This is a small project to connect a AVR microcontroller
(e.g. an "Arduino") to the LCD/Button panel of a Cobalt RaQ3.

I own one of these devices on which the mainboard was unfixably
broken, and I decided to use them as a general purpose case.

Pinout of the 26pin ribbon connector to the frontpanel, with
proposed connection to an AVR Mega168/Arduino:

--------:-----------:----------------------------:------------:---------
Button  |LCD/245    |Arduino/AVR          Ard/AVR|LCD         |Button
--------:-----------:----------------------------:------------:---------
                            +-----------+
            '245 \OE PB5(13)| ( 2) ( 1) | PB3(11) LCD_E(p6)
         LCD_VCC(p2)        | ( 4) ( 3) |         GND
         LCD_D0(p7)  PC0(A0)| ( 6) ( 5) | PC1(A1) LCD_D1(p8)    B_Pin
B_Left   LCD_D2(p9)  PC2(A2)| ( 8) ( 7) | PC3(A3) LCD_D3(p10)   B_Up
B_Down   LCD_D4(p11) PC4(A4)| (10) ( 9) | PC5(A5) LCD_D5(p12)   B_Right
B_E      LCD_D6(p13) PD6(6) | (12) (11) | PD7(7)  LCD_D7(p14)   B_S
         LCD_RW(p5)   GND!  | (14) (13) | PB4(12) LCD_RS(p4)
              n/c           | (16) (15) |         GND
         Col (Cath)  PD5(5) | (18) (17) | PB0(8)  Web  (LED Anode)
         Link(Cath)  PD4(4) | (20) (19) | PB1(9)  Disk (LED Cath)
         100M(Cath)  PD3(3) | (22) (21) |         n/c
         TxRx(Cath)  PD2(2) | (24) (23) | PB2(10) Logo (NPN base)
              n/c           | (26) (25) |         n/c
                            +-----------+

LCD_x are connections to the hd44780-LCD (with pin numbers in
parentheses). B_x are connections to the buttons. They are put
on the D1..D7 lines when the \OE pin is low (there's a 74HC245
on the frontpanel board). LEDs are all wired up differently:

The network LEDs (Col, Link, 100M, TxRx) have their anodes
wired up to Vcc and expect to be pulled low with a suitable
resistor (say 200Ohms - 1kOhm for 5V). Web has the cathode wired
to ground, Disk has the anode wired to Vcc. Resistors are soldered.

Serial protocol (on an Arduino, this is the USB emulated serial port
/dev/ttyUSBn):

	By default every character gets sent to the LCD.

	The following ESC sequences are understood:

	ESC 'c'           -> clear and home
	ESC 'h'           -> home
	ESC 'p' x y c b   -> goto x y, turn on/off cursor and blink
			x = '0'..'9' and 'a'..'e'  -> x-position in hex
			y = '0'..'1'               -> y-position in hex
			c = '0'..'1'  show(1) or hide(0) cursor
			b = '0'..'1'  blink(1) or don't blink (0)

	ESC 'u' x p0..p7  -> user-define character
			x = '0'..'7'  character number in hex
			p0..p7   character data in BINARY!

			A single 5x7 character looks like:

				p0_bit4 p0_bit3 ... p0_bit0   <--- top
				p1_bit4 p1_bit3 ... p1_bit0
				...                   ...
				p7_bit4 p7_bit3 ... p7_bit0   <--- bottom

	ESC 'l' a b       -> LED, lights up the LEDs corresponding to
				the mask 0xab where
			a = '0'..'9','a'..'f' -> high nibble in hex
			b = '0'..'9','a'..'f' -> low nibble in hex

	ESC '?'           -> inquire, will return the string
				avr-cobalt-panel\r\n

The keys pressed on the front-panel are returned as:

	Up/Down/Left/Right/S/E -> 'U', 'D', 'L', 'R', 'S', 'E'
	The sunken button that can only be reached with a *PIN* is
	returned as the character 'P'.

Depending on desired use, you may want to disable the Arduino's auto reset 
on serial connect: http://playground.arduino.cc/Main/DisablingAutoResetOnSerialConnection
I added a 100uf capacitor between reset and ground and it worked. This allowed 
sending commands through echo (without it resetting).