Other Nokia N900 tips

When using EMMS to play music in GNU Emacs on the Nokia N900 via the FM transmitter, the transmitter will let out a periodic beep every couple of seconds.

This is done when the transmitter is transmitting and not playing music, as a reminder that the transmitter is on. The FM transmitter does this even when GNU Emacs is playing music as apparently the N900 is not aware of the music stream.

To disable this annoying beep:

• On the N900:

  # echo "echo 0 > /sys/bus/i2c/devices/2-0063/tone_deviation" > /usr/local/bin/n900-fm-transmitter-beep-disable.sh # echo "echo 0 > /sys/bus/i2c/devices/2-0063/tone_frequency" >> /usr/local/bin/n900-fm-transmitter-beep-disable.sh # echo "echo 0 > /sys/bus/i2c/devices/2-0063/tone_off_time" >> /usr/local/bin/n900-fm-transmitter-beep-disable.sh # echo "echo 0 > /sys/bus/i2c/devices/2-0063/tone_on_time" >> /usr/local/bin/n900-fm-transmitter-beep-disable.sh # echo "echo 120 > /sys/class/i2c-adapter/i2c-2/2-0063/power_level" >> /usr/local/bin/n900-fm-transmitter-beep-disable.sh # chmod 755 /usr/local/bin/n900-fm-transmitter-beep-disable.sh

note: the 120 line increases FM transmitter output, this is especially useful when plugging a USB charger in, since the N900 will by default decrease the output power, i.e. volume, increasing the static.

• On the N900:

  # echo "user ALL = NOPASSWD: /usr/local/bin/n900-fm-transmitter-beep-disable.sh" > /etc/sudoers.d/n900-fm-transmitter-beep-disable

• On the N900, add the following code to ~/.emacs

  (defun jj/n900-fm-transmitter-beep-disable () (interactive) (shell-command "sudo /usr/local/bin/n900-fm-transmitter-beep-disable.sh"))

When you want to disable the beep: