I need some pointers on how to plan out the wiring for this project. I want to put strips on the house exterior, on the underside of the soffits, primarily for some pleasing downlighting on the facade. Maybe also for some holiday lighting.
It sounds like there are benefits in keeping these all on one output/data circuit, injecting power when needed. I have 3 potential injection points circled.
I sort of have this set up for three circuits of strips, but I can extend off the end of one run with a multipair (Cat 6, maybe?) to tie it to the start of another run. That first run on the left (over the left garage door) doesn't easily link back to the one over the 2-car side of the garage.
I don't know if it matters, but I have not decided on the hardware or even the software for this yet, since this is for a house under construction now. I am leaning towards Home Assistant.
I plan to have one or two security/automation/lighting panels in the garage, to house the lighting controller, power supplies, a network switch for the POE cameras, and some boards for access control devices and hardwired intrusion devices in this area of the home).
Injecting power when needed. I have 3 potential injection points circled.
Not nearly enough. At least at both ends and the middle, every meter would be good.
If it were me I'd probably use 12V or even 24V supply the put buck converters to 5V as physically close to the LED strips as possible to minimise the lengths of wire carrying high current.
larryd:
Strips in your front door area are a bit of overkill ;).
Perhaps, but I am thinking of using it instead of a porch light. it's not drawn out that way, but where it crosses in front of the door, I'd probably switch from the strips going on the underside of the soffit, facing down, to on the backside of that soffit, facing the door. I will mock this all up, lay it out in the driveway or yard, before mounting it. I may make use of the angled channel that is intended for wall-washing, to try to hit the walls with a down-lighting effect.
I think I have the "look" figured out, I just need to figure out the wiring. I've pondered it a lot. For example, that section lighting up the front door, I'd have door contacts trigger a scene to turn it off or dim it, so when you open the door to a visitor, they're not backlit and we're not blasted in the eyes with light.
PerryBebbington:
Not nearly enough. At least at both ends and the middle, every meter would be good.
If it were me I'd probably use 12V or even 24V supply the put buck converters to 5V as physically close to the LED strips as possible to minimise the lengths of wire carrying high current.
Yikes, really? Something I read already had me thinking 12V strips. I know that's not ideal for Arduino control, but I had also come across this post which makes me think I'm alright:
larryd:
Have you considered how the strips will be attached and maintained ?
BTW, you can use more than one Arduino.
They will be in aluminum channels with plastic diffusers (specific for the application), screwed to the soffit. while none of them will be without overhead cover, I will figure on preventative measures against water ingress (a little more research is needed here). I understand there are harness available to splice ends together, and I can solder extensions between them as needed. Shrinkwrap the splice or a gel splice or 3M Scotchlok suitable for the gauge (I figure 18AWG for power and data, although I can get Cat 6 for free at work so I was considering that for at least data, and doubling up pairs for power).
would certainly not be opposed to a couple Arduinos. I guess I was wondering how much that would complicate the coding, particularly if I get into holiday light effects. (our young kids love those, and one way I am 'selling' this to the wife is that and permanent Christmas lights).
By the way, I figure I need to do voltage-drop calculations on my cabling, and the strips, for power and data, so there are no surprises on start-up day. Does anyone have any pointers on that? Calculators are common enough online. It's been a while since I did this, but I need the power supply voltage, conductor or strip distance, load in amps, resistance per meter, type of conductor (copper, aluminium, etc.) and gauge. Right?
Yikes, really? Something I read already had me thinking 12V strips.
See Larry's reply #7, same idea, different method.
Yes, really. 12V strips will be less of a problem than 5V strips. I don't know the ideal spacing for power but definitely more than just one end. Get some strips, lay them on the floor and connect them up, see what happens.
12 V strips are not "a problem" for the Arduino as such. Incidentally, don't use UNOs, use Nanos - cheaper and more practical for "actual" installations. But note that the UNO/ Nano can only control about 300 LEDs or so in total.
The power supply is the big problem. 5 V strips at maximum power - and I am pretty sure you will want to use that - draw 5½ Amps per hundred and you need to tap that in at least every hundred (so that it supplies both forward and back from the tapping point, supply and ground of course) as the foil in the strips has limited capability.
There are two sorts of 12 V strips, one useful and one less so. The first has three actual LEDs in series as a group controlled by one chip; the series arrangement uses the 12 V supply efficiently but you only control a three LED group together.
The second type uses only one LED per control chip so that each LED is controlled individually, but uses just the same current as a 5 V strip so you are wasting the vast proportion of the power supplied. The only possible advantage of these strips is where a 12 V supply happens to be more convenient and they are at the expense of gross power wastage, tolerant of very large voltage drops in the wiring (though again, it would be quite inadvisable to expect the strip foil to carry more than a few Amps at any point).
Now the matter of data. It is most inappropriate to expect to transfer the data stream at any point more than a couple of metres at most. Also, as you must carry both data and ground together, you do not want the ground line accompanying the data to be carrying the LED power unless it is adequately rated - perhaps 2.5 mm2 cable. Given that, a practical approach might be to allocate a Nano or Pro Mini at one (input) end of each distant strip and use a serial interface chain of commands from one to the next. This would work at a modest serial rate and again, isolating the serial communication wiring from the power.
Another approach would be to use an ESP8266 to drive each separate chain. You need a 74HCT14 to level convert from the ESP's 3.3 V to the 5 V for the LED strip (5 V still for the 12 V LED strips) but using WiFi frees you from wiring interconnects. An ESP-01 with its adapter board or a WeMOS D1 Mini is very cheap and can control many hundreds of the LEDs - much more than the UNO/ Nano.
Paul__B:
12 V strips are not "a problem" for the Arduino as such..... but using WiFi frees you from wiring interconnects. An ESP-01 with its adapter board or a WeMOS D1 Mini is very cheap and can control many hundreds of the LEDs - much more than the UNO/ Nano.
Great information. I feel that my brain grew one size! I will plan on WiFi control and more power injection points. I can't expect these units to work reliably within the soffit under the various temp and humidity extremes, right? Placement within the garage is no issue, but I'll need to rough-in a box in my daughter's bed, to pick up that section.
I did this same exact thing at my house. You need to use 12v strips. With five volt strips you will need to inject power so often it will basically be impractical.
I injected inject power every 5 meters.
If you power the project from one centralized power supply, You should install 3 amp fuses for each injection location, since dc low voltage high current has a moderate fire risk.
My preference is to keep the lights all one one controller since that way animation is easier to sync. You still break it up into separate zones later on by creating indexes on led locations in an array corresponding to the zones.
I would route the data wiring from the right to left on the upper row, the hop back to the lower eve up back to the upper eve.
You need to run the data and ground together as a twisted pair. Keep the wiring as short as possible. I think you will get away with the run in between the two strips on the left side, but if that doesn’t work you can use Rs232 chips to convert the data into that protocol which is better at transmitting the data over that distance.
If you haven’t built the house yet, I would look at installing aluminum Channel in the eve.
Qdeathstar:
If you haven’t built the house yet, I would look at installing aluminum Channel in the eve.
In the eve or on the eve? I was figuring on channel on the underside of the soffit/eve, but I can certainly get in there before the metal framing goes up and pre-wire for power & data, drilling through the wood cross-members.
My limited research has me thinking I've narrowed it down to the WS2815, at least until they come out with a 12 volt SK6812, with its dedicated white channel (I'll be running these in white generally).
I like the WS2815's backup data channel (might save me headaches and ladder time later), and while energy efficiency is not the best, at least I can get power supplies for almost nothing through my employer (I am in the commercial building security system business).
Paul__B:
Presumably you used the more efficient ones with LEDs controlled in groups of three?
Which would have been more than adequate for a display viewed at a distance,
I think I'd rather not limit myself in resolution, in case I later want to do some fancier effects, but admittedly this is primarily house facade downlighting and some front area lighting, not intended to be an award-winning Christmas light display.
I've just come back from the drawing board. Here is what I've come up with for controllers (3) and (2) additional power injection points:
I can't expect these units to work reliably within the soffit under the various temp and humidity extremes, right?
I don't see a problem if they are enclosed. I would use metal boxes and make sure there are small ventilation holes in the bottom to let water out. Make sure they are accessible for repair / replacement if needed. You are, after all, putting 100s of LEDs under the soffit.
airwreck:
In the eve or on the eve? I was figuring on channel on the underside of the soffit/eve, but I can certainly get in there before the metal framing goes up and pre-wire for power & data, drilling through the wood cross-members.
My limited research has me thinking I've narrowed it down to the WS2815, at least until they come out with a 12 volt SK6812, with its dedicated white channel (I'll be running these in white generally).
I like the WS2815's backup data channel (might save me headaches and ladder time later), and while energy efficiency is not the best, at least I can get power supplies for almost nothing through my employer (I am in the commercial building security system business).
I would use ws2811 12v strips. The chips are pretty robust and not likely to fail. I have and my strips up for about. two years. I think you should hit up aliexpress and search for aluminum led channel and pick an extrusion you like. You need to know the width of the strip you are using and verify it fits in the extrusion, obviously.
airwreck:
I think I'd rather not limit myself in resolution, in case I later want to do some fancier effects, but admittedly this is primarily house facade downlighting and some front area lighting, not intended to be an award-winning Christmas light display.
I've just come back from the drawing board. Here is what I've come up with for controllers (3) and (2) additional power injection points:
The power in inject points, you need them at least every 16 feet. (for 60 leds/meter 12v strips) If you go with 5v strips they need to have power added every 3-5 feet, depending on how many leds they are.
And they need to be fused at the power supply location. Data should start at one end of the strip. with the controller close to the strip, and ran in such away as to limit the length of wire runs between the strip. When you run a data cable run ground with it, in a twisted pair.
