Once assembled and flashed, the PD Logger is very straightforward to use.

1. Connect it between a USB-C charger and the device you want to power. In this example, I tested it while charging a tablet.
2. As soon as the charger negotiates with the load, the PD Logger powers up and joins the local Wi-Fi network.
3. Open a browser and go to pd-logger.local (or the device’s IP address). You’ll see a simple web page that shows the current voltage, current, and power. The values update automatically every 5 seconds.

But the Logger can do more than live readings. All measurements are stored locally for several hours. By opening the /graphics page in your browser, you get interactive plots for voltage, current, and power over time.

This makes it easy to analyze charger stability, load behavior, and even spot small fluctuations. The Y-axis auto-scales, so sometimes the variations look dramatic—but a closer look at the scale often reveals that the changes are tiny.

Finally, the Logger also provides a CSV export button, so you can download the data and analyze it further in tools like Excel or Python.

With this setup, any USB-C charger becomes a transparent, measurable power source—and all you need to access the data is a web browser.