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I need to send RTC data to Seven segment display

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PA3040

PA3040

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Dear all
I need to send RTC data to Seven segment display

RTC data : SEC , MINIS , HOURS , DAY , MONTH , YEAR

I am using 74LS248 IC for BCD to drive seven segment
I am using 4094 IC for mux

I need use single port for both BCD driver and MUX driver ( see image for wiring diagram)

MSB for BCD driver
LSB for MUX driver

can I have algorithm for above program
My MCU is 16f877a + Assembly language
 

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The inputs LT and RBI should be held high and the refresh rate must be at least 120Hz since you have 4 display. Wouldn't it be easier to program it in C?
 

Dear Pretest,

Can you explain it more please

Thanks in advance
 

LT and RBI must be held high to be able to output 0 to 9.

About the refresh rate, since you have 6 independent display the refresh frequency of each display must be at least 30Hz. If you go lower than 30Hz you will see flickering.
 

Dear Pretest,
Thank you very much for reply
I need algorithm for above program, I mean while using same port for BCD data and shift register as per my picture

please advice
 

Here something that could possibly do what you want. I give you pseudo code only.

Read RTC and put the result in a variable.

Select the right display by sending a 0 to your display.
Isolate the value you want to send. Put it on PD0-PD4. Toggle high then low the STB pin of the Mux to latch the enable of your display.

Repeat for each value you need to send.

Hope this helps
 
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