Connect with us

Newbie: Help wiring 7 segment display

Discussion in 'General Electronics Discussion' started by Arthur Yasinski, Jun 27, 2015.

Scroll to continue with content
  1. Arthur Yasinski

    Arthur Yasinski

    2
    1
    Jun 23, 2015
    I bought the following MX035 7-segment display but I am very new to electronics and don't know how to wire it up. I soldered wires to each of the areas of the anode section of the board (A)....specifically defagbcpv

    I thought I would be able to test the soldering by hooking the + from a 12V power supply to the "v" pin and then complete the circuit by hooking the gnd from the 12v ps to one of the other pins (e.g., "c"). My expectation was that the lower right segment would light up.

    But nothing happens. :(

    What am I doing wrong? Is the "v" pin not the common anode pin? and if not, what is?

    I feel really stupid, so appreciate the assistance.
    Arthur
     
    ver chan likes this.
  2. Arouse1973

    Arouse1973 Adam

    5,164
    1,087
    Dec 18, 2013
    Hello
    I don't quite understand the diagram at the bottom of the datasheet, it looks like they have the polarity around the wrong way. But from what you have said you have down it correctly. What I did notice is above the picture of the segment it shows some jumpers that look like they need to be linked for it to work.
    Adam
     
  3. Gryd3

    Gryd3

    4,098
    875
    Jun 25, 2014
    Can you give us a picture of the module?
    I don't like the diagram in the lower left... and the 'jumpers' Adam mentioned look like it's just displaying the internal connections... I want to be sure.
     
  4. ver chan

    ver chan

    55
    1
    Jun 27, 2015
    be cautious you might over supply the seven segment, please post some photos, and make sure you will connect it with right amount of voltage:eek:
     
  5. TedA

    TedA

    156
    16
    Sep 26, 2011
    Arthur,

    Thank you for linking the datasheet for your display. If someone wants pictures, Amazon is selling these things. The manufacturer is Maxx Tronic in Thailand.

    If I understand correctly, this module consists of a printed circuit board, 73 LEDs, and some resistors. The display does incorporate current limiting resistors, so it should work connected directly to the correct voltage source.

    From the data sheet, it appears that you will have to connect a number of jumpers before the display will work at all.

    Each segment must be jumpered to select the operating voltage. If you want common anode or common cathode operation, more jumpers must be connected to do this.

    For 12V operation, each segment requires two jumpers. There is a hole pattern on the PCB for each segment, labeled "J1 a" through "J7 f", plus "J8 P", for the decimal point. On each of these hole patterns, the first hole should be jumpered to the second hole, and the third hole jumpered to the fourth hole. This is illustrated on the PCB, about 1/3 of the way down from the top.
    J1_J8_Detail.jpg
    This gives you eight independent segments, counting the decimal point. You should be able to light each segment by applying 12VDC to the connections for that segment located about 2/3 of the way down the board. Connect positive to the upper "A" hole, negative to the lower "K" hole.
    Wiring_Detail.jpg

    It is not clear what the "V" connections might be. You will have to turn the PCB over and see. Perhaps they are just places to attach a wire lead for a common connection. In that case you would have to jumper this "v" hole to the 8 holes to its left.

    If you want common anode operation, you will have to jumper all 8 anode connections ( in the "A" row ) together.

    If your power supply has an adjustable current limit, you might set it to a fairly low current, perhaps 35mA, at first. This would be good for testing one segment at a time. Otherwise, add a resistor in series with the supply. Something like 220 or even 470 ohms. This will not give full brightness, but may avoid some smoke, if there is an error.

    It would be interesting to hear what you plan to do with the display, once you get it working.

    Good luck with your project.


    Ted
     
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

-