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Topic: 4 digit seven-segment display ! (Read 2311 times) previous topic - next topic

Hilmar

Hello, I am new to arduino, just got it a few days ago :)

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. :)

Osgeld

you might have to probe it out, its 7 segments, 1 dp and 4 commons
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

floresta

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

CrossRoads

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.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

grendle

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.

Docedison

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
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

CrossRoads

Unless thats a common anode part, then the MAX7219 is not suitable.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

grendle


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


common cathode  :D

CrossRoads

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.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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