First, you’ll need to
set the serial port to the bootloader
. But that port is
only visible when the board is in bootloader mode, so pull the reset line low
twice quickly to invoke the bootloader reset feature discussed above. On
Pro Micro’s, or other devices which don’t have a reset button, you can
either use a wire to quickly short ‘RST’ to ‘GND’ twice, or wire up a
temporary reset button.
While the Pro Micro is in the bootloader
change
the ‘Tools > Serial Port’ menu to the bootloader COM port. Quick! You’ve
only got eight seconds. On Windows, the bootloader’s COM port number is
usually one number higher than the Pro Micro’s regular port number.
With the serial port set, we’re just about ready to re-upload our sketch. But
first,
double check that the board is correctly set
. Then
reset to
bootloader again
, and quickly upload your sketch. Again, you’ll have to be
quick…you’ve only got eight seconds. It may help to press the Upload
keybind – CTRL+U / CMD+U – immediately after resetting.
It can take a few tries to get the timing right. Since the code has to compile
first, it may help to
hit upload first
and then reset.
Frequently Asked Questions
If you’re having technical difficulties with your Pro Micro or Fio v3, see if any
of the answers to these FAQs help. If not, please get in touch with our tech
support team.
What are VID and PIDs?
VID is short for ‘Vender Identification’ and PID is short for ‘Part
Identification’. In other words, this pair of IDs defines the device. This is
how your computer knows what you’ve plugged in, what drivers to use with
it, what COM port is assigned to it, etc. All native USB devices have a
VID/PID.
All SparkFun ATmega32U4 boards share the same VID – 0x1B4F, and
they all have unique PIDs. 5V Pro Micros lay claim to PIDs 0x9205 and
0x9206 (one for the bootloader, one for the sketch). 3.3V Pro Micros will
show up as 0x9203 and 0x9204 for bootloader and sketch, respectively.
And the Fio v3 has 0xF100 and 0xF101.
How Can I Change the VID and PID on an ATMega32U4
Board?
Every time you upload code the VID and PID are uploaded to the device.
These values are located in the ‘boards.txt’ file and will therefore be
determined by the board you have selected. Keep in mind that if you select
the wrong board you will get the wrong VID/PID uploaded which means the
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