HOW TO: Raspberry Pi, Raspbmc, Hyperion and a WS2801 Strip

After playing with Boblight for a while it looks like all the cool kids are moving to Hyerion, it has a GUI config editor, low CPU and a few more configuration options.

Hyperion documentation is also very strong, but I thought I might spell it out incase people are struggling a bit.

The developers are highly active to respond and help wherever they are.

Originally I moved from Boblight to Hyperion with a lightpack, I then added a second lightpack and ended up with a cable management mess, gaps in the LEDs and just a desire to get a bit better matching with the LEDs to screen output, rather than the 9 LED strips that are treated as 1 LED each (total of 10 LEDs).  The WS2801 LEDs allows them to be individually addressed.

Here’s how to do it….

Shopping List:

• 1 Raspberry Pi
• 1 WS2801 LED strip
• 1 Decent amped 5V Power brick
• Connectors
• Breadboard Jumpers

If you have some cash left feel free to  

1. Buy all the bits
2. Install Raspbmc
3. Install and Configure Hyperion
4. Cutting the LEDS
5. Placing the lights on your TV

1 – Buy all the bits

WS2801 strip

I bought a 5M strip of WS2801 5050 LEDs from a Chinese ebayer, on the decisions that they had:

• Black PCB background
• 5050 LEDs
• Had a power brick jack already on the LED strip

Unfortunately I dont really want to linkto the ebay seller or the item as I cant really reccomend the exact one I bought because it has the dreaded first LED blue issue and also one of the LEDs in the strip has a loose solder and one blue in one tri led doesnt always fire.  The other thing is the black PCB was for aesthetics, but the tape on the back is still white and I wanted the black as I have taped onto a clear part of the bezel on my Samsung TV.

So…… go source the LEDs from wherever you want, as long as they are WS2801, they will work (hyperion also supports other chips, but this is what I am using)

If you cant find one with a power brick jack, get one of these

Decent Amped 5V Power Brick

You will need some juice to drive lots of LEDs,  there are calculators to work out the exact amount of amps needed, but its a bit over my head, all I know is that the 5 volt, 8 Amp power brick I have is well above what I need to drive all 5 meters of LEDs.  The cost for a slightly less amped brick was negligable.

Heres the one I got – it allows you to put your appropriate country power plug into it – which I think is another advantage.  I use an old PC power cord.

Connectors

You will need a bit of soldering skill to use a strip round your tv as you will need to cut a strip and then join it at the corners.  I tried these connectors, but found they didnt connect properly, so I cut the ends off and just used the wires.  If you are no good with a soldering iron, there are corner connectors but I thought they looked a bit big and would give gaps in the leds in the corners.

Breadboard Jumpers

These are used to join the Pi with the LED strip grab a bundle of them so you can join them using the same colours all the way.

I go these ones but make sure you get male one end and female the other if you get other ones.

2 – Plug in the Bits

So this is where it might vary from your purchase.  If you dont have a led strip with a power brick jack, you are gonna have to work out how to wire it.  I didnt need to do this as my led strip already did, so all I need to do is plug the power brick into the LED strip.

Now for the connection to the Pi.

At this point we will leave the strip at 5M for testing.

Dont do any of this with your Pi or power brick on.

Go here and using the breadboard connectors hook up the Clock, Data and Ground wires , extend the bread board connectors by joining others on until you have the length you need between the pi and the LEDs but there is a limit so make this as short as possible.

Next join the female end of the breadboard connector to the data lead of the LEDs they should just plug in – but make sure you know which pins are which. you should be able to trace them back to the strip that should have each pin printed on the PCB.  make sure you get this right – if you push 5V through the data or clock pin your Pi will go to heaven.

Now you should have all the hardware set up ready for testing.

2 – Install Raspbmc

Download and install Raspbmc – this must be the July or later release
See http://www.raspbmc.com/download/ for instructions.

3 – Install and Configure Hyperion

Note: if you have boblight installed, you should disable it as the Boblight and Hyperion will fight with each other….

• Install WinSCP – Download Link
• Install PuTTy – Download Link

Ok so now we need to set up root access on the Pi this is needed (well, there are other ways but it makes it easier) so we can copy the config file to the \etc location on the Pi.  First we need to find out the Pi’s IP address

• On the Pi go to Settings -> System Info
• Note the IP address down

Next we need to SSH to the Pi and set root access

• Follow this guide to establish SSH access for the first time
• Follow this guide to set up root access

Now we can install Hyperion as root

• SSH into your Pi as root
• type:  apt-get update
• type:  apt-get install libqtcore4 libqtgui4 libqt4-network libusb-1.0-0 libprotobuf7 ca-certificates
• type: wget -N https://raw.github.com/tvdzwan/hyperion/master/bin/install_hyperion.sh
• type sh ./install_hyperion.sh

Now you need a configuration file.  You need a few things before you can copy the file to the Pi.  Download HyperCon from this link and read the wiki to configure it.  The example file on this page is for these LEDs.  You should be able to calculate how many LEDs are on your strip, but if your not sure, just use a small number to start with – remember this is just for testing at this stage 

Remember where you save the hyperion.config.json file.

Now we can copy the config file

• Connect to your pi using WinSCP, logging in as root and using the IP address you used above.
• navigate to /etc
• copy the hyperion.config.json file from above to this location

Reboot your Pi and you should be good to go for testing.

4 – Cutting the LEDs

Now you should have a working 5 meter strip of LEDs, its time to get cutting – work out where you want the cable start to be (for mine it was bottom left), them measure up the strip to the next corner and cut in between the copper contacts with a pair of scissors.  Mark the piece you just cut with the TV edge eg LEFT.  repeat this for the each corner of the TV.

Next, connect your pieces back together by either the solderless joiners, or what I did was cut the ends off the joiners (because they didnt fit properly) and solder the wires on to rejoin them.

Once done, put the LEDs on the back of your TV with blue tac so you can test how it looks.

5 – Tuning the Colours

To help calibrate, I created some videos to use.  The first three are pure red, pure green and pure blue, and then the last one has some movement of color with some pauses to help you with hscan and vscan on each strip (thanks to a YouTube publisher for this).

Feel free to download these, add them to your movie library and play them to see your results (and have a laugh at what the movie scraper uses from IMDB)

Link to Blue file

Link to Red file

Link to Green file

Link to calibration file (95mb)

You can pause and check the settings – go back into HyperCon, and make some adjustments to the colors, gamma and value settings.  Many hours will be spent in here – I suggest you make any changes in small increments.  Once you’ve make a change:

• Create the configuration file
• Using WinSCP, replace the existing config file
• Using PuTTY, log in and enter the command “restart hyperion”

Do this over and over again until you are happy with the color matching.  I recommend you also use things like Kids cartoons, dark scenes in movies and of course the avatar fire scene (and upload it at crappy quality to YouTube like everyone else).

Some things I found were dark scenes threw red and green out that I had to tune out, my whites were bluer than I wanted and some dark scenes had purple in them.

6 – Final Mounting

Once you have done all the testing you can bear, its just a case of removing the blue tac, and sticking the LEDs on the back of the TV with the 3M tape, hide the cables and sit back and enjoy your lights.

Hope this helps!

feel free to comment (and donate) if you found this useful.