PCB Design Validation – ESP32 Solar Powered IoT Controller

Description:
We are developing a solar-powered ESP32-based IoT controller for agriculture field deployment (valve control and sensor monitoring). Before sending the PCB for manufacturing, we are looking for an experienced hardware/PCB engineer to independently review and validate the complete design to ensure it will work correctly and avoid fabrication risks.
This task is strictly for design validation and technical review, not for redesign.
System Overview:
The board includes the following major components:
ESP32 microcontroller
Solar powered system (12V nominal solar panel input)
MP1584 buck converter (solar to 5V)
IP5306 Li-ion charger / power management
18650 Li-ion battery
9V boost converter for latching solenoid valves
DRV8833 motor driver
TPS3435 watchdog timer
CH340C USB-UART interface
RS485 sensor interface
Multiple sensor inputs
The device will be deployed outdoors in agricultural environments, so reliability and power stability are critical.
Scope of Work:
The freelancer will review the following files:
Schematic
Netlist
PCB layout
Bill of Materials (BOM)
Validation should include:
Electrical Design Review
Verify IC pin connections with datasheets
Confirm correct voltage levels and power domains
Validate ESP32 boot/reset circuitry
Verify USB-UART logic level compatibility
Review watchdog configuration
Power System Review
Solar input compatibility (12V nominal panel)
Buck converter configuration
Battery charging path
Battery protection and load behavior
Boost converter sizing for valve loads
Protection & Reliability
Reverse polarity protection
Surge protection for solar input
Input filtering and decoupling
ESD considerations
Power stability under load
PCB Layout Review
Power trace sizing
Ground plane integrity
Switching regulator layout
Thermal considerations
Noise isolation around ESP32
Manufacturing Readiness
DRC/DFM review
Identification of potential failure points
Recommendations before fabrication
Deliverables:
Detailed design review report
List of issues categorized as critical, recommended, or optional
Suggested corrections if required
Final recommendation on whether the design is safe for PCB fabrication
Required Experience:
Applicants should have experience with:
ESP32 hardware design
Solar and battery powered embedded systems
Switching regulators (buck/boost)
Embedded electronics design and PCB validation
Experience with tools such as KiCad, Altium, or EasyEDA is preferred.
Files Provided:
Selected freelancer will receive schematic, netlist, PCB layout files, and BOM for review.

The goal is to ensure the PCB design is technically correct and ready for manufacturing to avoid costly revisions.