Adafruit USB Power Gauge Mini-Kit

This USB port go-between acts like a speed gauge for your USB devices. It enables quick readings on current draw without needing a multimeter or splicing cables.

Useful for observing the charge rate of phones or tablets, checking battery chargers, or other USB-powered projects, this tool offers a practical solution. Plug it in between devices to receive real-time data.

Engineered with a reprogrammable micro-controller, analog output, and a TTL serial output, it supports debugging and datalogging while remaining open-source. Data passes through seamlessly, compatible with any USB device at any speed.

The power line is equipped with a 0.1 ohm current sense resistor and an INA169 high-side current sensor, tracked by an ATtiny85 chip. The microcontroller reads current draw and bus voltage, lighting up LEDs for a visual power consumption display—blue LEDs indicate power draw, while a green LED warns of voltage droop.

Capable of supporting up to 2 A of current, it measures currents up to 1 A and provides readable voltage, current, and wattage data on the TX pin at 9600 baud. It is an ideal choice for datalogging or plotting with compatible devices.

The mini kit includes an assembled and tested PCB, a USB jack, and a plug. Assembly requires minimal soldering and can be completed in minutes, offering flexibility for more advanced users who may opt to splice it into a cable.

This device is handy but not a multimeter, with an assumed variance due to noise and other factors, intended for basic guiding rather than precise laboratory data.