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Author Topic: 4 digit seven-segment display !  (Read 2015 times)
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Hello, I am new to arduino, just got it a few days ago smiley

So I have this 1 digit 7-segment display, I got it to work, displaying numbers and letters..

Now I want to use the 4 digit display, but it has 12 pins, and everything I find online is either 16 pins or 10 pins...

The following picture is a picture I took just now...


So I have 12 pins ...
I wish to know what pins to connect to the digital outputs, and what I connect to ground...
(Also, do I need 5v? Did not need for the 1 digit display.)

Thanks in advance, Hilmar. smiley
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you might have to probe it out, its 7 segments, 1 dp and 4 commons
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Quote
Now I want to use the 4 digit display, but it has 12 pins, and everything I find online is either 16 pins or 10 pins...

I did a quick search for led 4 digit and then clicked on two different displays that resembled yours.  Each came up with a link to a datasheet and both datasheets had the same pinout.

PIN          FUNCTION
 1                E
 2                D
 3               DP
 4                C
 5                G
 6     DIGIT 4 COMMON A/C
 7                B
 8     DIGIT 3 COMMON A/C
 9     DIGIT 2 COMMON A/C
10                F
11                A
12     DIGIT 1 COMMON A/C


Don
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You will need to multiplex the display. Drive the segments hi/lo as needed, then drive the common (anode or cathode) as needed to turn 1 digit on.
Earlier today there was a post that multiplexed by each segment. Little slower that was vs a whole digit at a time.
Whole digit needs a transistor to handle the common current from a digit. Single segment you can get by with just arduino pins.
Either case needs current limit resistor(s); 1 for each segment if driving the whole digit;1 per digit if multiplexing each individual segment.
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i have a display from lumex that looks identical to that, i use it with a max7219. let me know if you resolved your issue or not, i can share the code and send the data sheet, but like floresta said they're probably all the same pinout.
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The Max7219 would be an Ideal IC to use, easy, sketches available, libraries available and one 7219 can drive up to 8 digits and they can be cascaded, Too.

Bob
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Unless thats a common anode part, then the MAX7219 is not suitable.
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Unless thats a common anode part, then the MAX7219 is not suitable.

common cathode  smiley-grin
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There you go then, MAX7219 would be easy to use.
Connect segment pins to segments, connect 4 digit pins to the 4 common cathodes, and program away.
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