Data Communications

Once music is set, the patterns chosen, the lights rigged up, then its time for the computer to give commands to the system. Vixen sends signals out through the printer port on the computer into a special made cable that converts D25 pin layout to RJ45 pin layout. The RJ45 uses CAT5 cable similar to Ethernet/DSL/Internet connection cabling. This cable connects the computer to the sub processor boards (Grinchs) working in tandem. Having the signals sorted and divided into 32 groups of 4, each of the quad signals leave the Grinchs on a CAT5 heading toward the SSRs. Terminating at the SSR, the signal is broken down and sent to it own channel. For our system, we needed 33 custom made cables to reach outside to the various SSRs on the house and in the yard. Buying ready-made cables is too cost prohibitive so we made our own. A box of CAT5 cable can be bought at home supply centers for about 70 dollars per 1000 ft of cable. Buy a few more RJ45 cable ends than necessary in case of bad connections. Be sure to leave a bit of slack in the cable to prevent stretching it and in case you want to move your connection location as your display evolves.

Power Distribution

On a separate subsystem controlled by SSRs are the AC power lines. Trunk lines running out from the panel box terminate in GFI (ground fault interrupter) boxes to eliminate shock hazards and breaker tripping in the event of the lines shorting due to water penetration or line cuts. From the GFI boxes and heading out to the SSRs are extension cords made up from SPT2 wire. Each amount of current demanded from the string of lights is less than the rated load of the cord. On our system, we have 2 sets of trunk lines. One each coming from a separate panel box. Each GFI box has 2 or more GFI receptacle mounted in the box. A lot of cords running all over the yard leads to hazardeous conditions especially from snow and rain, so be sure to cover up any connections between cords with plastic wrap and securely tape closed. Keep connections off the ground if possible. Posting some warning signs like High Voltage ones will keep most curious onlookers off the grass.

System Layout - the long and short version

The entire system is actually a collection of subsystems each working together to create the blinky flashy effect associated with a good display. First, there is the computer to control everything and saying when to blink (or not to). The computer we use is just a standard Compaq computer off-the-shelf type. A specially made cable from the computer to the subprocessor boards sends signals from Vixen. The twin subprocessor boards are called Grinchs (the designer's favorite Christmas character and ours too)and are capable of controlling 64 channels of lights each for a total of 128 channels! (I want more channels) Each of the channel signals are routed outside to another board called a SSR (solid state relay) in groups of 4 channels. Each SSR then splits up the group of 4 channel signals individually and send the separate signal to its own channel to control a Triac circuit. A Triac circuit is an electronically controlled switch. Each string of lights on a particular circuit will all go on or off at the same time according to the signal sent to it from the beginning. Sort of the roots of a tree telling the leaves what to do kind of thing.

The Software

Running the show is a unique set of software called Vixen (named after the 4th reindeer on Santa's team). Every song is laid out in a grid with time along the top and channels of light down the side. Each section in the grid is called an event and is on for a period of standard time such as 100th of a second. Each event can have a light value ranging from 0% (off) to 100% (totally on)with any other value a function of ramping up or fading. This program is free of cost to download and free from viruses. You can get it at http://vixenlights.com
Believe me when we say that its easier to do the hardware for the display than to come up with choreography for 128 channels of lights. Others have said that it can take up to 4 hours of programming per minute of music but we have't reached that point yet. Don't be put off by this but it will take a lot of time to program your entire selections so don't wait for the last minute.

Musical Selections aka the Christmas Program

From the time we are little til we grow old, we hear various Christmas songs (which from time to time get stuck in our heads) that speak to us in different ways. Choices of songs can include childen songs to traditional church music to songs from television shows. The selection of songs of the display can be changed daily or not at all depending on what you like. Currently, we have about 30 songs we can choose from for the daily show. Hopefully, we would like to add another set of songs that are not directly Christmas related that can be played on a few nights to boost viewers. The Christmas Rock n Roll Show could be a feature to give your display some musical flexibility. Also audio tracks are not limited to music. Maybe you might want to add some Christmas comedy or voiceovers announcing some event or the like. Speakers set up in the yard and a FM transmitter is what we will be using to play our music. Please be aware there are noise ordinances in most communities so you might not need 100 Watt amplifiers to broadcast the Grinch song.

Let There Be Light!

After knowing how much power is available for use, then its time to pick what you want to light up. Choices include the house and its features such as rooflines, windows, doors, walkways and various other elements of the structure. Be aware that water is not friendly to lights so place them out of water runoff areas. Trees, bushes and other yard foliage is a good prop to light up as well. Some light elements you will have to create to achieve your idea of the perfect display. Light structures can be made in all sorts of shapes ranging from trees to trains and everything in between. You are only limited to the number of strings you can use! We started out by taking photos of our house and yard, then downloaded them into the computer. Using a drawing program, we sketched out where the light would be and after a number of times redrawing the plan, we came up with a good selection of locations to place the lights. Take time to consider all the possibilities and future expansion of your display. The sky is the limit (yes you might see it from space).

Electrical Considerations

Next, you will need a good supply of power. Mostly, this means good feed coming from an approved electrical panel box. Modifying panel boxes is best left up to licensed electricans instead of doing it yourself (that way you aren't in trouble). Not only will you need enough power to light your display but you will need the standard amount to properly run your home. Try not make your wife mad when you tell her to turn off the TV because you want to add another string of lights on the garage. Currently, we have a panel box in the house and also one in the garage. By sharing the load between the two boxes, we will have more than enough for the display and enough for upgrades for next year. Adding up all the light strings' amperage used when turned on, will give you the total amperage needed to distribute on the breakers in the panel box. For safety sake, try not to exceed 90% of the rated breaker load. Typical breakers for light circuits are 20 Amps. Thats enough for about 50 strings of lights (.33 amps per 100 count light string). Exceeding breaker ratings can be a bad thing and we don't want that at Christmas time. Also by using new LED type lights, you can increase the number of strings on a circuit. LED strings cost a bit more than incandesents but operating costs will be a lot lower in the long run.