NOTE: Bumble-B firmware is a modified version of the "userial" program from Thomas Pircher.
See http://www.tty1.net/userial/ for details.

Bumble-B Firmware
-----------------
This is the default firmware driver that ships with Bumble-B.

It is a virtual serial CDC driver that enables I2C, SPI, and general purpose IO
using text commands.

The software is based on userial.
See http://www.tty1.net/userial/manual/userial.html for details and command set
documentation.


Notes
-----
pca9555.ser included in the distribution contains some example userial commands
that drive a PCA9555 port expander.


Issues
------
The i2c driver included with userial doesn't work with the at90usb162, so it
was replaced with Peter Fleury's i2cmaster library. This library doesn't have
runtime control over the speed of i2c, so in the "IC[freq]" command, the
frequency value is currently ignored. An IC[freq] statement will otherwise
initialize the i2c subsystem normally.


---------------------
0.4 UPDATE 10/27/2009
---------------------
Fixed GPIO bug stopping ports C and D from working properly. Updated version
strings to say BumbleB firmware rev #. Moved this file to README inside the
distribution (used to only exist on the website). GPIO read was using PORT
intead of PIN, so not actually reading the pin, but rather the Hi-Z /
pull-up configuration bit. Updated Windows .inf with new version strings and
fixed a bug in it.


---------------------
0.3 UPDATE 08/10/2009
---------------------
Bug in GPIO. Port A was mapped to C, port B was mapped to D, and port B was
inaccessible. All ports answ


---------------------
0.2 UPDATE 08/06/2009
---------------------
The prototypes used an 8Mhz crystal, and the F_OSC setting was mistakenly
configured for that. Changed to 16Mhz.