MIKROE-455 mikroElektronika, MIKROE-455 Datasheet - Page 21

• Manufacturer Part Number: MIKROE-455
• Description: Development Boards & Kits - 8051 EASY8051 V6 DEVELOPMENT SYSTEM
• Manufacturer: mikroElektronika

Specifications of MIKROE-455

• Rohs: yes
• Product: Development Kits
• Tool Is For Evaluation Of: AT89S8253
• Core: 8051
• Interface Type: CAN, MMC/SD, RS-232, USB
• Operating Supply Voltage: 5 V, 9 V to 32 V
• Data Bus Width: 8 bit
• Description/function: Development Board Only, GLCD, LCD, DS1820, Serial Cable not included
• Dimensions: 265 mm x 220 mm
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• For Use With: AT89S8253

Easy8051 v6 Development System
16.0. Seven-Segment Display
The Easy8051 v6 development system also includes a seven-segment display with four digits that uses the PORT0 and PORT1
microcontroller ports for its operation. Between the PORT0 port and seven-segment display there is a ULN2803 circuit used for
running the segments of the seven-segment display. The operation of such display is enabled by multiplexing, which means that the
operation of all four digits requires only eight lines connected to display segments and four lines for the activation of each digit. The
the operation of the seven-segment display it is necessary to set all switches on the DIP switch SW10 as well as switches 1-4 on the
DIP switch SW8 to the ON position.
The seven-segment display’s time multiplexing is based on fast turning display segments on/off in such a manner that one gets
impression that all digits are active simultaneously. The microcontroller feeds display segments with signals via the PORT0 port,
whereas the PORT1 port selects one of them to display appropriate number. In the example shown in Figure 16-2, signals from the
microcontroller cause the DIS3 display segments to show number 5. When such display is off, the microcontroller sends signal to
the next digit (DIS2), via the P1.2 pin, to show number 6. The same procedure applies to digits DIS1 and DIS0. When one cycle is
complete, another one automatically starts and digits successively change on dislays DIS3, DIS2, DIS1, DIS0, DIS3, DIS2 etc.
Figure 16-2: Showing a digit on the seven-segment display DIS3
Seven-segment digit
Figure 16-1: GLCD display
Red lines mark the signal route from the
microcontroller to the seven-segment display
DIS3 segments.
DIP switch SW10 turns the
seven-segment display
digits on
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