AI Badge Avatar PCB completion — ESP32-S3, LCD, mic, LiPo

We have an AI-assisted KiCad A1 draft for a wearable character badge. It has schematic sheets and provisional placement, but no copper routing; several circuits and connector choices are unfinished. The product requirements have expanded to voice AI from the cloud over Wi-Fi, while character images/animations stay on the device. The A1 draft has no microphone, so that is a new circuit to design. This project is for hardware/PCB engineering; application firmware and the cloud AI service are separate work. Remote engineering is fine. We will share the review files privately.

Hardware and user experience
- ESP32-S3-WROOM-1-N16R8 with built-in 2.4 GHz Wi-Fi. Check antenna placement/keep-out; do not add a second Wi-Fi modem.
- 4.3-inch 800 x 480 parallel RGB LCD candidate SZCLX043J-G-1000-IPS-16-X, 3.3 V logic and about 24 V / 40 mA LED backlight. Recheck the draft TPS61165 backlight circuit for this panel.
- 3.7 V / 2,000 mAh LiPo, USB-C charging/programming, 4 GB permanently soldered storage for local characters and animations. Choose/verify the exact storage part and interface.
- Add an onboard microphone suitable for push-to-talk voice input to the ESP32-S3. Keep the existing MAX98357A speaker amplifier provision and provide a verified connector/output for a small speaker. Check speaker rating, volume, microphone placement and electrical/acoustic noise.
- No touch UI is assumed. Propose a usable physical control scheme: ideally Talk/Select, Previous and Next user buttons, with a long press to open an on-screen settings menu for avatar selection, volume and Wi-Fi status/setup. If two user buttons are preferable, explain the short/long-press navigation before fixing the PCB. Keep power and recovery controls accessible. Review GPIO allocation and add an expander if needed.
- Draft four-layer PCB is about 60 x 111 mm with a 52 x 40 mm battery opening. Verify buttons, speaker/mic ports, display flex, connectors, RF clearance and essential case fit.

Engineering scope
1. Independently review/correct the draft schematic. Complete microphone and controls, storage/GPIO allocation, battery cutoff/protection, charging while the main switch is off, USB source-current/suspend behavior, power budget and connector choices.
2. Qualify or revise the LCD/backlight interface. Identify missing panel timing, FPC and battery information to confirm with the supplier or owner.
3. Select components with JLCPCB/LCSC availability in mind before final layout; recheck before any order. Provide part numbers and approved alternatives; flag items that require separate sourcing or hand assembly. No purchases without our approval.
4. Finish PCB placement/routing and run ERC, DRC and manufacturing checks. Resolve issues or document remaining limitations clearly.

Deliverables: editable KiCad schematic/PCB, BOM with manufacturer and JLCPCB/LCSC numbers, Gerber/drill and placement files, assembly notes, power and pin-map notes, and a bring-up plan. Provide remote help with the first assembled prototype and one correction pass if it reveals a PCB design error.

Target engineering budget: $350 USD fixed, with the added microphone/control scope to be confirmed before award. Target schedule: 10–14 days for the design package after scope agreement. Fabrication, parts and shipping need separate approval. The first prototype must be physically tested before production release.