LED 14-segment Quad Alphanumeric Display. To use a 14-segment quad alphanumeric display it's almost exactly the same as the 7-segment display, but with a slightly different class name. Import the adafruitht16k33.segments module again but this time create an instance of the Seg14x4 class. 7 Segment Display Driver.
A seven-segment display is an electronic display device for displaying decimal numerals. Seven-segment displays are widely used in digital clocks, electronic meters and other electronic devices that display numerical information.
The schematic shows a BCD to 7 Segment Display for one of the digits of a digital clock. The following components are used.
A 7 Segment LED display generally has 8 input connections, one for each LED segment and one that acts as a common terminal. There are 2 types of 7 Segment LED digital display.
A BCD to Seven Segment decoder is a combinational logic circuit that accepts a decimal digit in BCD (input) and generates appropriate outputs for the segments to display the input decimal digit.
The truth table is extracted from the CD4511 IC datasheet. This truth table is interactive. Click on any row to see the respective 7 segment display output.
The input bits are D (MSB) to A (LSB) and the outputs are the segments a to g. For input values A to F, the display is blanked (outputs are all 0).
The logic circuit to implement the BCD to 7 Segment Decoder can be designed using the truth table,.
Learn by Doing
Design a BCD to 7 Segment Decoder to deepen your understanding of the circuit.