[Ipodlinux-devel] serial drivers (remote control and piezo)

[Bernard L. <le...@bo...>]

Hi all,

Seems I was a little hasty with the latest patch.  Today I had a look at
building the serial drivers to try out the remote control and the
piezo.  After about 1/2 of reading and 1/2 testing I had something
working!  This is why I really like Linux!

Anyhow I've just checked into CVS the code to get the serial ports
working.

/dev/ttyS0 is the remote control.  if you type "stty -F /dev/ttyS0 raw"
and then "cat /dev/ttyS0" and then press a button on the remote control
you should see output.

The data appears as so:

0xff 0xfd 0xf1 0x00
and repeats until you release the key
when you get
0xff 0xfd 0xf0 0x00

the 0xf1 part varies on the key pressed.
0xf1 -> play/pause
0xf2 -> volume up
0xf3 -> volume down
0xf4 -> fast foward
0xf5 -> rewind

You can't write to this this serial port and expect anything good to
come from it.

/dev/ttyS1 is connected to the piezo.
dd if=/dev/zero of=/dev/ttyS0 count=10 bs=1
should produce some noise.
if=/dev/urandom should produce a different noise.

stty -F /dev/ttyS1 speed 19200
will also change the noise.

Now does anyone know of a portable serial keyboard that works with only
a TX line? :)

enjoy,
bern.