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.
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
A momentary or non-latching switch which causes a temporary change in the state of an electrical circuit only while the switch is physically actuated. SWITCH TACTILE SPST-NO 0.05A 24V
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.