Segment Displays

Hi, I am slightly confused about the 7 segment 4 digit displays. Some segments have a total number of 12 pins and others have 16. What is the difference between them and what difference will it make to the Arduino programming common anode over common cathode and how they differ. And which is preferable for me as I am a beginner. Also they come in various sizes like 0.56" etc. I have a standard size breadboard so which size do I need? Thanks A lot.

Generally you have 7 pins for the segments and an extra pin for the comma or punctuation.

This requires 12 pins, and some displays have more, they are simply unconnected and You do not connect them.

If you want us to give you advice on what is best, please give some links to some possibilites we can chose from. Generally 7-segment LED displays have very short pins and may not get a good contact in a solderless breadboard.

// Per.

There are displays with just 7 segments, ones with 7 segments and a dot, 7 segments and 2 dots, and there's also ones with more than 1 common pin.
You will have to look up the datasheet of each display to know it is to your needs.
That datasheet will also tell you the available size, all you need to do is measure your breadboard and compare.

Zapro:
Generally you have 7 pins for the segments and an extra pin for the comma or punctuation.

This requires 12 pins, and some displays have more, they are simply unconnected and You do not connect them.

If you want us to give you advice on what is best, please give some links to some possibilites we can chose from. Generally 7-segment LED displays have very short pins and may not get a good contact in a solderless breadboard.

// Per.

http://www.ebay.co.uk/itm/7-Segment-Display-Red-Common-Cathode-0-52-13-2mm-Kingbright-x-4-/140891922080?

The above link is a single digit segment so will this be a common use for me?

7 segment 4 digit display with 12 pins http://www.ebay.co.uk/itm/1-Pcs-0-56-7-Segment-4-Digit-Super-Red-LED-Display-Common-Anode-Time-12-pins-UK-/290682665259?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item43ae09792b

7 segment 4 digit display with 16 pins http://www.ebay.co.uk/itm/0-39-7-Segment-4-Digit-Red-LED-Display-Common-Anode-Time-12-pins-UK-/160948595645?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item257948abbd

Any ideas? I am planning on buying all of them but I just want to make sure I have the right size for my standard breadboard. And where will I get the data sheet for these Segments? Thank You.

The display with 16 pins has the 7 segments + DP for each digit, and the 4 commons (12 pins so far.) Then it has a colon and an "upper decimal point", each with both ends on pins (4 more pins.)

The plastics for these displays tend to be standardized, so just because a display LOOKS like it has a colon or decimal points, doesn't mean it actually has LEDs populated in all places. If it's only got 12 pins, it probably doesn't have both colon and decimal points...

I also have in my possession a large number of 4-digit displays (from eBay) where one of the digits has a separate lead for its "F" segment...