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Hi there, I need a specific kind of display like this one ;

Anyone know the name of this displays?
Where can I find something like this? Is it possible to control this with arduino?

Thank you
« Last Edit: May 09, 2012, 10:09:45 am by highroller » Logged

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Anyone know the name of this displays?

You have five '7-Segment' displays.  Each of the displays has seven LEDs or groups of LEDs (maybe one or two more for the decimal point).  These LEDs may have all of their cathodes tied together and have individual anode connections, or vice-versa.  Most likely the five displays are multiplexed.


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Where can I find something like this?

Now you know what to look for so try a search.
Where you live would be a consideration, that's why your profile has an entry for your 'location'.


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Is it possible to control this with arduino?

Absolutely.  You might want to look through the 'LEDs and Multiplexing' section of the forum.  It's a toss-up as to which section is more appropriate.

Don
« Last Edit: May 09, 2012, 10:53:01 am by floresta » Logged

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That looks like it may be a Vacuum Fluorescent Display (VFD).  I don't think you can drive one directly with an Arduino since they require high voltages but I expect there are driver chips that will allow the Arduino to control one.

Of course if it is just a blue LED display then the Arduino can drive it directly.
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I was thinking in terms of a poorly exposed picture of an LED display, but a VFD makes more sense.

Don
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Might be my screen, but the colour just doesn't look "right" for a VFD. Anyway, an easy way to tell if it is or it isn't is whether or not it's glass-encapsulated, and has tiny little grid lines running across it. smiley

7 segment LEDs are a piece of cake to drive, and there are many options available and loads of different driver ICs for both common cathode/anode types. If you don't want to spend a lot of money, but don't mind the waiting time, chinese eBay sellers can probably sort you out once you know what you're looking for.

IF you find you've got a VFD, and it's not a chip-on-glass type (where the control circuitry is integrated into the device), I personally wouldn't bother with it as it's too much hassle for not that much reward.
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You guys are great! Really appreciated.

This little puppy is what I'm lookin for.
http://www.sparkfun.com/products/9191

Can someone look at that tutorial http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Components/General%20IC/arduino_segment_led.zip and maybe simplify it for us newbies?
I simply need to make a 5 digit whole led display. And then also need to control 10 of those five-digit displays with one arduino controller.

Any suggestions?

Thank you.
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Any suggestions?

Here are a few:

The 'tutorial' uses a non standard technique to identify the segments.  The segments are ALWAYS identified by letters, typically lower case, starting with 'a' at the top and proceeding clockwise (analog clock) and ending with 'g' in the middle. The Sparkfun pinout is generally correct for all devices with 10 pins as well.  If you notice you can put the device in upside down and it will still function normally.  As a matter of fact this is sometimes done deliberately so that two adjacent devices can have their decimal points function as a colon.

Ultimately you are going to need a lot of I/O pins.  For each five digit display you will need seven pins for the segments (eight if you need the decimal point) and five more for the anodes (or cathodes).  You should consider an I/O extender, possibly something like a 'Centipede Shield' http://docs.macetech.com/doku.php/centipede_shield.

I suggest that you start by getting one digit functioning and display the output of a binary counter on that display.  Next you should expand to two digits, and finally five digits.  You should do all of this using just the Arduino at first, and then with your I/O extender.


Don
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Thanks Don,

I think as you said, I should probably go ahead and start with the one digit testings, then work my way up.
So, basically, with right components, I should be able to use "one arduino" to control 10pcs of 5digit seperate 7segment led groups?

Best.
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You should be able to do it using only three pins, plus power/ground with the right driver chip! So no need for I/O expanders unless you really want them.



An example I built using the MAX7219 driver. Only works with common cathode displays though, so if you have common anode you'd need something else... but it was pretty easy to get running and I'm hardly an expert user!
« Last Edit: May 09, 2012, 12:36:03 pm by BulletMagnet83 » Logged

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So, basically, with right components, I should be able to use "one arduino" to control 10pcs of 5digit seperate 7segment led groups?
Theoretically you should be able to do this.  It's going to be a wiring nightmare.

I forgot to mention the series current limiting resistors.  You need one for each segment of each digit of each display.  No, you cannot get away with using a single resistor in the common lead of each digit.


I forgot to answer this:
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Can someone look at that tutorial http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Components/General%20IC/arduino_segment_led.zip and maybe simplify it for us newbies?

That would be a waste of time.

In general what you need to understand that there is no mathematical relationship between the number that you want to display and the magic binary values that you will use to create that number on your display.  The array is used to create the required relationship. 

With a common anode display you will output a '1' to either of the 'Common Anode' pins and you will use the array to output '0' (via a current limiting resistor) to the appropriate segments.  Therefore each '0' in the array signifies a segment that will be energized.

With a common cathode display you will output a '0' to either of the 'Common Cathode' pins and you will use the array to output '1' (via a current limiting resistor) to the appropriate segments.  Therefore each '1' in the array signifies a segment that will be energized.


Don
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You should be able to do it using only three pins, plus power/ground with the right driver chip! So no need for I/O expanders unless you really want them.

You can do just about anything using only three Arduino pins.  Just substitute 'the right microprocessor' for 'the right driver chip' in your statement above.


Don

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I think I was correct in my original wording, since I don't know what the "correct driver chip" is, without knowing if it's a CC or CA display smiley-wink But in any case, whatever it is, is likely to only need the three pins to control it.
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You should be able to do it using only three pins, plus power/ground with the right driver chip! So no need for I/O expanders unless you really want them.



An example I built using the MAX7219 driver. Only works with common cathode displays though, so if you have common anode you'd need something else... but it was pretty easy to get running and I'm hardly an expert user!

Great work.
I also want to be able to control those 5 digit leds dynamically with a data feed coming to the arduino board from a computer (for example : led no 3 = 25345 or led no 1 = 00293) so that's another weird part.
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I also want to be able to control those 5 digit leds dynamically with a data feed coming to the arduino board from a computer (for example : led no 3 = 25345 or led no 1 = 00293) so that's another weird part.

That's not really weird nor hard to implement.  In reply #6 I recommended a counter to generate a source of changing data.  When that is working you just substitute your data feed from the computer as the source.

Don
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The MAX7219 is an interesting part... GREAT for 7 seg displays AND it makes a great driver for an 8X8 matrix display. Don't forget the Holtek HT1632 driver as it it is a most versatile LED driver too.

Doc
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