killswtch's Home Automation and Media Projects
This is the story of my attempts at integrating various technologies into a 3-bed semi, constructing as much of the hardware and electronics as possible myself.
Saturday 10 May 2008, 8:38 PM
Hitch with the audio system
Today I started development of the software to control the whole-house audio system. It’s written in C# and based on the MiniHttpd project - a small but powerful implementation of a web server in C#.
However, when it came to testing the first bits of code, I’ve envountered a problem. A while ago I bought a 4 port RS232 serial card to go into boron, because the motherboard only has 1 onboard port which isn’t enough for the UPS, the matrix switcher and probably some other things such as connections to network switches.
The new card shows up fine in lspci, seems to be ok when running setserial -gb, but when trying to send or receive data nothing happens. Thinking it might be a conflict with the onboard port, I went into the BIOS and disabled it. Still nothing. So I swapped the card into another machine and re-enabled the onboard port in boron’s BIOS. Now the onboard port doesn’t work either.
I’m going to contact the manufacturer of the card for some help. But for the onboard port I’m completely stumped. It too shows up in lspci and setserial -gb (though only when running using sudo, which wasn’t necessary before) but any attempts to use the port result in various I/O error messages. I was worried that the new card may have killed the serial communication capabilities of the matrix switcher and the UPS, but I’ve confirmed that at least the matrix switcher still works by connecting it to my test machine, iron.
If anyone thinks they might know what’s getting on, please get in contact via the comments for this post - I would be very greatful for any help.
Saturday 10 May 2008, 8:37 PM
Successful test of audio over CAT5
I have just successfuly tested transmission of near-line-level audio over the cat5 cables I’ve recently finished installing.
The amplifiers and matrix switcher have been installed for a while, but until now I’ve not performed any tests of sending audio from one part of the house to the matrix switcher, through the appropriate amplifier and out of the installed speakers.
I bought some 2m green cat5 cables off of ebay, but rather than use them as normally intended I cut one of them into two equal lengths.
After removing a length of the outer insulation at the cut ends, I attached 2 phono plugs to one length and a stereo 3.5mm jack to the other (with a little help from wikipedia for the correct pinout of the latter).
A multimeter was used to verify that there weren’t any shorts - wire-wrapping the connections was a little fiddly - before I plugged the cables in for testing.
The length with the phono plugs was connected to the matrix switcher and the RJ45 patch panel, and the other length was attached to the headphone output of a DAB radio in the kitchen and one of the 2 ports in that room.
The successful test is promising for the completion of this project. I have ordered and bid on 2 more sets of speakers for the dining room and kitchen, and the final amplifier will be ordered soon.
The software needs to be written to control the system, but I could probably do most of that in a weekend. A little more hardware in the form of a touchscreen capable low-power computer and an iPod Touch will be required to run the web-based front-end for the software. Then the system should be complete.
Look out for a video demo of the system once I’m happy with it!
Tuesday 6 May 2008, 9:28 PM
Completing the data wiring
Today I added the final 4 network points - there are now a total of 24 around the house.
The wiring project started about 14 months ago, with the plan to have at least 2 network points in all rooms except the bathroom. The final distribution has ended up as:
Living room: 6
Dining room: 4
Kitchen: 2
Pantry: 4
Landing: 2
Bedroom 1: 4
Bedroom 3: 2
Despite considering that 24 ports might be a little excessive, I’ve come to realise that 24 ports isn’t quite enough especially when it comes to distributing analogue audio & video over CAT5 (i.e. not as IP data) since at least one port is required for each A/V combination depending on the quality of the signal desired. The living room should probably have 4 more ports, the kitchen could do with at least 2 more and a couple by the front door would come in useful for security purposes.
I’ve learnt a lot from the experience of doing this wiring, such as how to lift floorboards, that lathe & plaster ceilings are extremely fragile and plastering is nowhere near as easy as it looks.
Running the cables before moving in was certainly a good idea. It would have taken me probably another 12 months otherwise to get to this stage. It’s taken a lot more work than I expected, although the overall time is down to being in a lazy, bored and/or apathetic mood most weekends. I’m glad I did it though - the ports have come in useful for the MythTV system, for the family computer and soon enough the whole-house audio system. I’m also using them to trial some IP video cameras.
Tuesday 18 March 2008, 8:33 PM
Trunking and tray
I’ve finally managed to find somewhere to buy stuff to tidy up some of the cabling around the house. A couple of weeks ago I ordered some trunking and a cable tray (which will replace the improvised MDF/timber one I constructed from offcuts) from Minitran.
Unfortunately the first of two packages arrived late on a friday with only the larger items present - it appeared that the bubblewrap packaging (with no strong outer container) had disintegrated and spilled the smaller items somewhere along the delivery chain. The delivery company were mostly to blame for this, with the delivery driver not having the best attitude and the delivery not even being recorded on the paperwork which is probably why it was the last item to be delivered. The items should have been packed in something stronger but I guess such packaging is hard to come by for 3m x 30cm x 5cm consignments. I was also worried by the fact that my card payment had been manually entered into a PDQ machine, wihch suggests that my card number - submitted via the website - is being stored in plaintext somewhere. These days I would expect all online stores that accept card payments to do so via automated secured systems. Clearly this isn’t the case.
Anyway, I continued with installing what I had - the cable tray, a 3m length of 50×50mm trunking, and 2x 3m lengths of 25×38mm trunking.
The 50mm square trunking was used to tidy up the majority of cables that come through from downstairs. This required being fixed to the wall by screws, which wasnt too difficult. I used a hand mitre saw to make the 90 degree bends. I could have purchased corner joints, but they are over £7 each and would have gotten lost anyway. The mitre saw did a great job and the result looks neat.
After I had got the first lot of trunking installed I set to work on the cable tray. The tray is made from a steel wire mesh which is lighter than standard cable tray, looks fairly good and lets light through. The problem was, though, that I had to figure out how to securely mount it without using the steel rods and support brackets that had gone missing. I settled on doing what I had done with the improvised cable tray and used the picture rail to my advantage.
The tray had to be cut to size, about 50cm shorter than the 3m length. With the help of a dremmel this wasnt too hard. I initally left some spare length so that I could bend the wires around and then use them to fix the tray to the picture rail with screws. This didn’t quite work as I had hoped though. To bend the extra length I had to cut part-way through the wires and carefully bend them. I then intended to solder the bends to strengthen them up a little. This plan didn’t work, and I ended up removing the bent parts altogether.
Thanks to the tray being relatively light and strong it turned out that there was no need to fix it to the walls. Just resting on the picture rail keeps it secure enough.
The smaller trunking contains the cables from the other side of the house - from the pantry, bedroom 3 and the landing. This was self-adhesive so was a lot quicker to fit. The cables only just fitted inside though.
Once all of the trunking was installed, I re-ran all of the cables to the cabinet, tidying them as much as I could along the way. This involved lots of cable ties, spiral wrap and patience. As part of this, the remaining network cables were run to the cabinet and connected up to the patch panel. Unfortunatley the back of the patch panel is an unavoidable mess. At one point I thought of disconnecting, trimming and reconnecting the cables that were already connected but this proved far too difficult so I just tried to keep things as tidy as possible.
After clearing up the cables inside the cabinet, things look a lot neater in there (if you ignore the back of the patch panel). This makes it a lot easier to work around the back and portrays a more professional appearance.
Tuesday 18 March 2008, 8:31 PM
New amplifiers
Last month, as per my schedule of purchases, I bought 2 more amplifiers. These will serve zones 2 (dining room) and 4 (master bedroom). I ordered them from the same place as the first, despite having a rather unpleasant experience with the trader on eBay thanks to their appauling checkout/payment system and problems with their UK bank account (they are based in Germany).
The first amplifier, for zone 1 (living room), is silver. I was a bit surprised to find that the 2 that I received were in black. I was hoping to get my rack looking tidy by keeping the same look throughout the cabinet. Black goes better with this scheme, but the silver one stands out now. To balance it out I’m hoping to get a silver one next. A note of appology was included with the amps, which includes a 5 euro discount on the next order. I probably won’t be getting the next amp for a while, to keep my budget under control having spent quite a bit on the matrix switcher.
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