The Helix is one of the most advanced DIY light controllers available. It is a standalone, networkable, distributed light controller that can control a virtually unlimited number of channels. The sequences are created using Vixen. A full Helix system consists of one Main board, three Daughter boards and 32 four channel random-phase turn-on Solid State Relay (SSR) boards for a total of 128 light channels. There is an optional 32ch SSR Daughter board (essentially a Daughter board with integrated SSRs) that can replace one or more of the regular Daughter boards. Each channel has 256 levels of dimming for maximum control of your display.
The main thing that sets the Helix apart is its ability to operate as a standalone controller. With the Helix you can store the sequences, MP3 songs and a show schedule onto a microSD card. This microSD card plugs into a socket on the main board. The Helix will read the show schedule off of the card and at the correct time start displaying the show. The songs are played on a MP3 player that plugs into the main board. The output of this MP3 player can be connected to a small FM radio transmitter so everyone can enjoy your show from the comfort of their vehicle. The show repeats until the scheduled shut down time. All of this automatically happens every day until it is time to take the display down.
What if You Need More Than 128 Channels?
This is where the real power of the Helix comes into play. Each Helix main board is equipped with a Digi (formerly MaxStream) XBee-Pro RF module. The XBee-Pro is a low cost, low power radio transceiver with a very good range (approximately 1 mile line of sight). This radio is used to wirelessly network two or more Helix systems together. This allows a virtually unlimited number of channels(1) to be synchronized together and with a range of about 1 mile it should be possible to synchronize the lights on every house on a city block!(2)
Note 1: The current protocol limits the number of channels to 32,256; however, if more channels are needed the protocol can easily be expanded to support over 8,000,000 channels. (I can't even conceive of trying to sequence 32,000 channels let alone 8,000,000. So as far as I'm concerned the current protocol is virtually unlimited.)
Note 2: This is theoretically possible but has not been tested yet. gmbartlett will provide all of the technical assistance necessary to the first person that wants to give this a try.
The Helix system is fairly complex to build and operate. It requires hand soldering of surface mount components. It requires an understanding of the limitations of the XBee wireless radio protocols and an understanding of the Helix Network. It also requires multiple extra steps to get from a sequence created with Vixen to a working show on the Helix. To minimize this complexity the hardware and firmware are configuration controlled by the designer, Gregory Bartlett (aka gmbartlett). Any suggestions for upgrades or changes should be addressed to him. To further minimize the complexity, the Helix Main boards are provided with the surface mount microSD card socket presoldered. They also come with a preprogrammed EEPROM.
The following terms with their associated definitions will be used throughout the rest of this Wiki and should be used in the forum discussions.
Helix Main Board
This is the “brains” of each Helix System. The main board consists of a power supply, AC Zero crossing circuit, Parallax Propeller processor, EEPROM, XBee radio and three channel bank ports (each a triple RS422/485 driver). If the Main board is also the Helix Network Controller (HNC) it has a MP3 player and Real Time Clock (RTC). All Main boards have a microSD card socket where the firmware, system configuration file, sequence data for its system and, in the case of the HNC, the MP3 songs and schedule are stored. The Main board can directly control 32 channels using the standard four channel random-phase turn-on SSR boards. The SSR boards are connected to the Main board via a standard Cat5 cable. Each of the channel banks can control one of the Helix Daughter boards.
Currently there are two versions of the Helix Main board. Both boards are virtually identical and are interoperable. The main differences between the versions are:
1) The V2 board has a couple of test points that make assembly and troubleshooting easier.
2) The V2 board has a horizontal fuse holder as opposed to the vertical fuse holder on the V1 board.
3) The V2 board has a XBee TX LED that shows when the Propeller chip is transmitting to the XBee
4) The V2 board has the MP3 player powered by 5VDC as opposed to 3.3VDC on the V1 board.
5) The V1 board had three surface mount quad RS422 drivers and the V2 board has three through-hole quad RS485/422 drivers.
6) The V2 board is 1/2" taller than the V1 board.
7) The V2 board has a port for an external trigger that can be used to start a show. (This feature exists in hardware but hasn’t been implemented in the firmware yet)
8) The V2 board has a port that can be used to drive a MiniRDS board. (This feature exists in hardware but hasn’t been implemented in the firmware yet)
The Helix Main board easily fits in a CG-1500 enclosure.
Helix Daughter Board
This board is little more than a channel driver, there is no intelligence on this board. It is connected to the Helix Main board via a standard Cat5 cable. It receives its signals via the triple RS485/422 drivers on the Main board. The Daughter board can directly control 32 channels using the standard four channel random-phase turn-on SSR boards. The SSR boards are connected to the Daughter board via a standard Cat5 cable. It requires an external 5VDC power supply. It easily fits in a CG-1000 enclosure.
Helix 32ch SSR Daughter Board
This is a standard Helix Daughter board with 32 SSRs integrated on the board. There are four banks of eight random-phase turn on SSRs. Each bank of eight SSRs can be independently powered via a 15A, 120VAC input giving you the ability to switch up to 60A. Each channel should be limited to a max of about 1.75A (with appropriate heat sinks of course). Alternatively all four of the SSR banks can be jumpered together and powered from a single AC input. Any combination between one and four AC inputs can be used. This board will easily fit in a CG-1500 enclosure.
One Helix Main board, up to three Daughter boards and the associated SSR boards
Two or more Helix Systems wirelessly linked together using the XBee radios
Helix Network Controller
This is the first Helix System in a Helix Network. It is responsible for starting and stopping the show, playing the MP3s and providing a sync message to all of the other Helix Systems in the network.
Helix Network Node
This is a Helix System that is part of a Helix Network and is not the Helix Network Controller. It is only responsible for controlling its channels under the timing of the Helix Network Controller.
This is a music and light performance, created with Vixen that has the lights synchronized with music. The music is divided into discrete time slots called events. The time between events is called the event period. A typical event period is 50ms or 20 time slots per second. The lights are divided into different channels. Each channel is an element of your overall display. The state of each light channel can be changed at each event. The collection of all of the state changes for every event is the sequence.
This is an ordered list of sequences and pauses between sequences that are played on the Helix. There can be up to 99 sequences and pauses in a Helix Show.
This is an ordered list of MP3 songs that the Helix plays between Helix Shows. There can be up to 99 songs in a Helix Playlist.
This is an ordered list of Helix Shows and Helix Playlists with associated start and stop times. There can be up to a total of 9 Helix Shows and Playlists for each day of the week. The one major limitation at this time is that the Helix Show or Playlist must start and stop in the same day.
Helix Network Supervisor
This is a Microsoft Windows application that is used for several aspects of managing the Helix System. Its primary functions are to convert the Sequences created by Vixen to a format that the Helix can use and create the Helix Shows, Helix Playlists and Helix Schedules. It is also used to set the time on the RTC, run test routines, start/stop a Helix Show and check the status of a Helix Network. The Helix Network Supervisor requires a XBee radio and XBee USB carrier board to perform the setup and testing functions.