HDMI CEC & IR Controller Board Design

About the project

Project Brief: ESP32-P4 + ESP32-C6 HDMI CEC & IR Controller Board 1. Project Overview Seeking an experienced PCB designer to create a custom, compact controller board designed to manage media devices via HDMI CEC and external Infrared (IR). The architecture relies on a dual-MCU setup: an ESP32-P4 acting as the primary application processor (handling HDMI protocols and IO) and an ESP32-C6 serving as the wireless (Wi-Fi/BLE) network co-processor. 2. Core Processing & Architecture * Main Application Processor: ESP32-P4. * Network Co-processor: ESP32-C6. * Interconnect: Implement a high-speed communication bus (e.g., SDIO or SPI) between the P4 and C6 for network bridging. * Debugging (Optional but recommended): Expose standard JTAG test points or a micro-header for both MCUs to facilitate low-level dual-chip firmware debugging. 3. HDMI Interface (CEC 2.0 & E-DDC Compliant) * Connector: 1x HDMI Female connector. * CEC Physical Layer (Pin 13): * Route to an ESP32-P4 GPIO capable of utilizing the RMT (Remote Control) peripheral. * Include a 27kΩ (±5%) pull-up resistor to the 3.3V rail. * Include a blocking diode (e.g., Schottky BAT54) in series with the CEC line, oriented per the HDMI specification to prevent the unpowered board from pulling down the host system's CEC bus. * E-DDC & I2C Logic Level Shifting (Crucial): * HDMI DDC lines (SDA on Pin 16, SCL on Pin 15) operate at 5V. Include a bidirectional I2C logic level converter (e.g., PCA9306 or BSS138 MOSFETs) to safely step these down to the 3.3V logic of the ESP32-P4 hardware I2C pins. * Hot Plug Detect (HPD on Pin 19) operates at 5V. Step this down to a 3.3V GPIO input via a level shifter or voltage divider. * Properly route the HDMI 5V Power (Pin 18) to supply the high side of the level shifters. * Protection: Include robust ESD protection/TVS diode arrays on all exposed HDMI lines. 4. External Infrared (IR) Interfaces Include two separate 3.5mm audio-style jacks for external IR communication, routed to RMT-capable GPIOs on the ESP32-P4. * IR Transmitter (Blaster) Jack: * Connector: 3.5mm TS (Mono) or TRS jack. * Driver Circuit: The ESP32 cannot directly drive an external IR blaster. Include a driving transistor circuit (e.g., NPN like 2N2222 or an N-channel MOSFET) to switch the IR LED current. * Include an appropriate current-limiting resistor scaled for a standard high-power external IR emitter. * IR Receiver Jack: * Connector: 3.5mm TRS (Stereo) jack (Requires 3.3V Power, Ground, and Data Signal). * Signal Integrity: Include a 10kΩ pull-up resistor on the data line. * Filtering: Include a 0.1µF decoupling capacitor close to the jack's power pins to filter cable noise. 5. Power & Programming * Connector: Exactly 1x USB Type-C connector. * Placement: Must be mounted on the back of the board, located on the short edge of the PCB. * Functionality: Utilized for both 5V power delivery and MCU flashing. Include ESD protection on the USB D+/D- lines. * USB-to-UART: Include an onboard bridge (e.g., CP2102N or CH340). * Auto-Download: Implement standard auto-reset circuitry (dual-transistor circuit connected to Boot and EN/Reset pins) for seamless flashing. * Power Regulation: High-efficiency 3.3V LDO voltage regulator(s) with sufficient thermal and current overhead to handle peak Wi-Fi transmission spikes from the C6 alongside the P4's workload. 6. User Interface (On-board) * Buttons: 2x Tactile Push Buttons (1x Reset/EN, 1x Boot/IO0). * Indicators: 2x Controllable Status LEDs (1x Blue, 1x Green), each routed to independent GPIOs with appropriate current-limiting resistors. 7. Layout Constraints & Deliverables * Footprint: Keep the board footprint as compact as reasonably possible while ensuring proper thermal dissipation. * RF Layout: Strictly adhere to RF layout guidelines for the ESP32-C6 antenna (proper keep-out zones, trace impedance matching). * Required Deliverables: * Complete Schematics (Original EDA format like KiCad/Altium, plus PDF). * PCB Layout files (Gerbers, Drill files, Pick & Place/Centroid files). * A comprehensive BOM (Bill of Materials) optimized for standard assembly services (e.g., JLCPCB/LCSC) with manufacturer part numbers. * 3D CAD step file (.step) of the fully assembled board for enclosure design.

Skills required