Dream Chip LEDs with Arduino

[giulianom]

I thought it was about time to split off my DIY of the http://www.atlantareefclub.org/forums/showthread.php?t=76590">Dream Chip LED</a> build into a separate thread so as not to clutter up Hanin's [IMG]http://www.atlantareefclub.org/forums/showthread.php?t=77295">Dream Chip Build Thread.</a>


[IMG]http://www.atlantareefclub.org/forums/showpost.php?p=844546&postcount=6"> <span style="font-size: 14px;"><span style="color: Red;">Parts List is Here</span></span></a>



Here is what I have planned:


<ul>
<li>3 x 100-chip Dream LEDs, 252 Watts max each, but running at 180W each - 480W total vs 756 Watts.

Each channel can handle 1400mA (1.4A) of current at it\'s maximum level, but I have chosen to use drivers that provide 1000mA (1A) of current instead, to reduce heat and power consumption, as well as increase the lifespan of the LEDs. Running LEDs at 100% capacity is not necessarily good over a long period of time.</li>
<li>120mm fan Heat Pipe GPU coolers for the LEDs.</li>
<li>3D-Printed custom enclosure for the LED and Heatsink, with either a borosilicate glass cover plate or a large optical lens. The enclosure will have a [IMG]http://en.wikipedia.org/wiki/Gimbal">gimbal </a>style mounting bracket(s) so that the LED can be angled manually - or possibly driven by servos? Imagine LEDs that tilt and rotate to simulate the sun/moon patterns...</li>
<li>The Dream Chip LEDs each have 5 channels of LEDs in these different spectrum:
[LIST]</li>
<li>Channel 1) 10S x 2P 10000K (EPISTAR: 45mils)</li>
<li>Channel 2) 10S x 2P 455nm (EPISTAR: 45mils) (blue, beneficial to chlorophyll C)</li>
<li>Channel 3) 10S x 420nm parallel with 10S x 430nm (EPILED: 45mils) (UV range)</li>
<li>Channel 4) 10S x 2P 445nm (EPISTAR: 45mils) (blue, beneficial to chlorophyll C)</li>
<li>Channel 5) 10S x 2P 15000K (EPISTAR: 45mils)</li>
</ul>

[/list]

<ul>
<li>Each channel will be driven separately using a [IMG]http://www.meanwell.com/search/LDD-H/LDD-H-spec.pdf">Meanwell LDD-1000H</a> driver chip, providing up to 1000mA (1A) max per channel. These driver chips are very nice for this purpose (and other LEDs!) because:
[LIST]</li>
<li>They take a wide range of DC input voltage, anywhere from 9V to 56V, and automatically step-down as required. In my case, I\'m powering ALL the LEDs from a single 48V AC-DC power supply that can handle 480 Watts.</li>
<li>They can take a PWM signal for dimming, and can dim all the way down to 0% - completely off. The PWM signal can also be run at a frequency of up to 1000Hz (1kHz), making the resulting dimming at low levels ultra ultra smooth. Incandescent lights flicker at 60 Hz, and most people won\'t see a flicker at 120 Hz... at 1000 Hz - it\'s pure awesome. Most other drivers have a lower limit cut-off at 10%, otherwise you\'ll see the flickering of the LED\'s turning off and on at low levels.</li>
<li>With 15 channels, that means 15 driver chips - they\'re $5-10 each, and very small. I have a circuit board set that is being made that holds 5 LDD drivers on a diagonal board 10cm square (~4\" square).</li>
</ul>

[*]The LEDs will be controlled with a custom Arduino microcontroller package:
<ul>
<li>Based on the newest [IMG]http://arduino.cc/en/Main/ArduinoBoardDue">Arduino Due</a> board, I\'ll be running a cloned model called the [IMG]http://www.ebay.com/itm/TAIJIUINO-Due-Pro-Board-with-Programmer-completely-compatible-with-Arduino-Due-/140903497573?pt=LH_DefaultDomain_0&hash=item20ce80bf65">Taijiuno Due Pro</a> from China.</li>
<li>The LDD drivers will be driven by a PWM signal generated by this 16-channel PWM/Servo board, the [IMG]http://www.adafruit.com/products/815">Adafruit 16-Channel 12-bit PWM/Servo Driver</a>. These boards are particularly nice because they can run independently of the Arduino board - once you set a PWM signal, it runs continuously until you need to change the level. This frees up the Arduino to do other tasks while the PWM board handles driving the LDD drivers. They can also be daisy chained together if you need more PWM ports.</li>
<li>Someone on another forum designed a circuit board to hold 5 x LDD drivers, so I ordered 10 boards from a PCB fabrication company for about $35 for 10.</li>
<li>The Arduino package will also have:
[LIST]</li>
<li>A [IMG]http://www.ebay.com/itm/111008432389">7\" Touchscreen LCD</a> display, also with an [IMG]http://www.ebay.com/itm/121057447668">Adapter Shield</a>.</li>
<li>An [IMG]http://www.ebay.com/itm/260868624339">Ethernet Port</a> for remote control (eventually!).</li>
</ul>

[*]The whole enclosure and LEDs will be powered by a single [IMG]http://www.ebay.com/itm/380556652740">48V 480W AC-DC Power Supply</a>.
[*]The Arduino board and accessories will be powered by this [IMG]http://www.ebay.com/itm/290863793506">48V to 12V and 5V converter</a>.
[*]Each LED module will have two cables going to it:
<ul>
<li>A [IMG]http://www.molexkits.com/76650-0078">10-pin Molex</a> connector for the 5x LED power and ground lines.</li>
<li>An [IMG]http://www.ebay.com/itm/120968046027">8-Pin RJ45 Ethernet port</a> for power to the 120mm fan and digital [IMG]https://www.sparkfun.com/products/245">Temperature Sensor</a>. The ports use an Ethernet cable to transmit 12V and Ground for the fan, PWM for the fan speed control, tachometer signal from the fan, 5v and Data for the Temperature Sensor.</li>
</ul>

[*]All of the above will be assembled in a 3D Printed custom enclosure, most likely as an all-in-one box with the LCD display on the front/top.
[/list]

[/list]


So, there you have it!


At this point, I'm at the stage of ordering the hardware parts.


Most of the stuff from eBay comes from China, and should be here in a few weeks.


The 15x LDD-1000H drivers I ordered from PowerGate LLC are back ordered (they're popular!) but should be here by April...




Once I get most of the hardware parts, I'll be working on designing cases and enclosures and then 3D Printing them.



Following getting the hardware running, the tough part comes next - writing the code!


Thankfully, there are a few examples out there of people that have built Arduino-based Aquarium Controller code packages, so I may use some of those as a starting point.

 

[giulianom]

First parts have arrived...

Not much, just the 10-pin molex connectors for the LED wiring, and a 24" 40-pin/wire IDE extension ribbon cable.


The connector has to have 10 pins because each LED has to have a separate ground wire - you can't share the ground lines between LEDs and their driver chips.

These are relatively small - only about an inch wide by 1/2" thick.

The female end is meant to be panel-mounted, it has plastic clips that let it be held in a hole cut to size in a flat panel - such as a piece of aluminum sheet, or the plastic walls of the box I'm going to 3D print.




The LCD panel uses a 40-pin header, with a male connector on one end and female on the other, so the extension cable will connect the two.

I hope to be able to place the LCD panel a little bit away from the electronics box, so hopefully 24" isn't too long and the electrical signals won't get out of whack.

The LCD uses parallel wires to receive its data from the Arduino board, so there is a limit as to how far you can make a cable before the signal degrades.

alt="" /></a>

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[sewer urchin]

Not much, just the 10-pin molex connectors for the LED wiring, and a 24" 40-pin/wire IDE extension ribbon cable.

All great things have to start somewhere!

Following along...I seem to pick up a lot of info reading your threads ;-)

 

[giulianom]

Sewer Urchin;843374 wrote: All great things have to start somewhere!

Following along...I seem to pick up a lot of info reading your threads ;-)

Thanks..


I read online that people had no problems with a 12" cable, so hopefully the 24" cable should be ok.

If all goes well, I'll slice up the ribbon cable and sleeve it like this:

http://www.techpowerup.com/forums/showthread.php?t=81477">http://www.techpowerup.com/forums/showthread.php?t=81477</a>


The plan is to have the electronics box with the Arduino mounted on the inside of my canopy, with the LCD Panel mounted on top, or on the inside of one of the door panels for easy access.

 

[giulianom]

Third part arrived - a 17-48V to 12V/5V power converter.


This will take the 48V power supply output and drop it down to 12V for the Arduino board, as well as provide a 5V power source for other things.

It's capable of providing 1.5A of current, which should be enough for the Arduino board, which has its own power regulators.


It's pretty small, about 2" square.

alt="" /></a>

 

[giulianom]

I received a request for a parts list on this build, so I'm going to list them all out here for reference.

I'll edit the list as it develops.


<span style="font-size: 14px">Parts List</span>

<ul>
<li>3 x http://www.atlantareefclub.org/forums/showthread.php?t=76590">Dream Chip LEDs</a> from eBay seller AC-RC. [B]Cost: $180[/B] [B]each[/B], [B]not generally available.[/B]
These were available as left-overs from someone else's previous group buy, and I was only able to get 3 of them.</li>
</ul>
[INDENT]To get more would require a fairly large group buy, as they're produced only in batches of 50 or so. The individual cost in a group buy would most likely be more than what these three cost me.[/INDENT]
<ul>
<li>3 x [IMG]http://www.ebay.com/itm/220W-Multichip-LED-Cooler-/271051176895">220-Watt MultiChip LED Cooler</a>, also from AC-RC. [B]Cost: $83 with shipping.[/B]</li>
</ul>
[INDENT]These are heat pipe coolers originally intended to cool graphics cards in PC's, but these come with a bonus aluminum plate adapter to mount the LEDs.[/INDENT]
<ul>
<li>15 x [IMG]http://www.meanwell.com/search/LDD-H/LDD-H-spec.pdf">MeanWell LDD-1000H LED Drivers</a>, from [IMG]http://www.powergatellc.com/mean-well-ldd-1000h-dc-dc-converter.html">PowerGate LLC</a>. [B]Cost: $4.37 Each, for 15.
Currently back ordered through April.[/B]

These are small DC-DC LED drivers that provide up to 1000mA (1 Amp) of current, and are dimmable with a PWM signal only (no 1-10V or potentiometers). They accept a wide range of DC input voltage, and only require that the input voltage be 3V higher than the output voltage. They can also dim all the way down to 0-1%, and can turn the LEDs off entirely.

Other versions are available for 300mA, 350mA, 500mA, 600mA, and 700mA in addition to the 1000mA maximum.</li>
</ul>

<ul>
<li>An [IMG]http://arduino.cc/en/Main/ArduinoBoardDue">Arduino Due</a> clone board, the [IMG]http://www.elechouse.com/elechouse/index.php?main_page=product_info&cPath=72_73&products_id=2214">Elechouse Taijiuino Due Pro</a> - bought from eBay. [B]Cost: ~$50[/B]</li>
</ul>
[INDENT]This version is different from the standard Ardiuno Due board in that it has a few more input/output pins available, and it has special pins made available for enabling on-board Ethernet for network communications.[/INDENT]
<ul>
<li>A [IMG]http://www.ebay.com/itm/111008432389">7" touchscreen LCD display</a>, an [IMG]http://www.ebay.com/itm/121057447668">adapter "shield" board</a>, and a [IMG]http://www.ebay.com/itm/280622677940">24" Ribbon Cable</a> to connect it all to the Arduino board. These will serve as the main control interface for the LEDs. [B]Cost: $60, $10, and $8 ($78 total).

[/B]</li>
<li>An [IMG]http://www.ebay.com/itm/260868624339">Ethernet transceiver</a> module - this allows me to wire this module up to the Arduino board's native on-board Ethernet pins for network communications - eventually. [B]Cost: $10[/B]</li>
</ul>

 

[giulianom]

The Adafruit 16-channel PWM driver board is back in stock:

http://www.adafruit.com/products/815">http://www.adafruit.com/products/815</a>


I ordered two boards - one board will use 15 out of 16 channels to provide the PWM dimming signal to the MeanWell LDD drivers.

I will probably use the second board to control speed of the 3 fans on the LED heatsinks...


So out of a total of 32 PWM channels, I'll use 14 right out of the box.

I may have a use for some of the others...

 

[giulianom]

My Arduino clone board arrived!


The board - you can see the pin holes for the Ethernet interface - I'll have to get a very small pin header and do some tiny soldering..

alt="" /></a>

alt="" /></a>


Here's the programmer board - I hook this up to the Arduino board to program it, connected to the computer via USB.

alt="" /></a>


Here's the Ethernet interface board - the larger pins on the end connect to the smaller pins on the Arduino board - though I'll probably have to get/make an adapter cable.

alt="" /></a>

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[giulianom]

The 10-pack of 5 x MeanWell LDD driver PCBs have arrived!

The lettering is a bit off, but otherwise it's good.


Also, while you can see the ++ positive lines for the power input, you don't see the -- negative lines for the input - that's because the 3 pairs of pin holes next to the ++ inputs are ground plane connections.


I'll have to get some screw terminals that I can solder to the board for the wires, and then it's just waiting for the actual LDD driver chips... in April.

The screw terminals are here:

http://www.mouser.com/Search/ProductDetail.aspx?R=1705621virtualkey65100000virtualkey651-1705621">http://www.mouser.com/Search/ProductDetail.aspx?R=1705621virtualkey65100000virtualkey651-1705621</a>

Turns out that they're more expensive than the PCB itself.. :)


Also turns out, there was a later revision of this board design that used less expensive connectors... oh well.


[IMG]http://imgur.com/GTpc9f8">[IMG]http://i.imgur.com/GTpc9f8l.jpg alt="" /></a>

alt="" /></a>

 

[jbadd99]

I'm considering copying your Arduino controller and I have a few questions...

First - why the knockoff Due?
Second - where is the RTC? Or is that a later addition?

Why not buy a preassembled ethernet port, or for that matter, a WiFi enabled board.

As I understand it, with the adafruit drivers, you'll be able to control as many PWM channels as you'd like, as opposed to the 12 signals limited by the controller - this means as many PWM dimming LED channels as you'd like, or multiple fans, etc, correct?

Also, where did you get your PCBs printed? I'd like to do some PCBs, but I'm using 3W LEDs that drive at 500-700mA, so I'm thinking about going with the LDD-500H or the 700H, which I understand is smaller so I'd likely need a smaller PCB printout, which I can't seem to find

Or, since I'd be using the Adafruit boards, which are adjustable, could I just stick with the 1000H and use the Adafruit board to adjust to different mA?


I'm following a http://www.reefcentral.com/forums/showthread.php?t=2222702">THREAD</a> on ReefCentral that is doing a fairly good job of explaining things, but it's a legthy read that you have to sort through.

Not criticizing your project, just trying to understand your choices and trying to assemble something similar.

 

[giulianom]

Good questions!

I'll answer in line..

jbadd99;848784 wrote: I'm considering copying your Arduino controller and I have a few questions...

First - why the knockoff Due?
Second - where is the RTC? Or is that a later addition?

Why not buy a preassembled ethernet port, or for that matter, a WiFi enabled board.

The processor chip on the Due has dedicated Ethernet pins on the chip, but they're not exposed on the official Due board itself.

The clone Due board does have the pins routed out to a pin header, so all you need to use the native Ethernet is a $10 Ethernet PHY interface, and some wires to connect it to the pin header.

Although on my clone Due board, the Ethernet interface pins don't have headers soldered on, so I'll have to do some careful soldering of some 1.27mm-pitch (0.050") pin headers - which conveniently arrived today.


The RTC board will be added on later - the Due boards are only 3.3v compatible, so most 5v boards won't work.

Also, the cost of the "Official" Due and the clone Due were the same - $50.

jbadd99;848784 wrote:
As I understand it, with the adafruit drivers, you'll be able to control as many PWM channels as you'd like, as opposed to the 12 signals limited by the controller - this means as many PWM dimming LED channels as you'd like, or multiple fans, etc, correct?

More or less, yes - each Adafruit PWM board can provide 16 PWM channels, and they're daisy-chainable to something like 62 boards.. a massive number of outputs.

Also, these Adafruit PWM boards have a few advantages over the on-board PWM or other PWM-driver boards:

<ul>
<li>They are 12-bit (4096 steps) instead of 8-bit (256 steps) - the more steps you have, the finer the resolution you have - and smoother dimming. Imagine it as having 40 steps per percent of dimming vs 25 steps per percent of dimming.</li>
<li>They have their own clock generator, so once you issue them a command to output a PWM signal, they continue to do so until you change it - independant of what the Arduino is doing at that moment. Also, I believe it means each port can run at a different frequency.</li>
<li>They can provide an output current (current source) or receive an input current (current sink). The TLC5940 PWM driver board can only receive a current, which makes the dimming cycle inverted... 4095 would be 0%, and 0 would be 100%... not ideal.</li>
<li>The frequency is variable from about 40-1000hz, which matches the frequency range of the MeanWell LDD drivers... About 1000Hz (1kHz) is 1000 times per second, and since the output of the LDD driver matches the input PWM signal, the more times it switches per second, the smoother it'll look at low levels.</li>
</ul>

jbadd99;848784 wrote:
Also, where did you get your PCBs printed? I'd like to do some PCBs, but I'm using 3W LEDs that drive at 500-700mA, so I'm thinking about going with the LDD-500H or the 700H, which I understand is smaller so I'd likely need a smaller PCB printout, which I can't seem to find

I used ITead Studio: http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html">http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html</a>

I chose the 10 x 10mm x 10mm board option, which cost around $35 in total for 10 boards including shipping.

I placed an order, uploaded the Eagle schematic files that someone else had designed and in a few weeks I had 10 nice and shiny boards...


The boards I got fit the MeanWell LDD-H series - LDD-1000H, LDD-350H, LDD-700H, etc..

The number indicates the current output - 1000mA (1A), 350mA, 700mA, etc..

[QUOTE=][B]jbadd99;848784 wrote:[/B]
Or, since I'd be using the Adafruit boards, which are adjustable, could I just stick with the 1000H and use the Adafruit board to adjust to different mA?
[/QUOTE]

No, the Adafruit boards only provide the PWM signal to control the LDD dimming.

You'd want to get a LDD driver to match the amount of current you'd need for that string of LEDs - 350mA, 500mA, 700mA, etc..

The specs are here: [IMG]http://www.meanwell.com/search/LDD-H/LDD-H-spec.pdf">http://www.meanwell.com/search/LDD-H/LDD-H-spec.pdf</a>

Pick one with a Current Range close to, but preferably not more than, what the LEDs can handle at max power.


In the case of these Dream LEDs, each string can handle a max of 1400mA - but since the LDD drivers only go up to 1000 mA, that's as high as I can take it.

Which in reality is not such a bad thing, less power, less heat... more lifespan on the LED chips.

[QUOTE=][B]jbadd99;848784 wrote:[/B]
I'm following a [IMG]http://www.reefcentral.com/forums/showthread.php?t=2222702">THREAD</a> on ReefCentral that is doing a fairly good job of explaining things, but it's a legthy read that you have to sort through.

Not criticizing your project, just trying to understand your choices and trying to assemble something similar.[/QUOTE]

Yeah, I think that's the thread where I found the 5x LDD driver PCB design...

Look for a guy named "O2Surplus" - he designed the boards I had made, but I believe later on he came out with a revised version that uses less expensive wiring connectors.

I used the first revision, which requires more pricy $7 connectors - two per board - but still not bad in all.

 

[jbadd99]

Now the question that's been burning in the back of my mind... Where are you going to get your enclosures made?

 

[giulianom]

jbadd99;848906 wrote: Now the question that's been burning in the back of my mind... Where are you going to get your enclosures made?

You mean, when am I going to print them?

It will be in two pieces - a box of electronics about 200x100x100mm or so with a lid, and a case for the LCD panel.

I have all the parts for the first box to be designed, but the LCD was delayed... Hong Kong Post apparently misplaced the package, but its on the way...


I continue to have to work on calibration issues with my 3D printer to get the bed flat...

But I expect to be able to get some real design work done soon.

 

[jbadd99]

GiulianoM;848914 wrote: You mean, when am I going to print them?

It will be in two pieces - a box of electronics about 200x100x100mm or so with a lid, and a case for the LCD panel.

I have all the parts for the first box to be designed, but the LCD was delayed... Hong Kong Post apparently misplaced the package, but its on the way...


I continue to have to work on calibration issues with my 3D printer to get the bed flat...

But I expect to be able to get some real design work done soon.

Not fair.

How much to print one for me?

 

[giulianom]

Probably not so much, I can get an entire spool of plastic filament for $40, and that's a fair amount of plastic.

The rest is just design effort and letting the printer run for several hours, once I get it tuned right...

 

[jbadd99]

GiulianoM;848821 wrote: The processor chip on the Due has dedicated Ethernet pins on the chip, but they're not exposed on the official Due board itself.

The clone Due board does have the pins routed out to a pin header, so all you need to use the native Ethernet is a $10 Ethernet PHY interface, and some wires to connect it to the pin header.

I bought an Arduino Mega 2560 board a while back, but I haven't done anything with it. I was debating about using it, but it looks like you need a seperate RJ45 shield to add ethernet to it... Guess I'll have to break down and update to a newer arduino board with built in ethernet.

The RTC board will be added on later - the Due boards are only 3.3v compatible, so most 5v boards won't work.

Found several that look to be 3.3v compatible... DS3231 High Precision Clock Module

Also, these Adafruit PWM boards have a few advantages over the on-board PWM or other PWM-driver boards:

So the PWM function is obviously superior to that of the arduino board, but other than fan and LED channel controls, what are you likely to use a PWM signal for? Aside from the motor servos you mentioned earlier...

I used ITead Studio: http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html">http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html</a>[/QUOTE]

Ordered mine just a few minutes ago. How long from order until the time you got yours?

I also used the new PCB file with the smaller, less expensive, screw terminals. I did, however, decide to add 24 pin sockets to the PCB for easier upgrades as suggested by another user on RC. I picked up 10 of them for $7

[QUOTE=]The boards I got fit the MeanWell LDD-H series - LDD-1000H, LDD-350H, LDD-700H, etc..

Pick one with a Current Range close to, but preferably not more than, what the LEDs can handle at max power.[/QUOTE]
I overlooked that part in the original thread, thanks for the clarification. Most of the LEDs I'm going to be using are driven at a max of 700mA. I went with the LDD-600s to allow head room as you suggested, although antoher member on RC suggested exactly the opposite, which I found strange because it sounds like someone will be blowing quite a few expensive LEDs in the near future when they're powering a 700mA LED with a 1000mA driver and inadequate cooling.

Im still VERY new to the arduino thing, but I've been wanting to swap out my existing LEDs for some time for something with a little more full spectrum. Trying to take it steady as she goes and follow along here and RC.

The next thing I need to decide is whether to make a seperate enclosure for the arduino board and drivers or just put them in whatever enclosure I come up with.

 

[giulianom]

Ok, so I've encountered a problem...

The boards I ordered appeared to have the holes for the connectors drilled to the wrong size...

alt="" /></a>

The pins on the connector are 0.75mm - the holes are only 0.5mm.

The holes and pads needed to be 0.85mm for the pins to fit...


I may have to re-order the new style that uses the less expensive connectors...

Or, I can design my own boards pretty easily.

Maybe I'll try that, since it'll be another few weeks before I get the LDD drivers.

 

[jbadd99]

Keep in mind I ordered 10 of the newer style as well. Don't think ill be using then all, but you'll need new terminals.

I also picked up 7 LDD-1000s last night that should ship tomorrow.

 

[giulianom]

jbadd99;850203 wrote: Keep in mind I ordered 10 of the newer style as well. Don't think ill be using then all, but you'll need new terminals.

I also picked up 7 LDD-1000s last night that should ship tomorrow.

Where did you order the LDDs from that they shipped so quickly?


I may try to see if I can fit a larger number of LDD drivers on one board - I'm going to need 15 for mine.

The new terminals aren't a problem, I can get about 50 of them on eBay for less than $10...


Otherwise, I may need 3 of those newer style boards. Let me know when they come in.

 

[jbadd99]

http://www.onlinecomponents.com/keywordsearch.aspx?text=LDD-1000h">http://www.onlinecomponents.com/keywordsearch.aspx?text=LDD-1000h</a>

There was about a 24 hour turnaround time from purchase of my last set to my purchase of these, so I'm still waiting to see if they're shipping as quickly, however I did notice the quantity available went since my purchase.