Pro Micro & Fio v3 Hookup Guide
Getting the Pro Micro or Fio v3 set up on your computer and in your Arduino environment can be difficult. Follow along on this page for a step-by-step guide through the driver installation and Arduino-enabling process.
Windows Driver Installation
Step 1: Download the Driver
Before plugging your board in, get a head start by downloading the drivers. The same driver file works for both the Pro Micro and the Fio v3.
Unzip that zip file, and don’t forget where you’ve left its contents. In that zip file, you should find an INF file, which contains all the information Windows needs to install the Pro Micro’s driver.
Step 2: Plug in the Pro Micro / Fio v3
When you initially plug the board in, an “Installing device driver software” bubble notification should pop up in the lower-right corner of your taskbar. After the green dot circles the grey box a number of times, you’ll probably get a sad bubble like this:
Never fear! Windows just doesn’t know where to find our driver.
Note: Some users have experienced issues when plugging the Pro Micro into a USB 3.0 port. If you experience issues on USB 3.0 ports, try switching to use a USB 2.0 port.
Step 3: Open the Device Manager
From here, the most straightforward way to install the driver is through the Device Manager. To get to the Device Manager, click the Start button, then open the Control Panel. In the Control Panel, click System and Maintenance, and then open the Device Manager.
Alternatively, you can open the Run prompt (Windows key+R) and type ‘devmgmt.msc’ and click OK.
In the Device Manager, expand the ‘Other devices’ tree, where you should find a ‘USB IO Board’ with a yellow warning sign over its icon. Right-click the ‘USB IO Board’ and select Update Driver Software….
This should spawn an ‘Update Driver Software - USB IO Board’ window.
Step 4: Finding the Driver
In the first window that pops up, click ‘Browse my computer for driver software’. On the next window, click ‘Browse…’ to search for the driver you just downloaded. It should be a folder named ‘SFE32U4_Drivers’. After you’ve selected the ‘driver’ folder, click OK, then select Next.
Windows will attempt to do its driver install thing, but not before complaining about the driver being unsigned. It’s safe to select ‘Install this driver software anyway’ on the warning dialog.
After watching the progress bar beam by a few times, you should get a happy ‘Windows has successfully updated your driver software’ window. And the ‘Device Manager’ should have a new entry for the ‘SparkFun Pro Micro (COM ##)’ (or ‘SparkFun Fio V3 (COM##)’ if you have one of those) under the ‘Ports’ tree.
Take note of which COM port your Pro Micro was assigned. We’ll need it soon.
Installing the Arduino Addon
We’re still not completely ready for Arduino, but this is the final stretch. Before you can use the ProMicro in the Arduino IDE, you need to enable it and activate some super-secret Arduino files.
To begin, download this zip folder, and unzip it into a ‘hardware’ directory within your Arduino sketchbook.
Where’s your Arduino sketchbook? Well, by default, it should an ‘Arduino’ folder in your home directory, but to double check you can go to ‘File’ > ‘Preferences’ within Arduino and check the ‘Sketchbook location’ text box. Just make sure you close all Arduino windows once you’re done.
Once you’ve unzipped that folder into the ‘hardware’ folder within your Arduino sketchbook (you may actually have to create a hardware folder), your directory structure should look something like this:
There’s a lot going on in that addon, but one of the most important files is ‘boards.txt’, which will add a few new entries to your ‘Tools > Board’ menu.
To double-check that the board definitions have been added to Arduino, open up Arduino, and check under the ‘Tools > Board’ menu. There should be some new entires for ‘SparkFun Pro Micro 8MHz/3.3V’, ‘SparkFun Pro Micro 16MHz/5V’, and other 32U4 boards.
Notice there are two options for Pro Micro - 8MHz and 16MHz. It’s very important that you select the Pro Micro option that matches your board’s voltage and speed. Don’t know which board you have? Check the bottom of the board, where you should find either a ‘5V’ or ‘3.3V’ box checked.
You should also see your Pro Micro’s COM port under the ‘Tools > Serial Port’ menu. Select it, and head over to the Example 1 page where we’ll upload our first piece of code.