The Power BLough-R Solves 5V USB Problem with OctoPrint and 3D Printers

Software developer Brian Lough encountered issues when using the OctoPrint web interface with his 3D printer, finding that when he turned the printer off, the LCD display would stay on. It turns out the PC he uses to host OctoPrint continued to provide 5V of power via USB connection to the printer even though its PSU had been shut off.

To get around the issue, Lough designed the Power BLough-R- a pass-through device for USB Type A connectors that strips the 5V line and features a male connector on one end, and a female on the other.

“There are other solutions to this problem, some people have taken to cutting traces on boards, others have modified the USB cable (either by cutting the 5V line or placing tape over the connector), but I thought this would be a nice, non intrusive way to achieve the goal.”

Lough is currently selling the Power BLough-R on Tindie, and as you might image, he has them produced in batches to keep the supply chain rolling. As with any mass produced PCBs, he needed a way to test them before shipping them out to his customers, so he designed the Arduino Automated Product Tester, which checks to make sure there is proper power throughput. The tester is a simple but ingenious design, the features an Arduino Nano housed on a Nano Screw Terminal breakout board with a pair of USB connectors wired to the platform.

Using the tester has drastically reduced the amount of time it takes Lough to check each unit, roughly 5-seconds using the Automated Tester vs. around 30-seconds to check each one manually using a voltage meter. For those who would like to build their own tester, Lough features the hardware required in the video description and the code to his GitHub page.