Day: September 15, 2025

DIY USB-C PD Tools

USB-C PD Decoded: A DIY Meter And Logger For Power Insights

September 15, 2025 by 9 Comments

As USB-C PD becomes more and more common, it’s useful to have a tool that lets you understand exactly what it’s doing—no longer is it limited to just 5 V. This DIY USB-C PD tool, sent in by [ludwin], unlocks the ability to monitor voltage and current, either on a small screen built into the device or using Wi-Fi.

This design comes in two flavors: with and without screen. The OLED version is based on an STM32, and the small screen shows you the voltage, current, and wattage flowing through the device. The Wi-Fi PD logger version uses an ESP-01s to host a small website that shows you those same values, but with the additional feature of being able to log that data over time and export a CSV file with all the collected data, which can be useful when characterizing the power draw of your project over time.

Both versions use the classic INA219 in conjunction with a 50 mΩ shunt resistor, allowing for readings in the 1 mA range. The enclosure is 3D-printed, and the files for it, as well as all the electronics and firmware, are available over on the GitHub page. Thanks [ludwin] for sending in this awesome little tool that can help show the performance of your USB-C PD project. Be sure to check out some of the other USB-C PD projects we’ve featured.

Continue reading “USB-C PD Decoded: A DIY Meter And Logger For Power Insights” →

Neural network shown on original mac screen, handwritten 2 on left and predictions on right

Original Mac Limitations Can’t Stop You From Running AI Models

September 15, 2025 by 14 Comments

Modern retrocomputing tricks often push old hardware and systems further than any of the back-in-the-day developers could have ever dreamed. How about a neural network on an original Mac? [KenDesigns] does just this with a classic handwritten digit identification network running with an entire custom SDK!

Getting such a piece of hardware running what is effectively multiple decades of machine learning is as hard as most could imagine. (The MNIST dataset used wasn’t even put together until the 90s.) Due to floating-point limitations on the original Mac, there are a variety of issues with attempting to run machine learning models. One of the several hoops to jump through required quantization of the model. This also allows the model to be squeezed into the limited RAM of the Mac.

Impressively, one of the most important features of [KenDesigns] setup is the custom SDK, allowing for the lack of macOS. This allows for incredibly nitty-gritty adjustments, but also requires an entire custom installation. Not all for nothing, though, as after some training manipulation, the model runs with some clear proficiency.

If you want to see it go, check out the video embedded below. Or if you just want to run it on your ancient Mac, you’ll find a disk image here. Emulators have even been tested to work for those without the original hardware. Newer hardware traditionally proves to be easier and more compact to use than these older toys; however, it doesn’t make it any less impressive to run a neural network on a calculator!

Continue reading “Original Mac Limitations Can’t Stop You From Running AI Models” →