PAGE 093 OF 150 · DISPLAYS & INDICATORS
Seven-Segment Display Basics
Segments labelled a to g combine to form digits.
LED SYMBOLTriangle points from anode to cathode; the arrows show light leaving the part.
Segment names
The segments are labelled a (top), b (top right), c (bottom right), d (bottom), e (bottom left), f (top left) and g (middle), with dp for the decimal point.
Digit patterns
- 0: a b c d e f
- 1: b c
- 2: a b d e g
- 3: a b c d g
- 4: b c f g
- 5: a c d f g
- 6: a c d e f g
- 7: a b c
- 8: all seven
- 9: a b c d f g
Driving
Use a resistor on each segment. A decoder such as the 7447 or 4511 converts four binary bits into the pattern, saving pins.
REMEMBER
A seven-segment digit is seven small LEDs arranged to draw numbers.Try it yourself
Sketch the circuit on paper first, calculate the values, then build it on a solderless breadboard using a low-voltage supply. Measure with a multimeter before you make anything permanent.
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