Digital Clock Using 7 Segment Multiplexing
Category: AT89C51
Designer: RANA MUHAMMAD ADNAN KHALIL
Notes
The circuit is designed and simulated in Proteus 7.10 while firmware (c program) is developed in KEIL. This is one of the application of embedded circuit. 1. In this circuit you will learn multiplexing of 7 segments. 2. Concept of a clock will be developed. 3. The important point is to calculate or estimate the delay of 1 second. The accuracy of the clock will depend on the delay of 1 second. 4. The binary to bcd and bcd to 7 segment conversion is directly made in the c program and it is hard coded in lookup table. 5. Port 3 is used for 7 segment data and Port 2 is used for selecting the desired 7 segment. 6. The most important point in multiplexing of 7 segment is the refresh rate. 7. Human eye can detect 17Hz frequency, therefore refresh rate should be greater than or equal to 30Hz. 8. You can download the program and adjust the delay if needed. More circuits of AT89C51 will be added soon.