Arduino GE G-35 Multi-String Controller Code

**firstone** · 10-04-2011, 01:50 PM

I've written some arduino code that can control multiple GE G-35 strings at once. It can control 8 at the same time (provided they're all on the same port). It takes around 920 usec to update 1-8 lights. So it could update 400 lights at the frequency 21 Hz (if my calculations are correct). Of course, if you need to use multiple ports, the frequency decreases exponentially. Although, normally, you do the updates to multiple ports simultaneously, rather than update all 50 lights on one port and then update the next port.

The first is a common library:

GECEWriter

It should go into your <Arduino Projects Dir>/libraries directory. And it contains code to actually send signals. As well as some code for parallelizing updates. You basically specify the program to run for a particular string of lights (track) and the framework will execute it in parallel.

The second is an example program with some simple animations:

GECELights

This uses the above library and executes some programs on the attached strings of lights.

Finally, there is a en ethernet UDP controller:

GECERemote

This code listens to UDP messages in my custom format (number of commands byes (1 <= X <= 8), followed by 5 * X bytes commands, each of which is pin (track) number, followed by 4 bytes (32 bits) light command. 26 lower bits out of 32 are used and are the same as GE control protocol 26 bits.

Because this involves a UDP read, it lowers update rate. Safe margin is 1.2ms per port, which brings refresh rate down to 16 Hz. There is not much I can do about UDP read delay, of course, but I can potentially change it to read multiple ports update in one message. So for instance, updates to 3 ports will take 3ms rather than 3.6ms.

I also have Java based controller that I'm planning to use to send commands to the above program (GECERemote). I haven't put it into git yet but if there's interest, I will do it.

I'd appreciate some opinions, comments, etc. Thanks.

**ukewarrior** · 10-04-2011, 05:25 PM

This is great, I can use this with indoor lights !

What version of arduino did you build this on?

**Materdaddy** · 10-04-2011, 05:35 PM

Another question... How are you guys hooking up your light strings?

I have a few sets and have done some tinkering w/ my arduino uno, but haven't had enough time to do much. I'm still trying to figure out the best way for me to get everything going outside.

**Livermore-Dad** · 10-04-2011, 05:44 PM

Pretty cool, ya had my stings working with the arduino last year (basic instructions), but I like that you have taken it further.

Although I'll use the pixel controller this year, I do have other ideas that the arduino/code would be good for (outside landscape lighting)

**firstone** · 10-04-2011, 10:51 PM

I've built it using Uno but it should work with Mega too.

As far as hooking it up, if you're referring to running power and such, I haven't finalized it myself yet. Since it's for my own house rather than some commercial installation, I'm tempted to just run power through one long wire and keep power supply and arduino indoor. I've done some testes with running power through 100' of 14/2 landscape wire and running data through 80' of CAT5 and it seemed to work in my test environment. So I figured I'll try it and if I have any issues, I'll change the power supply to 12v and add voltage converter.

As far as physically connecting the strings, I've ordered 4 core waterproof plugs from Ray Wu and will use those to have removable connections. Got 4 core in case I need to switch to RS-485.

Originally Posted by Materdaddy

Another question... How are you guys hooking up your light strings?

I have a few sets and have done some tinkering w/ my arduino uno, but haven't had enough time to do much. I'm still trying to figure out the best way for me to get everything going outside.

**Materdaddy** · 10-04-2011, 11:08 PM

Originally Posted by firstone

I've built it using Uno but it should work with Mega too.

As far as hooking it up, if you're referring to running power and such, I haven't finalized it myself yet. Since it's for my own house rather than some commercial installation, I'm tempted to just run power through one long wire and keep power supply and arduino indoor. I've done some testes with running power through 100' of 14/2 landscape wire and running data through 80' of CAT5 and it seemed to work in my test environment. So I figured I'll try it and if I have any issues, I'll change the power supply to 12v and add voltage converter.

As far as physically connecting the strings, I've ordered 4 core waterproof plugs from Ray Wu and will use those to have removable connections. Got 4 core in case I need to switch to RS-485.

These?
http://www.aliexpress.com/fm-store/7...nd-female.html

I ordered a few sets of those a few days ago as well. I ordered 4-core not just because I might switch to RS-485, although that's a good reason. I ordered 4-core because they're slightly cheaper than the 3-core ones I previously found.

I am hoping that I can somehow "waterproof" (heat shrink/hot glue/etc.) the connections to my strings, but if you get yours figured out, I'd love to see pictures.

Thanks for the reply!

**firstone** · 10-04-2011, 11:29 PM

Yeah, those are the ones I got. His 3 core are actually a bit cheaper but no big deal.

I haven't actually used them yet but but I'm planing to use heat shrink. I figured one tube per wire and larger one on top should do the job. I don't know when I'm going to get it done but I will certainly post a picture when I'm done.

**Braveit1** · 10-07-2011, 09:46 AM

Great work. I have a few sets I picked up after last year but havn't done anything with them at all. They're still in the boxes. Not enough time....

**firstone** · 10-10-2011, 12:00 AM

A little update on my project. The good news is that the basic functionality is very stable. You can easily write updates to multiple stings of lights in a single write (up to 8 max). In fact, you can just take 3 classes from my project and write commands.

Now for the bad news. The final stage of my project was to add E1.31 and control Arduino by some sequencer. Kinda to have E680 equivalent on Arduino. Well, I've finally finished the code and have it working but the project has failed miserably. Arduino is just way too slow for it. Unfortunately, the slowest part is a network read. I've estimated it to be around 12 usec per character (+ 190 usec overhead). So even a short E1.31 message at 172 bytes takes over 2000 usec to read. Add 900 usec writing delay and it takes a whooping 3000 usec, or 3ms. Way too slow. If anyone is interested, I can make E1.31 code available but it's really not useable. Perhaps when Arduino Due comes out, it might bring things back into useable territory.

The second problem I've found is that GE lights seems to be very sensitive to the voltage. I've tried to control them with a different power supply, which gets max of 5.42v and it doesn't work. Apparently, it really does require around 5.6v. So I guess I'm just going to give up on a unified power supply and just use the supplied ones and run power extension cords to the roof. The alternative would be to use 12v and step down to 5.6v but that would require a variable voltage converter and it's probably more work than I want to invest into it at this point.

**dmcole** · 10-10-2011, 05:15 PM

Originally Posted by firstone

Arduino is just way too slow for it.

Yeah, I thought this might be the outcome ...

I actually wrote a post suggesting the A would be too slow and then threw it away, because I thought I might be wrong (so often I am).

The 16 MHz oscillator just doesn't give you much elbow room to do anything complex. You could up the speed of the crystal, but then it wouldn't run the Arduino IDE and then you may as well be using C++ and AVRDude.

Thanks from those of us in the peanut gallery who were cheering you on.

\dmc