Completed the requested start of PCB layout by resizing the board to a compact 80 mm x 70 mm 4-layer outline and placing the major components.
Preserved mechanical access by keeping J1 on the USB edge, U6 on the field-wiring edge, J2 accessible for service/programming, and IC1 at the top edge with outward antenna orientation.
Grouped the power and interface circuitry logically: U3, F1, D1, and D3 near J1; U4, D5, R4, and R6 near U6; IC2 with the 3.3 V stage; and IC3 with the 12 V boost stage.
Verified the placement state is clean with no component overlap or out-of-bounds placement issues.
Success criteria review
✅ All major components are placed on the PCB layout with a logical and accessible arrangement.
✅ The board outline is adjusted to a tight but workable configuration that preserves routing corridors and mechanical edge access.
✅ Placement follows the project constraints for USB, RS-485, power grouping, and ESP32 antenna edge placement.
Next steps
This placement stage is complete. The remaining work is the next phase of layout: routing and any minor manual nudging after traces begin.
Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
General Purpose Thick Film Standard Power
and High-Power Chip Resistor
47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film
Features:
- RMCF – standard power ratings
- RMCP – high power ratings
- Nickel barrier terminations standard
- Power derating from 100% at 70ºC to zero at +155ºC
- RoHS compliant, REACH compliant, and halogen free
- AEC-Q200 compliant
ESP32-based controller for an external RS-485 ultrasonic water flow sensor, powered from USB-C with onboard 3.3 V logic supply and boosted 12 V sensor supply.