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May 13, 2014, 05:34 PM
A different attitude to RC
extremewing's Avatar
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Mini-HowTo

Foldable LED clock with 16" character height


For a while now I have had a large LED display that I made using LED strips and an Arduino type controller.

The biggest benefit with this clock is it's portability. It folds up into a briefcase size yet has large characters to enable it to be seen from further away.

This thread is to publish the design of the sign and will serve as a resource for anyone wanting to make one or those who got parts from me and want to compete the build.

The sign is controlled using Bluetooth and at the moment, an Android app (F3K Master) is used to control it.

The sign is capable of displaying full color and in F3K Master the color indicates the window state
- White for break or prep time
- Yellow for test time just before the window
- Green for the flight window
- Red for the landing window

The sign is constructed to be very portable and also as cheap as possible although it does take some time to make.

Over the coming weeks, I will publish all the info to make one.
Last edited by extremewing; Apr 15, 2015 at 12:50 PM.
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May 13, 2014, 05:35 PM
A different attitude to RC
extremewing's Avatar
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Parts list


Last edited by extremewing; May 14, 2014 at 09:15 PM.
May 13, 2014, 05:35 PM
A different attitude to RC
extremewing's Avatar
Thread OP

Making the seven segment digits


The digits are made from WS2812B LED strips. LED strips provide a relatively easy and cost effective way of making this sign.

The PCB's were designed to help join the strips, effectively creating one continuous strip of LED's in the shape of a seven segment digit. The control signal feed directly from the last led in the strip on one digit to the first LED in the next.



I will post more details here soon.

New: I have attached a zip file with three circuit board designs done in EAGLE.

"Teensy + BlueSMiRF Silver.brd" is the design for the control board
"Colon Joiners.brd" the design for the colons (there are three sets and you would likely only need one)
"LED Joiner Large Tracks.brd" - a set of boards for one character (you would likely need four of these)

Once open in EAGLE, before printing the boards, press the Tools > Ratsnest menu to create the ground plane fill.

If you want a really good system to make home made PCB's, I recommend PCB "Fab-in-a-box": http://www.pcbfx.com/
It's even sold by DigiKey: http://www.digikey.com/us/en/ph/puls...red%20Products

I got the Apache laminator they refer to and it works perfectly.
Last edited by extremewing; Jun 18, 2014 at 06:58 PM.
May 13, 2014, 05:36 PM
A different attitude to RC
extremewing's Avatar
Thread OP

Once the digits are ready, you can start assembling the sign.


The controller outputs three signals to control the sign in three main parts:

Connect the relevant signal wire from the controller to the left two digits, the right two and the dots only after orientating the left and right digits in the correct way.

- The left two digits "signal in" must be on the RIGHT - that is the (bottom right vertical) first LED strip arrows would point DOWN
- The right two digits "signal in" must be on the LEFT, that is the (top left vertical) first LED strip arrows would point UP
See "Identify SIGNAL IN side" in the pictures if this description is a bit hard to understand?

I will also post a wiring diagram of sorts soon to make this more clear.
Last edited by extremewing; May 15, 2014 at 08:09 PM.
May 13, 2014, 05:36 PM
A different attitude to RC
extremewing's Avatar
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Software and related info


The sign uses a Teensy3.0 to drive the LED's.

It is an Arduino compatible board and runs firmware I wrote to drive single strips to mimic a seven segment display.

F3K Master drives the sign through Bluetooth but it is possible to include the functionality in other apps.

The sign can be sent the following commands:

Brightness
Color
Time value
Last edited by extremewing; Aug 20, 2016 at 01:13 PM.
May 13, 2014, 05:37 PM
A different attitude to RC
extremewing's Avatar
Thread OP
Reserved for info on making the case.
Last edited by extremewing; May 14, 2014 at 02:43 PM.
May 13, 2014, 05:39 PM
A different attitude to RC
extremewing's Avatar
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Testing, troubleshooting and repair


BEFORE CONNECTING POWER, MAKE SURE YOU HAVE THE POWER SUPPLY CONNECTED PROPERLY.


It is possible to get hasty and connect the 12V directly to the sign without the 5V converter - I DID THIS ONCE!

When making the sign, it is important to make sure you have no short circuits, reverse polarity or poor connections.

If possible, use a multi-meter to verify there is a connection from the bottom dot's power to the very end solder pads on both left and right sides. Also using the meter, verify the + and - do not have a short between them.

It is also advisable to include an inline, 15A or 20A fuse to help protect against reverse polarity or short circuits.

Using USB to power the sign is useful to verify basic functionality of the center dots and control board as well as up to one panel.

If possible, use a bench power supply with a current of 3 amps or less to test. That way, if there is a problem, you do not have enough power to seriously damage parts.

NOTE: Reverse polarity is very bad and great care should be taken to avoid it, particularly from the 5V converter to the LED panels.

Having said that, during development, I mistakenly connected power reverse polarity, 12V directly to the 5V LED's and more. If this happens, the worst will be a few LED's failing (immediately or over time) and replacing the failed one will usually do the trick.
Last edited by extremewing; May 15, 2014 at 02:22 PM.
May 13, 2014, 05:44 PM
Mike M.
like.2.fly's Avatar
Reserved for my response...

SWEET!
Last edited by like.2.fly; May 13, 2014 at 08:36 PM.
May 13, 2014, 08:02 PM
UAV Test Pilot
Doug Cronkhite's Avatar
This was GREAT for the IHLGF, Adrian!
May 13, 2014, 08:18 PM
A different attitude to RC
extremewing's Avatar
Thread OP
Quote:
Originally Posted by like.2.fly
Reserved for my response...
Sorry to reserve so many posts Mike! It is fairly complex and I was not sure how many "subjects" there may be. I will delete unneeded ones later.
May 13, 2014, 08:36 PM
Mike M.
like.2.fly's Avatar
These clocks are wonderful. I love having them at our local comps, and most of the regional ones we go to. They make playing poker much less complex, and are really handy to glance at when waiting for your last launch in the ladder, or last 2, or last 3, or seeing how much time is left during prep time. Huge kudos to Adrian for designing a really nice and portable system that works great. I see it becoming a standard at all F3K comps in the future, like it already has out west. Great job AD!
May 14, 2014, 12:31 AM
I do this for fun!
Extremewing,

It looks fantastic!

From how far away can it be read, roughly?
May 14, 2014, 01:13 AM
Location: Zurich/Sweden
funkz's Avatar
Adrian please sign me up for the PCB's or any base electronic components required to build this from scratch (if you decide to sell base kit components). I do have a couple of arduinos, one even with the BT module. So please let me know if there's a chance to buy from you a kit.
Last edited by funkz; May 14, 2014 at 09:21 AM.
May 14, 2014, 09:10 AM
Throw it like you hate it
RCPC's Avatar
Quote:
Originally Posted by like.2.fly
These clocks are wonderful. I love having them at our local comps, and most of the regional ones we go to. They make playing poker much less complex, and are really handy to glance at when waiting for your last launch in the ladder, or last 2, or last 3, or seeing how much time is left during prep time. Huge kudos to Adrian for designing a really nice and portable system that works great. I see it becoming a standard at all F3K comps in the future, like it already has out west. Great job AD!
You said everything I would have said. These displays are so valuable in contests. I love them! Thanks for offering them, Adrian. When can we buy the kits from you?
Paul
May 14, 2014, 10:15 AM
Transplant Chey WY from Reno
Thermaln2's Avatar
Quote:
Originally Posted by RCPC
You said everything I would have said. These displays are so valuable in contests. I love them! Thanks for offering them, Adrian. When can we buy the kits from you?
Paul
I have to second the statement of Paul.

They were used at Poway and even on the bright sun you could see them. I found them very useful and it provided me with a quick glance all the I time info I needed if my timer was a few steps from me and I could not communicate as well.

I would like to build a set for our local flying and to perhaps have a contest up here in Reno, where Poker and gambling really means something !

Chris


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