Connect with us

Help with 7 segment display

Discussion in 'General Electronics Discussion' started by lefam, Dec 14, 2010.

Scroll to continue with content
  1. lefam


    Nov 18, 2010
    Hi guys.

    I have bought some 7 segment LED displays (common anode). But the pins are not arranged like in 7 segment display below.


    My displays have the pins in the left and right side (instead of in the top and bottom like in picture above).

    Can you help me using these displays.

    In the website I bought them they had this diagram:

    Please help me to use these displays.
  2. shrtrnd


    Jan 15, 2010
    Find a data sheet on your part number from the web.
    I am assuming your only problem is that you don't know the pin-outs (which pins to which segments). They'll be listed on the FULL data sheet.
    If you're really in a bind, trial and error, will get you which segment to which pin.
  3. davenn

    davenn Moderator

    Sep 5, 2009
    assuming that your displays are the LDS5161xx series as the data you have shown from where you purchased them then....
    all the info is listed on the data in the image above its all there all you need to know :)

    looking at the front of the display, pin 1 is in the bottom left corner and its segment E

    ARE your displays the LDS5161xx series ? you havent told us what they are ...
    rather you have infered they are the ones indicated in your data image

  4. lefam


    Nov 18, 2010
    SOLVED. Thank you guys.
    I found out with trial and error. I figured out that the diagram does not correspond to the display I bought.
  5. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    Jan 21, 2010
    I know I'm late in on this, but I have had this problem several times.

    I generally don't even bother to look for a datasheet any more unless I need to know more than the pinout :)

    You connect a multimeter probe (either one) to a pin at random and with the meter on an ohms range, run the probe along all the other pins, watching the display, not your meter.

    One of three things will happen (your goal is to get to number three):

    1) Nothing lights up. Swap the probes up and repeat. (if you already have, you picked a non-connected pin. Pick another one)

    2) A single element lights up in some position for the second probe. This is the common connection. Connect the meter probe to this point and use the other probe to sweep along the pins.

    3) the segments will light up in some order displaying the segments -- this means you have found the common connection and have the polarity right -- go ahead and document the pins.

    If the display is a multiplexed unit, the procedure can be logically extended by one more step.

    4) The other pins are either NC or the other common anodes (cathodes) picking a segment at random, probe these other leads to determine which position they are common to.
  6. lefam


    Nov 18, 2010
    I am learning that the multimeter in ohm (resistor) mode conducts current! How does it work?
    I have figured out that when I test an LED with a multimeter in diode mode it lights up (a bit).

    I think it is possible to make the trial and error using the multimeter in diode mode. Right?

    Can you explain me why the LEDs light up in resistor and diode modes?
  7. barathbushan


    Sep 26, 2009

    The principle of measuring resistance by a multimeter is that it sends out a current , and the current creates a voltage drop [ IR ] across the resistor R , the voltage drop then is calibrated to read the appropriate resistance .

    In a similiar way the in diode test ,the meter passes current through a diode , thereby detecting its knee voltage drop at its forward resistance .

    THE CURRENT in the above two cases make the led's glow when connected .

    is working by this method to see if the seven segment is common anode or common cathode type and if your 7 segment display is working properly
    Last edited: Dec 15, 2010
  8. lefam


    Nov 18, 2010
    Thank you.......
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day