USB Host Shield for Micro

Hoping someone can point me in the right direction. I'm new to the whole hardware thing, and wouldn't have a chance developing something at this point, so I'm hoping it exists.

I started my arduino experimentation because of a need that I could not find a solution for. Reading a value off of a USB scale on keypress and transmitting as keystrokes to the computer. pretty simple once I did my research I went and got a leonardo and a USB host shield, added in a button tossed the thing into an enclosure, few lines of code and presto. worked great. I know the rating doesn't specifically allow for just the 5V usb connection, but as of my testing so far I haven't had to add external power to push it to the 7V.

Now my mission is to simplify it. The ultimate goal would be to get this to a single small board solution with a small nubmer of components so I could have several hundred of these made. But to start down this path I got a Micro, which seamed like an obvious move from the Leonardo. I also picked up a gravitech USB shield for Nano. which made sense as the pinout matches the Micro with the micro having a few extra pins that the nano wouldn't pass to that shield (I don't know if this will hold true or not as I haven't made it far enough to be able to fully test).

Then I hit my first problem. Gravitech board didn't use the 5V, so I added a 9V battery pack to the 7-12V input. that powered up the shield, but didn't pass enough power to my scale to keep it on. it would turn on, zero, then enter a sleep mode. I think i could continue forward by powering the scale with batteries, but then I'll be using even more batteries that i don't really want. Considering the Leonardo with full sized USB Shield can be powered and communicate without any problem, including completely powering the scale, I can't imagine there is a technical reason why a shield on the Micro couldn't do the same.

I also came across the USB Host Shield for Arduino Pro Mini, and some info on how this could be made to work with with a 5V connection, but is certainly not the stack and go solution I was hoping for.

Ideally someone can point me to a solution to at least get down to the micro format. However any pointers that would help me move forward would be appreciated.