I was finally able to get this part to work after quite a bit of difficulty by following some tips I have seen elsewhere. My notes in case it helps someone else.
Environment: Windows 7 64 bit Arduino 1.0.5
Get the driver zip mentioned in the “Getting Started Guide”. Copy the single file within it to c:\windows\inf, it will ask for administrator permission to do so.
From the same page, get the Arduino addon files and install them as instructed. Start Arduino, go to File/Preferences and turn on “Show verbose output for: ” for both compilation and upload.
Connect a jumper wire to one of the gnd pins and be ready to touch the other end to the rst pin. For me, I just slid the end of the jumper wire into the gnd hole and held it in place diagonally so it was touching, then touched the other end to the rst hole as needed.
I did this first, but I don’t know if it is necessary. I plugged the board into USB, heard the USB connect bing (low note followed by high), then about 7 seconds later, got a USB malfunction message and a USB disconnect bing (high note followed by low). During that 7 seconds, the part was recognized in the Device Manager as a Sparkfun Pro Micro.
Now for the final step: Start Arduino, select Sparkfun Pro Micro 3.3V, and double-tap the reset pin. During the 7 seconds, you should be able to select the correct serial port in Tools/Serial port. Now load an example sketch, I selected File/Examples/04.Communication/ASCIITable which just uses the USB serial port, no other hardware or D13 light needed. Push the upload button, then watch the status window. It will do something to the effect of
PORTS {COM7, } / {COM7, } => {} PORTS {COM7, } / {COM7, } => {} PORTS {COM7, } / {COM7, } => {}
a lot, maybe 15-20 times in about 4-5 seconds. Towards the end of that time, double-tap the reset pin. If it works, avrdude will print a lot of text, report success, and the part will work normally from then on. Too late on the double-tap and it will not find the device, too early and the 7-second window will expire before avrdude gets into contact with the bootloader and holds the window open.
Here’s what I think is happening: I have seen notes on the net to the effect that a poorly behaving sketch can effectively crash or block the USB driver in the device, and never let the bootloader do its work. The reset double-tap forces the bootloader to start, wait 7 seconds before starting the user sketch, and if Arduino starts a sketch upload during that time, then things work normally. Outside of that window the broken user sketch blocks things. So, the question then becomes, how did a bad sketch get into the part in the first place? I had this trouble with a part fresh from Sparkfun, which I had never put a sketch on.
Hope this helps someone out there…