This project takes an existing tool — the Hakko FX-901 cordless soldering iron — and adds USB charging and a beefy Lithium Ion battery inside a 3D-printed pack. I keep this little iron around for cosplay electronics emergencies, and adding USB charging means there’s less to pack…it uses the same phone charger and USB cable I’m already carrying.
This little USB port go-between is like a speed gauge for your USB devices. Instead of hauling out a multimeter and splicing cables, plug this in between for a quick reading on how much current is being drawn from the port. Great for seeing the charge rate of your phone or tablet, checking your battery chargers, or other USB powered projects.