NEW V3.0 USB INTERRUPTOR (09/08/2019)

New revisions of this board are 3.3V friendly! You can control the interruptor programmatically using either a 3.3V or 5V microcontroller! There are also two enable pins broken out - choose one to your liking.

What is it?

The USB power micro wedge board plugs inline with a USB cable. It normally passes the 5V power and always passes the USB D+/D- signals. When you press the button, the 5V power is momentarily disconnected.

The USB power micro wedge sits on the high side of the USB circuit. This means you can have your other test equipment like UARTs, Bus Pirates, uCurrents, or oscilloscopes monitoring your device under test, as if the micro wedge wasn't there.

Alternatively, a pin is broken out to connect to a microcontroller so the power can be disconnected programatically.

Why did you make it?

I work with USB devices as my day job. I play with IoT devices as a hobby. Re-plugging a USB cable gets really annoying. I know it is for most people as well, so here's a simple circuit to do the job.

This is a useful board for lazy USB/IoT device developers and/or test automation.

You could even use this board with a cron task to disconnect the power to your iPhone or Android to save your battery :)

How to use it

The micro USB connector is the input and the USB A connector is the output. Press the button to momentarily interrupt the 5V power. It's pretty simple to use!

The USB power micro wedge can handle up to 1.5A of current with 1.0A of continuous current. Play safe when living dangerously.

Use shorter USB cables to minimize voltage drop if your device under test is sensitive to such things.

If you have a micro controller or FTDI UART in bit-bang mode that shares the same GND as your USB device, then you can use it to programmatically switch the USB power micro wedge

Versions prior to 3.0 have a break out pin that is 5V active high. Pulling this pin low will disconnect the 5V until your controller pulls it back high.

All versions that now ship are 3.3V friendly. Connect the break out pin to a 3.3V or 5V source. Pulling the pin low will interrupt the USB power.

I personally use this connected to my FTDI UART's RST pin and use picocom to toggle the wedge.