How to enable FN+F7 / FN+F8 (brightness adjustment)

Here are a few easy steps to enable brightness toggle (tested on HP DV3510nr laptop)

install nvclock

sudo apt-get install nvclock

check whether nvclock is working fine

sudo nvclock -S -10
sudo nvclock -S +10

create file hpbrightnessdown.sh in the /etc/acpi folder with the following content

#!/bin/sh
/usr/bin/nvclock -S -10

create file hpbrightnessup.sh in the /etc/acpi folder with the following content

#!/bin/sh
/usr/bin/nvclock -S +10

create file hpbrightnessdown in the /etc/acpi/events folder with the following content

event=video LCD 00000087 00000000
action=/etc/acpi/hpbrightnessdown.sh

create file hpbrightnessup in the /etc/acpi/events folder with the following content

event=video LCD 00000086 00000000
action=/etc/acpi/hpbrightnessup.sh

ATTENTION video LCD 00000086 00000000 and video LCD 00000087 00000000 codes can be obtained by using acpi_listen in the terminal and pressing FN+(brightness up/down key)

run the following commands to make the files executable

sudo chmod +x /etc/acpi/hpbrightnessdown.sh
sudo chmod +x /etc/acpi/hpbrightnessup.sh
sudo chmod +x /etc/acpi/events/hpbrightnessdown
sudo chmod +x /etc/acpi/events/hpbrightnessup

run the following command to restart the acpid service

sudo service acpid restart

Voila

**Just tested on Macbook2,2 - Doesn't work - error: No nvidia card found on system!