The seven segments displays
are the oldest yet one of the efficient types of display used in embedded applications. This display has nothing more than 8 LED inside it. These 8 LEDs are separated into each segments which can be named as a, b, c, d, e, f, g, DP as shown in the picture above. These entire 8 segment LEDs have one end of their pins pulled out of the module as shown above and the other ends are connected together and pulled out as the Common pin. So to make an LED of a particular segment glow we just have to power common pin along with the segment pin. This way we can power more than one segment at a time to represent the numeric number 0-9 and also few Alphabets as shown on the graphic image below. We also have an option to show a decimal point using the DP pin.
– Low current operation
– Better, brighter and larger display than conventional LCD displays.
– Current consumption: 30mA / segment
– Peak current: 70mA
– Average power consumption : 36 mW
|Pin Number||Pin Name||Description|
|1||e||Controls the left bottom LED of the 7-segment display|
|2||d||Controls the bottom most LED of the 7-segment display|
|3||Com||Connected to Ground/Vcc based on type of display|
|4||c||Controls the right bottom LED of the 7-segment display|
|5||DP||Controls the decimal point LED of the 7-segment display|
|6||b||Controls the top right LED of the 7-segment display|
|7||a||Controls the top most LED of the 7-segment display|
|8||Com||Connected to Ground/Vcc based on type of display|
|9||f||Controls the top left LED of the 7-segment display|
|10||g||Controls the middle LED of the 7-segment display|
Common Anode (CA) 7 Segment Display
The common anode display is commonly called CA display. In this type the common pin on the 7-segment display is connected to all the eight Anode pins of the LEDs. So In order to make this type of seven segment display to work we should connect he Com pin to the Vcc (+5V typically) and ground the required segment pin to turn it on.
– Used in applications where font size is required to be bigger
– Microcontroller Independent, hence used in small circuit projects
– Used in combination with four segments to display measurement/sensor value with four characters
– Has bright illumination, hence used where display are required to work in low light or dark conditions