I'm developing a small micro-ohm meter that I will be powering from USB, due to the ubiquity of USB power bricks and computer power.
I've run into a few questions:
What do I do with the data lines of the USB? I'm not using them, I'm just interested in USB power, should I tie them to ground, to each other, to +5V?
Do I need to switch from "low power mode" to "high power mode"? This seems to indicate that you need to ask for high power using something called "enumeration", but the same article also talks about a 2.25W max... which I know is no longer true.
Max capacitance for the USB 2.0 specification according to the above is 10µF. I've got significantly more than that. This leads me to believe that I should be using something like the NCP380, MIC2545, or TPS2112. These are high side switches that can limit inrush current, allowing me to have more capacitance after the switch. Is this still necessary? Or has the capacitance limit increased since the above linked document was written?