0-99 7 segment Counter on LPC2148 ARM7 Development Board

Fig 1 7 Segment LED Display
0 – 99 7 Segment(SSD) Counter on LPC2148 ARM7 Development Board

What is 7 Segment Display(SSD)?  – A seven-segment display is a form of electronic display device for displaying decimal numbers (and some alphabets too). 7-segment displays are simply 7 LEDs placed in one same package.  To change the displayed value, we simply turn on or off different combinations of LEDs.


Types of 7 Segment : – There are two types of 7-segment displays: Common Anode(CA) and Common Cathode(CC).  In common anode displays, the anode of the LEDs are connected to one pin (usually connected to a power source).  In common cathode displays, the cathodes are connected to one pin (usually connected to ground).

Fig 2 Common Anode and Common Cathode Diagram Representation
This code is tested in Keil uVision 4. Developed for ARM LPC2148  kit of ALS Advanced Systems Board.
There are two multiplexed 7-segment displays LT543 (U8 and U9) on the board.
Seg_A connected to P0.16 
Seg_B connected to P0.17 
Seg_C connected to P0.18 
Seg_D connected to P0.19 
Seg_E connected to P0.20 
Seg_F connected to P0.21 
Seg_G connected to P0.22 
Seg_DP connected to P0.23 
Common cathode of U8 –> P0.28 
Common cathode of U9 –> P0.29

Values to be sent to the Ports:

In following table, we convert 8 pin’s 8 bit binary data into hex code and this data is sent to ports.
Fig 3 7 Segment Hex Numbers


ARM Code :


Download Code:

 To Download the Code click on the link below: