicate motor commands, provide audio playback and optional backup capture, and connect the purchased head controller.

Target features:3S LiPo distribution,motor power disable,pack/cell undervoltage handling and graceful shutdown;purchased U2D2 half-duplex TTL communications;integrated LSM6DSV16X with dedicated MCU;MAX98357A speaker output;primary owned CM-103 USB microphone;optional torso I2S MEMS backup. High-current power/protection/disable remains absent,not preserved working hardware. Head expressions run locally on bought Waveshare ESP32-S3-DEV-KIT-N16R8 SKU28409.

Battery and Jetson in body; one combined torso PCB, external bought servo converter allowed, head devboard plus ONE display and local ToF carrier. Torso -> moving-neck harness -> head devboard -> short passive screen cable. Jetson-in-body is provisional, not an approved enclosure. Historical split-board outlines and bare WROOM envelope are superseded. Actual Fusion CAD, purchased hardware revisions, cooling and swept-neck checks are not supplied. Do not fabricate an outline or move high-current hardware into the head to fit an old shell.

Required future power tree:3S battery -> input protection/distribution -> independent Jetson DC-jack branch,servo-converter branch,auxiliary branch;common reference ground with segregated high-current returns. Actual motor communication:Jetson USB -> bought U2D2 -> external passive GND/DATA harness -> motors;separate protected5V injection/return is required but unimplemented. U2D2-side pin2 conductor is omitted/insulated. Jetson J12 -> torso control/audio and protected face-host I2C. Jetson USB -> owned CM-103;CSI -> IMX219 directly. Dedicated torso MCU -> local LSM6DSV16X,with independent host UART,NOT a DXL slave or motor master. Purchased head ESP32 -> local SPI LCD/OLED and optional local ToF bridge.

Verify exact Jetson carrier revision,J12 and J20/J21 nomenclature. Candidate J12 I2C pins3/5 remain conditional. Proposed custom PH2.0 face harness:1 AUX_5V_FACE,2 GND,3 FACE_SDA,4 FACE_SCL;NOT Qwiic. Start host I2C at100kHz,proposed address0x42 subject to review,power-off isolation required. U2D2 now owns the motor path,not a parallel service master. PCB J6 is custom PH diagnostic1 GND/2 NC/3 DATA,not an EH motor mate or power feed;TP5 is passive DATA. J4 pins5/6 are NC. Define actual keyed mating/wire-entry drawings;never infer cavities from colors. See U2D2 Migration for external motor pinout and protected-power boundary.

Single3S LiPo;no charging circuit specified. Motor model is now XL330-M288-T;pack capacity/discharge capability,cell-monitor connector,load duty cycle and runtime remain unknown. Off-board balance charging assumed and must be confirmed. Preserve auxiliary operation for computer shutdown;pack cutoff and motor disable must not depend solely on Linux or U2D2 commands.

Required3S input splits after protection into computer,servo and auxiliary branches;not implemented. Servo target5.0V;current-envelope details and vendor operating conditions are recorded in U2D2 Migration and Power Budget,NOT normal consumption or converter approval. Remove obsolete onboard motor-logic5V load;U2D2 draws from USB,not motor power. Face allowance5V/1A remains provisional. Auxiliary budget includes MCU,audio,sensors and face startup;nominal2A is not automatically adequate. Fuse/FET/connector/copper values and runtime remain blocked by measured loads and battery data.

Exactly one custom PCB design/manufacturing set when released; preferred LCSC availability and JLCPCB Basic parts where suitable. Start from a four-layer proposal, continuous ground reference; final copper, board outline, thermal and EMI suitability require review. Preserve R/C/U designators plus visible exact MPN/model. Footprint/package verification mandatory. No Gerbers until release gates close.

MCU debug/programming,watchdog,safe boot,shutdown handshake and deterministic IMU sampling with documented timestamp/map. Remove USART1 motor-master and PB0 OE logic;retain USART2 IMU telemetry. Jetson DYNAMIXEL SDK has sole U2D2 ownership with verified persistent USB identity. Face commands include version/length/CRC/sequence/status,bounded queues,timeout/recovery and local neutral face. LCD_240 default and OLED_242 saved profile,power-off swaps only. USB/external-devboard5V isolation and motor-off DATA leakage require validation. Jetson pinmux/device-tree/ALSA and firmware remain unbuilt/unvalidated.

No validated combined torso envelope exists. Confirm module revisions, connectors, cooling/fan clearance, power converter location, mounting, strain relief, microphone acoustics, camera/ToF openings and both removable screen inserts. Four-layer stackup is a proposal only; no invented board size or HAT outline.

One custom torso PCB plus bought head devboard. External high-current servo converter allowed rather than an unreviewed integrated converter. Retain primary USB capture and optional short torso I2S capture; no raw microphone I2S across neck. LCD and OLED interchangeable only by passive cable and insert, one at a time.

Unverified:exact carrier/JetPack revisions,motor load measurements,LiPo capacity/rating,acoustic performance,U2D2/head mechanical revisions,harness capacitance/length,converter fit,regeneration and motor-off backfeeding. Actual bench tests require hardware. Missing CAD prevents fit approval only,not safe independent capture. Native72-part capture has44 populated electrical nets;ERC clear but206 airwires,50 bounds warnings,one J1/J3 overlap and C7/C8/C13 MPN errors remain. Current160x100mm outline/four-layer stackup and all surviving baseline poses are preserved,NOT approved fit. No fabrication.

2026-10-19:Rev8 source adopted;older split-board concepts excluded. U2D2 revision:backup saved;16 exclusive MCU motor-host parts removed;independent IMU UART/audio/face preserved;passive diagnostics and separate external power boundary documented;baseline outline/poses restored. See U2D2 Migration for exact delta,wiring and verification. Schematic drafting,real placement/routing,power implementation and fabrication remain separate gates.