Notes on using the Crystalfontz I2C panels (CFAH2004AC-TMI-EW)

This sequence seemed to work for initializing the panel.

	delay 500ms            Probably not needed but can't hurt
	Send the byte 0x38     Function Set: 2 lines
	delay 120us
	Send the byte 0x0f     Display on, cursor on, cursor blinks
	delay 120us
	Send the byte 0x01     Clear display
	delay 15ms
	Send the byte 0x06     Entry mode: cursor shifts right
	delay 120us

Commands sent to the Crystalfontz I2C LCDs are a two byte transfer that consist
of a control byte followed by a command byte containing the command value.
Control byte has bit 7 (Co) set to 1 to indicate more commands can follow, and
bit 6 (A0) cleared to 0 to put the data value in the command register, so this
should be a 0x80 value.  The command byte is the normal command value used with
the HD44780 controller IC.  For example, the command to clear the screen is a
0x01.  To send this, the I2C write consists of two bytes: 0x80 (control byte
with Co=1 and A0=0) and 0x01 (clear command).

Data to be displayed on the LCD is sent with the control byte followed by any
number of data bytes containing the ASCII codes to be displayed.  Control byte
has bit 7 (Co) cleared to 0 to indicate more data to follow, and bit 6 (A0) set
to 1 to put the following bytes in the data register, so this should be a 0x40
value.  For example, to show "Hello", the I2C write consists of six bytes:
0x40, 0x48, 0x65, 0x6C, 0x6C, 0x6f.