USB-C Power Meter

Measuring USB device power draw on the bench usually requires juggling a meter, breakout boards, and loose wiring. This project packs voltage/current sensing and a live display into a compact custom PCB with USB-C pass-through.

• —Two-layer KiCad PCB hosting Nano + INA219 + OLED
• —USB-C input/output with CC configuration
• —Real-time voltage, current, and power display
• —Validation against lab instruments

USB-C in → sense path (INA219) → USB-C out, with an Arduino Nano reading I2C measurements and rendering them on an SSD1306 OLED.

Custom 2-layer PCB in KiCad integrating:

• —Arduino Nano footprint
• —INA219 high-side current/voltage sensing
• —SSD1306 OLED (I2C)
• —USB-C connectors with CC configuration
• —Precision sense resistor and supporting passives

Embedded firmware samples the INA219 over I2C and updates the OLED with voltage, current, and computed power at a readable refresh rate.

• —INA219 for integrated shunt amplifier + ADC
• —Two-layer board to keep fabrication simple and inexpensive
• —OLED for a self-contained instrument without a host PC

Measurements from 0–5 V and up to approximately 630 mA were cross-checked with oscilloscopes and multimeters.

Delivered a working USB-C power meter PCB with live OLED readout and instrument-validated measurements in the tested range.

• —USB-C CC configuration correctness
• —Layout of the sense path for accuracy
• —Mechanical fit of connectors and display

Even a “simple” meter benefits from careful Kelvin-ish sense layout and a clear bring-up checklist against trusted instruments.

• —Higher current range and protection
• —Data logging over USB serial
• —Expand the interactive 3D board presentation with annotated callouts