common cathode 7 segment display pin diagram

If none of the segments light up at first attempt, leave the power jumper connected to Display pin 1 and step the ground jumper pin-by-pin counterclockwise from pin 3 to pin 10, observing the display.

Remember, we need to have a power jumper on the anode side of a segment and the ground jumper on the cathode before that segment will light. Both of the jumpers could be on common pins.It is also likely, particularly at the beginning of the test, that your jumpers are not connected to the same segment, in which case there is no circuit and nothing will light up either.If your test connection polarity is backwards, nothing will happen. Each segment of the display consists of at least one Light Emitting Diode or LED that only lights up when positive voltage is applied to the anode and there is a path to ground at the cathode.What happened? Probably nothing - and that is OK. Finally, touch a jumper from the ground rail to pin 2 of the display as shown on the above diagram. Then connect a jumper wire from the resistor to pin 1 of the display. Position the 7 Segment Display so that the top row of pins are separated from the lower pins by the center gutter that divides the breadboard. We are limiting current flow with the resistor to protect LEDs in the segments from burning out. I am using a 220 Ohm resistor in this example, but anything in the range of 180 to 1,000 Ohms should work for mapping the display pins. It doesn't matter which way the resistor is oriented. Connect a resistor from the power rail to an unused column of the breadboard. Run both the power and ground to their respective horizontal rail rows at the top of your breadboard. I suggest using between +3.6VDC to +5VDC power and a ground from batteries or a bench top power supply. Prepare a test circuit according to this diagram:īegin with a power source. Let's pretend we don't know this and determine the pin mapping by inspection. Many single digit 10 pin displays have the common pins in the center position of each row. From your bottom left, the first pin is number 1 and the numbering continues sequentially in a counterclockwise direction with pin 5 being at the bottom right, pin 6 at the upper right and concluding with pin 10 at the upper left. The pins are numbered similarly to Integrated Circuits. As it turns out, there are usually an even number of pins on these displays, with the 'extra' pins being tied together as part of the 'common' set. However, when I counted the pins on my 5161BS display, there were 10 - five on the bottom row and five on the top. With one common pin, there should be at least 9 pins. Because most displays also include a decimal point, colon or apostrophe, there are usually eight segments, seven for the digit and one for punctuation. The idea behind having a common cathode or anode display is that by sharing either positive voltage or a path to ground, fewer pins are necessary than if every segment had it's own pair of cathode and anode pins. Individual segments are lit when their pin receives sufficient positive voltage. Common Cathode: A common path to ground is shared by the segments.Segments are lit by setting their individual pins to Ground. Common Anode: In this type of display, a positive voltage source is shared by the display segments.There are two main types of 7 Segment LED Displays: We can start by outlining some of the properties that apply to these displays in general:

Let's assume, however, that the search did not turn up anything useful and we will have to get this thing working without any additional information. My very first search result for '5161BS' returned a six page data sheet that clearly described everything I need to know about using this display and more. You may already have a How-To, tutorial or FAQ that describes your display, but if you don't, a Google search on anything that looks like a part number on the display should come up with enough information to get started. The difference between the picture and the display I will be using is that the number stamped on mine is 5161BS and that is all I know about it so far.

Common cathode 7 segment display pin diagram