ESP32 Indoor Air Quality Module
1:22
Planning PCB Development.
Your goal is to implement the exact 55×45 mm, 2‑layer ESP32‑C5 IAQ monitor with USB‑C, OLED, PMS7003, STCC4+SHT41, and a common‑anode RGB LED, then export all files.
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Plan to execute:
- Add all parts/passives and programming pads; lock USB D−=GPIO13, D+=GPIO14; avoid strap pins; IO15 unused.
- Wire schematic exactly per your netlist (I2C pulls, STCC4↔SHT41 bus, PMS UART on GPIO23/24, RGB LED resistors to GPIO6/9/10, EN RC, CC 5.1k, ESD).
- PCB layout: 55×45 mm, strict antenna keep‑out both layers; power block by USB‑C; sensors at edge and ≥10–15 mm from LDO/MCU; solid bottom GND; labeled test pads.
- Reviews & exports: ERC/DRC, availability; verify strap rules; export schematic PDF, BOM CSV, Gerbers+drill, P&P; compile review notes.
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Note: Based on Flux knowledge base guidance, I will include programming pads (U0TXD GPIO11, U0RXD GPIO12, EN, GPIO28, 3V3, GND) for reliable post‑assembly flashing.
Click Start on the plan bar to begin execution.
Plan
- Design a USB‑powered, 55×45 mm, 2‑layer ESP32‑C5 IAQ monitor board integrating STCC4+SHT41, PMS7003 (UART), SSD1306 OLED (I²C), a common‑anode RGB LED, and complete power/protection circuitry (AP2112K‑3.3 LDO, polyfuse, USBLC6‑2SC6 ESD). Adhere to USB pin locks (USB D− as GPIO13, D+ as GPIO14), avoid strap pins, leave IO15 unused, and isolate the SHT41 to the STCC4 bus. Include labeled test points and programming pads for U0TXD (GPIO11), U0RXD (GPIO12), EN, GPIO28, 3V3, and GND, ensuring a production-grade design suitable for IAQ monitoring.
#Implementation plan
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Component Selection and Schematic Setup
- Select and add the ESP32‑C5‑WROOM‑1‑N8R4, ensuring USB pin assignments are locked: USB D− to GPIO13 and USB D+ to GPIO14.
- Add the STCC4 (STCC4-D-R3) and configure it as the exclusive compensation bus for the SHT41 sensor (SHT41‑AD1B‑R3).
- Add the PMS7003 sensor, wiring its TXD to GPIO23, RXD to GPIO24, and SET to GPIO8 via a dedicated 1×6 header.
- Add the SSD1306 OLED display using a 1×4 header; route I²C on GPIO4 and GPIO5 with 4.7kΩ pull-ups to the 3V3 rail.
- Include the ASMB‑MTB1‑0B3A2 common‑anode RGB LED. Connect its anode to 3V3 and add 680Ω resistor for red on GPIO6, and 220Ω resistors for green and blue on GPIO9 and GPIO10 respectively.
- Incorporate power supply components: USB‑C connector with CC configuration (5.1kΩ resistor to GND), polyfuse, AP2112K‑3.3 LDO, and USBLC6‑2SC6 for USB ESD protection.
- Add labeled test points and programming pads for U0TXD (GPIO11), U0RXD (GPIO12), EN, GPIO28, 3V3, and GND.
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Schematic Wiring and Net Connections
- Connect the USB‑C connector: wire CC with a 5.1kΩ resistor to GND, route D− through ESD to GPIO13 and D+ through ESD to GPIO14.
- Wire the power path: route USB‑C VBUS through the polyfuse to the input of the AP2112K‑3.3 LDO, providing the 3V3 rail.
- Connect I²C signals from ESP32‑C5 GPIO4/5 to both the OLED and the SHT41 (via the STCC4 bus), using 4.7kΩ pull-ups.
- Wire the PMS7003 sensor to the UART pins as specified and ensure proper connection for the SET line.
- Route connections for the RGB LED with designated resistors from the respective GPIO pins to the LED cathodes.
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PCB Layout and Mechanical Considerations
- Set the board dimensions to 55×45 mm and ensure a strict two-layer design.
- Define and reserve an antenna keep‑out area for the ESP32‑C5 across both layers.
- Place the USB‑C connector and power block near each other for minimal power routing length.
- Position sensors (SHT41 and PMS7003) near the board edge (at least 10–15 mm away from other power components), and group labeling for test points and programming pads along the board perimeter.
- Ensure decoupling capacitors are placed close to the MCU’s power pins for optimal performance.
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Design Review and Output Generation
- Run ERC/DRC to confirm net connections, strap pin compliance, and proper avoidance of IO15 usage and unwanted strap pins.
- Verify that all components (including sensor and I/O headers) are correctly oriented and that test points and programming pads are clearly labeled.
- Export final deliverables: schematic PDF, BOM with MPNs, Gerbers, drill files, and pick & place file.
- Compile design review notes focusing on power routing, antenna keep‑out, ESD protection, and proper test pad placements.
#Success criteria
- All specified components are correctly selected, added, and interconnected per requirements.
- USB‑C connections enforce the pin locks (GPIO13 for D−, GPIO14 for D+), with avoided strap pins and unused IO15.
- Complete generation of design outputs: schematic PDF, BOM CSV, Gerber files, drill, and pick & place files with appropriate labels and test points.
- PCB layout adheres to a 55×45 mm size, with correct component placement, defined antenna keep‑out, and proper power management.
Start with symbols and footprints
Lock in the USB-C and protection
Clarify PMS7003 header pin order
Help with EN/BOOT circuitry details
Ask about routing constraints
118 days
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