Work Completed
• Core architecture defined and documented (project description, system property, mermaid diagram).
• All major ICs placed: ESP32-WROOM-32D (U1), three SIM800L modules (U1–U3), RC522 RFID (U4), microSD socket (J1).
• Power subsystem components added: TPS62162QDSGRQ1 (U5), TPS562202 (U6), MAX16051ETI+ (U7), input jack (J2), TVS diode (D2), Schottky diodes (D1–D4), PTC fuse (F1), bulk/decoupling capacitors (C1–C7), inductors (L1,L2), pull-ups and enable resistors (R8,R9).
• Connectivity and interfaces complete in schematic: three Nano-SIM sockets (J3–J5), three U.FL connectors (J6–J8), USB-UART header (J9), test pads (TP1–TP4), status LEDs (LED1, LED2).
• Nets routed in schematic: UARTs to SIM modules, SPI to RFID and storage, power rails and enables, antenna lines, boot/reset pads, ground and VCC.
• Schematic reviewed and all component footprints verified (passive packages standardized, stackup set to Standard 4 Layer).
• BOM assigned real MPNs for generics (resistors, capacitors, inductors, diodes).
Remaining Tasks
- Measure PCB bounding box and define board outline with 10 mm margin
- Configure power/ground planes, ground fill rules, and layer assignments
- Add mechanical mounting holes near connectors
- Classify nets by type and set trace width rules
- Place all components on the PCB per RF and core-architecture constraints
- Route nets using Auto-Layout respecting RF keepouts and impedance controls
- Perform PCB DRC/ ERC review
- Conduct final manufacturability review of schematic and layout
Success Criteria Review
- ESP32, three SIM800L modules, MFRC522, and external storage fully integrated in schematic — ✅
- Robust power subsystem designed to handle GSM bursts with protection and sequencing — ✅ (schematic)
- All UART and SPI interfaces established with programming/debug header and status indicators — ✅ (schematic)
- PCB layout pending; full production-ready validation requires completing placement, routing, and reviews — ℹ️
Next Step
Per the agentic workflow, next is Prepare PCB Layout. I recommend measuring the current component bounding box in the PCB layout tool and defining the board outline (task 6.3) so we can lock in the board size before proceeding with planes, mounting holes, placement, and routing.