KIT INCLUDES
- Arduino uno with USB Cable – 1
- Resistor 220 ohm – 5 pcs
- Single stand wire 2m - 1
- 7 Segment display – 1
- Jumper wire (male to male ) – 40 pieces
- Breadboard 400 point - 1
Introduction
In this project, we are using 7 segment display to make a countdown launchpad which typically used in space shuttle launch system. Seven segment display is the most common device used for displaying digits and alphabet. One can see a device in TV shows counting down to ‘0’, these are nothing but seven segments.
HARDWARE REQUIRED
- Arduino uno with USB Cable – 1
- Resistor 220 ohm – 5 pcs
- Single stand wire 2m - 1
- 7 Segment display – 1
- Jumper wire (male to male ) – 40 pieces
- Breadboard 400 point - 1
SOFTWARE REQUIRED
Arduino IDE 1.8.5 (programmable platform for Arduino)
Click To Download: https://www.arduino.cc/en/Main/Software
SPECIFICATION
7 segments Led display
Common Anode: All the Negative terminals (cathode) of all the 8 LEDs are connected together. All the positive terminals are left alone.
Common Cathode: All the positive terminals (anode) of all the 8 LEDs are connected together. All the negative thermals are left alone.
1. Common Anode Seven Segment Display
In common anode type, all the anodes of 8 LED’s are connected to the common terminal and cathodes are left free. Thus, in order to glow the LED, these cathodes have to be connected to the logic ‘0’ and anode to the logic ‘1’.
Below truth, the table gives the information required for driving the common anode seven segments.
Segments inputs |
7 Segments Display Output |
||||||
a |
b |
c |
d |
e |
f |
g |
|
0 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
1 |
0 |
0 |
1 |
1 |
1 |
1 |
1 |
0 |
0 |
1 |
0 |
0 |
1 |
0 |
2 |
0 |
0 |
0 |
0 |
1 |
1 |
0 |
3 |
1 |
0 |
0 |
1 |
1 |
0 |
0 |
4 |
0 |
1 |
0 |
0 |
1 |
0 |
0 |
5 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
6 |
0 |
0 |
0 |
1 |
1 |
1 |
1 |
7 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
8 |
0 |
0 |
0 |
0 |
1 |
1 |
0 |
9 |
In order to display zero on this segment, one should enable logic high on a, b, c, d, e and f segments and logic low on segment ‘g’. Thus, the above table provides data on seven segments for displaying numerals from 0-9.
2. Common Cathode Seven Segment Display
As the name indicates cathode is the common pin for this type of seven segments and remaining 8 pins are left free. Here, a logic low is applied to the common pin and logic high to the remaining pins.
Segments inputs |
7 Segments Display Output |
||||||
a |
b |
c |
D |
E |
F |
g |
|
1 |
1 |
1 |
1 |
1 |
1 |
0 |
0 |
0 |
1 |
1 |
0 |
0 |
0 |
0 |
1 |
1 |
1 |
0 |
1 |
1 |
0 |
1 |
2 |
1 |
1 |
1 |
1 |
0 |
0 |
1 |
3 |
0 |
1 |
1 |
0 |
0 |
1 |
1 |
4 |
1 |
0 |
1 |
1 |
0 |
1 |
1 |
5 |
1 |
0 |
1 |
1 |
1 |
1 |