ls -l /dev/disk/by-uuid/
sudo mkdir /media/usb
sudo chown -R pi:pi /media/usb
To manually mount the drive use the following command :
sudo mount /dev/sda1 /media/usb -o uid=pi,gid=pi
fstab entry:-
UUID=1085-BD48 /media/usb auto,users,rw,uid=pi,gid=pi 0 0
# -t {vfat|ntfs-3g|ext3|ext4}
...
...
XMMS
as root.... which is never a good idea.....
echo "deb http://p.quinput.eu/debfarm unstable all" > /etc/apt/sources.list.d/99quinput.list
aptitude update; aptitude install xmms
Little Pi Screens
This is on hold for a bit, I had purchased a 600x480 capacitive touchscreen from adafruit, but the kernel needs the modules recompiled in to it, and as the new raspberry pi2 has an updated kernel to enable the new quad core, there is a conflict. I'm guessing (Richard Burton Voice) minds immeasurably superior to mine will have the matter in hand and will resolve this in time.
Enable Usb Audio
The audio section on the raspberry pi is reported to be quite poor. My own findings are that it isnt too bad but there is quite a bit of digital noise present and there is a pop as you start or stop music which is attributed to poor driver programming. In time this may be resolved but if audio is played thrugh anything like a hifi amp or a public address, then a better quality option would be to use a usb sound card of sorts. There are lots of different types, and some are very cheap dongles, but I have settled on using THIS type using a PCM2704 chip. It doesn't need drivers or kernel compilation, it is usb powered drawing around 75-100mA via a proper usb cable and it also has audio digital coax and optical toslink outputs which is nice as I have an option to use a fibre optic cable and electrically isolate the audio source getting rid of all kinds of power supply noise and earth loop hums. the normal audio is a 3.5mm stereo line out. I paid around a fiver for just the pcb version which I then wrapped in heatshrink, but THIS is the same thing in a little box for a little more.
Rasbian by default enables the onboard output by default and I think the best way to configure it is to prioritise the usb first and then the onboard output if the usb audio module is not detected. HDMI can also be used with an HDMI audio breakout box which you can investigate yourself.
sudo vi /etc/modprobe.d/alsa-base.conf
or
Turns out the file is now called alsa.conf and is found in
/usr/share/alsa. Changed the lines:
defaults.ctl.card 0
defaults.pcm.card 0
to card 1 and that's me up and running.
Pi Power over Ethernet
Should I explain what PoE is? Maybe I should just keep it short. It is a way of supplying power on the unused wires in ethernet cable along with the connection to the network. Ethernet cable is also comparatively cheap. I have put a Raspberry Pi and an IR camera in a remote location 500 meters from a power supply and used these passive PoE injectors (which seperate the power back out to a power plug). In this example, I ran 24v dc from an old laptop switchmode PSU over 250 meters of cat6 ethernet cable to a small network switch to act as a repeater. A network signal on Cat6 will reach 300 meters easily but a full 500 meters is a stretch. I used PoE injecctors to supply the network switch with 12v via a cheap small 3 amp buck convertor (example) and re-inject the 24v back in to another 250 meters of cat6 until we reach the raspberry pi. Another Buck convertor then drops the voltage to the required 5v to run the pi. I use 24v on the PoE because a smaller voltage such as 12v would struggle to make it to the other end. The heigher the voltage the further it will travel. This is one of the reasons pylons carry up to 128,000 volts across the country. A previous trial of pushing 12 v over 100 meters only gave me 10v at the other end. The buck convertors give a nice clean supply to the unit at close range. Some official standards specify 48 volts and this would be better but the buck convertors maximum input is 28 volts and I just happened to have a nice beefy 12 amp 24 volt laptop psu available.
In this diagram, the data is carried by o, O, g & B. The power pin (+) is carried by both b & G, the outer collar (-) of the power plug is carried by both br & BR.
I'm wondering how far I can reliably repeat and carry the 24v and run multiple switches and pi. Cat5e cable is rated at 25watts per twisted pair. which equates to 5 amps at 5v or 1 amp at 25 volts. I think I could quite happily run maybe 2 picameras, an IR light and a network switch over 1 length. Alternating current travels further, I could try 24vac and use a simple bridge rectifier and electrolytic before a regulator.
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