USB-C + Battery Powered ToF Sensor Device (ESP32-C3 + VL53L1X) – Hardware Debug & Fix

Budget: $30 - $250

Project Overview: I developed a compact round PCB (~3cm diameter) device called Metrifit Gym Pro. The device uses an ESP32-C3 microcontroller and a VL53L1X Time-of-Flight distance sensor.

The device is designed to work in two modes:

USB Mode (Wired): Powered via USB-C Sends distance data to a tablet via USB (serial/USB communication) Battery Mode (Wireless): Powered by a Li-ion battery Rechargeable via the same USB-C port Communicates via Bluetooth (ESP32-C3)

Current Problem: The PCB was manufactured, but it is not working correctly.

Main issue:

When connecting USB-C, the device is not powering up ESP32-C3 is not being energized No USB detection / no communication

What I Need: I need an experienced electronics engineer to:

Analyze the schematic and PCB (KiCad files) Identify why: USB-C is not providing power properly ESP32-C3 is not turning on Fix all design issues related to: USB-C power input (CC lines, VBUS, etc.) Power path (USB vs battery switching) Voltage regulation (3.3V rail stability) Ensure: Proper USB operation (power + data if applicable) Proper battery charging (TP4056) Safe and correct power switching (USB / battery) Suggest improvements for: Reliability Protection (ESD, stability, filtering) Deliver: Updated schematic (KiCad) Updated PCB layout Notes explaining what was wrong and what was fixed

Important Technical Details:

USB-C with CC1/CC2 resistors (5.1k pulldown) LDO regulator (TLV70233) Li-ion charging IC (TP4056) Schottky diode for power path VL53L1X sensor (I2C) ESP32-C3 with USB D+/D- connection

Known Suspicions (but need confirmation):

Possible issue in USB-C power negotiation Power path conflict between battery and USB Voltage drop due to diode affecting LDO input Potential layout or routing issue

Files: Full project files (schematic + PCB): https://drive.google.com/drive/folders/12NWG4p3mIAdmFKuxbu9VpJURFSAJRUav

Goal: Make the design fully functional and ready for production (Rev 2 fix).

Bonus (if possible):

Optimize for low power consumption Improve robustness for real-world usage (gym environment)

Please let me know your experience with ESP32, USB-C design, and battery-powered systems.