i2c_puppet-Linux/LINUX.md

I2C Puppet mods for Linux systems

The original version lacked certain characters, such as , and the characters "<>{}[]^&%=" which made it difficult to use on Linux systems

This version of the firmware has been modified to support Linux systems. The following changes have been made

• The backspace key works during the GUI login
• The Sym key not acts as a Control key, so SYM+C is Control-C
• The four top button keys are now used to provide the missing characters.

The original definiton of the keys were this

	L1	L2	R1	R2	SPKR	Mic	BS	NL	SPACE
					$	~	\b	\n
Alt					`	0
Shift					$
Sym					$			|

This firmware adds the following mappings

	L1	L2	R1	R2	SPKR	Mic	BS	NL	SPACE
		%	=	\	$	~	\b	\n
Alt	>	]	}	&	`	0
Shift	<	]	{	^	$	~	\b
Sym					$	~	\b	|

Linux Debug tips

The keyboard was two "outputs" - one is the USB HID interface, the other is the serial port. Any printf() command goes to the serial port.

When the keyboard is plugged into a Linux system, a new TTY interface will appear. I usually use "ls -lt /dev/tty* | head" to learn the name, as the newest port will appear first. On my system, it's /dev/ttyACM0

So on one terminal, I type

cat -v </dev/ttyACM0

while on a second terminal window, I type

cat -v

The first one will print all of the printf output, and the second will show you how the keyboard works normally.

Compiling firmware on Linux

I edit the files in /ic2_puppet/all/ using my preferred editor. In my case, I use emacs. I have the keystroke combination "Control-C M" bound to compile, using

(global-set-key "\C-cm" 'compile)

And when I press these keys, emacs saves all files, and recompiles the code. I have a small hub with switchable on/off ports, and restart the keyboard into boot mode, and then do a "make install" to load the new firmware

TODO

Currently - the SYM+Button keys are defined as the character "x" to indicate it's not been specified. I'l like to make these keys to the 4 arrow keys.

Also - it might be possible to create key combinations by combining the modified keys, like SYM+Alt+key