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Topic: 74LS259 Latch with Arduino (Read 1 time) previous topic - next topic


Can anyone tell me how to use this latch with Arduino ?


It has a couple of different modes. What are you trying to do with it? 
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


I just want to drive a 7 segment display with it.


Feb 18, 2018, 08:45 am Last Edit: Feb 18, 2018, 08:56 am by GolamMostafa
For what reason (s), do you want to use a 74LS259 Bit Addressable (8-bit) Latch to drive a 7-segment display device when you can directly drive the device using PORTD of the UNO?

Let us look at the MCU burdens to drive only segment-a using PD5 and using 74LS259:

1. Using PD0 bit of PORTD
Code: [Select]
pinMode(5, OUTPUT);
digitalWrite(5, HIGH);                  //segment-a is ON

2. Using 74LS259 Chip
Selection Bits (S2, S1, S0) are connected with: DPins-10, 9, 8
Enable (G/) Bit with : DPin-11
Data Pin (D) with: Dpin-12
Segemnt-1 is connected with Q0-pin of 74LS259

Code: [Select]
DDRB = 0b111111;
PORTB = 0x00;
digitalWrite(12, HIGH);    //Data Bit HIGH

digitalWrite(11, HIGH);    //Enable pulse at G/-pin
digitalWrite(11, LOW);      
digitalWrite(11, HIGH);

Do you still want to use 74LS259? Do you want to exercise the use of double for() loops? If so, then drive the segment pins of a 2-digit multiplexed type display unit using 74LS259 and drive the cc-pins of these devices using 74LS138. Write codes to show 2 an 3 simultaneously on these display devices.


Yes I know how to drive 7segment by using PORTD pins.But I can't use that. could you please tell me how to use 2 multiplexed seven segment display while segment pins are driven with 74LS259 and cc pins are driven by 74LS138


could you please tell me how to use 2
Learning process does not go this way! A learner is always eager, and he tries to do things (good or bad, working or not working does not matter) based on information what he has received in response to his previous requests. You seem to be different! You should do something and post your works with your results.


Actually I was wrong in the 1st place for asking help in this forum. It's useless .

Coding Badly

Actually I was wrong in the 1st place for asking help in this forum.
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Yup.  You definitely picked an inappropriate section for your question.

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