Twitter Torch - Twitter messages in a glass tube

The USB supply is 2A so I don’t see any issue.

I remember someone telling me to use a 6V powet supply or something.

Don’t find it a problem with the beefy supply :slight_smile:

OH yes WS2812B they are :wink:

its not the supply that’s the problem its that the spark pins can only sink 20mA each, plus the regulator can only put out 500mA total.

you may be able to do it using vin but i’m surprised you’re not having issues with the end led’s not lighting or the strip dimming with usb power.

you should think about a transistor or mosfet or a separate supply for the leds in the long term.

@sej7278, the WS2812B RGB LED strips use on-board controllers for every LED. All that is needed is a CLK and DATA line to make the entire strip work. Power is supplied separately. So, the USB adapter powers both the Core and the LED strip and the SPI MOSI and SCK lines are used for data and clock, like an SPI device. That is the beauty of those “smart” LED strips. :smile:

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Don’t even need the CLK with the WS2812B @peekay123 :wink:

Just 5V Data Gnd

i’m totally lost now. i’ve used led strips, admittedly 12v analogue ones not ws2812b’s, but they need to get their power from somewhere or are the digital ones multiplexed at incredibly high rates or something so that only a dozen are actually on at a time rather than 300?

sorry if this is going a bit off-topic

@kennethlimcp, your’re right!

@sej7278, the analog strips are all or nothing. You control ALL the LEDs in that strip at the SAME time. The ws2812b LED strips are INDIVIDUALLY ADDRESSABLE!! That means that your code can talk to EACH LED separately from the others. That’s why they are more expensive but infinitely more flexible. As for power, you need to supply enough to power the worst case scenario. In the case of the twitter torch, no all LEDs are on at the same time, and not at full brightness so @kennethlimcp can get away with a 2A supply. If all the LEDs in the strip were set to full brightness white then he would more likely need a 5A supply. :smile:

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I’ll probably buy them if i need them at 5A but totally dislike the idea of a bulky power supply just for this cool little guy :smiley:

UPDATE

This was on my mind the whole day till i finally managed to check this up.

There’s a protection diode on the USB line which is 30V, 3A so pulling more current through is going to blow things up!

Luckily i did not fire up the strips fully and the supply only gives 2A :wink:

What i would do is to connect to Vin and bypass the diode instead!

@kennethlimcp, on my torch, I connected a 5V 3A supply to Vin on the core AND to the LED strip. That is, I did not power the core via the USB connector. :smile:

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Hey I am really interested in making this for my room! Where did you get the acrylic tube? I dont have any lying around in my house, and I cant seem to find the right length/diameter online. Can anyone direct me to where to get the Tube, or it would be great if @Ruedi could share where he got his. thanks

edit: And where can I find the code for this project? I see above that some java code is posted? How can I use that? a little confused :frowning:

And I was directed to Ebay, and I found my tube! Thankyou everyone for helping. link for anyone else also looking: http://www.ebay.com/itm/251410847567?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

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@hassaan22,

When I made my torch I didn’t use a see through tube. I had some industrial cardboard tube (the tube they wrap fabric onto) so I used that. I added more and more pieces of paper ontop of the tube to build the diameter up so that the LED’s lined up approximately vertically. This gave a better effect. I have powered mine straight from the USB through the core. It runs most of the time in the corner of our living room as a feature lamp. It does not seem to get hot or have any problems. Mine is made from a 4 meter strip of 60/m (240 total) Ws2812 LED’s. Since the Ram optimisation I have had no trouble with it. It just works. :smile:
Thanks @luz

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Done this up and made it pretty for public demo in September :wink:

Powering off a battery bank for now. I will be working on the firmware now that it’s looking awesome as a completed hardware!

Need to shrink the words size and make the colours more distinctive and the messages more readable.

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My glass tube is a flower vase an I got it from a local furniture department store, The LED strip is rubber encapsulated and therefore its easy to put it inside the glass tube what gives it a nice elegant design. The code I posted are the changes I made to combine the two projects: Message Torch and Twitter Magnet. If you only want to send messages to the torch without involving Twitter you see the whole project at https://community.spark.io/t/messagetorch-torch-fire-animation-with-ws2812-leds-message-display/2551

Hey Ruedi! Thanks for the reply. You cleared up a lot for me and have already ordered all the parts online! Just one confusion: why is your code written in Java, and how and where am I supposed to use it? Do I just copy/paste this on the web IDE? I thought Spark worked on C++? Sorry if it’s a dumb question, :frowning:

Awesome! Great idea, and it looks really cool. Thanks for sharing! I am now on my way to making my own! Will share as soon as I am finished! Patiently waiting for all the parts right now :blush:

@kennethlimcp Try setting a background color similar to (and dimmer than) the scrolling text color. Also possibly try masking flame bits when they go behind text area, so they are dimmed and ‘behind’ text.

Maybe draw the text with a blending function like this:

void crossFade(byte aValue, byte anAlpha, byte aValue2, byte anAlpha2, byte &aOutputA, byte &aOutputB)
{
  // alpha is 0 to 255 (0 to 100% opacity), higher anAlpha gives brighter thisBright, lower anAlpha2 for dimmer nextBright
  // pass background color used for aValue2 or just 0 for no color
  //Painter's algorithm, 'over' operator
  aOutputA = ((aValue*anAlpha)>>8) + ((aValue2*(255-anAlpha))>>8);   
  aOutputB = ((aValue*anAlpha2)>>8) + ((aValue2*(255-anAlpha2))>>8);
}

(Should probably mention this color over with alpha values must be done for R, G, B individually)

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I’m looking at reducing the text size (height and width) but haven’t gotten to it yet!

Should be messing with that in August…

Hi, I just did little changes in the java script code (decribed at the begin of this disussion) of the twitter magnet project. The twitter magnet project has java script involved which runs on Computer. It fetch data fromt the Twitter and send it to your Core via the Spark Cloud. I doesn’t work to just copy java script into WEB IDE, the how to process is described @ https://github.com/spark/twitter-magnet

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When you are messing about with this could you have a look and see if it is possible to easily adapt the code to turn the torch into a clock. I was thinking that this could be achieved with spark time? http://docs.spark.io/firmware/#cloud-functions-time . I don’t know how to alter the code to use spark time. Would that be easy?

@Julian, it would be very straight forward to do that. Would you want the time showing always or perhaps every minute?

I was thinking constantly, but now you mention it could a variable be set to qualify the delay between reports?

Thank you very much.
:smile: