[SOLVED] Displaying last n-digits entered via KEYPAD-PHONE in Proteus

[biedronka]

Hi, I'd really appreciate any kind of advice. I'm currently doing some project where I need to display multiple numbers by pressing keypad phone in Proteus. By the title above, I was thinking of using multiple seven segment displays, where pressing more buttons on the keypad shifts digits from one display to another. Let's think of displaying last 3 entered digits :

1 - 2 - 3

By entering 5, for example, displays're showing the following :

2 - 3 - 5

To accomplish that, I was also thinking of appropriate shift registers. I've done the first part, and by that I mean, displaying one digit on display. I haven't found anything similar to my project. Most of the things I've found include using microcontrollers, but I'm not allowed to use them. That would definitely make this work easier.

Has anyone done anything similar? Is it possible to do this using one multiplexed display in Proteus? I think that my idea's missing something. I don't have that much experience working in Proteus, so, don't mind. Thanks in advance!

 

[KlausST]

Hi,

I don´t want to give a solution. just a hint...

What about using a 4 bit DFF for each digit...

Klaus

 

[biedronka]

Hi,

I don´t want to give a solution. just a hint...

What about using a 4 bit DFF for each digit...

Klaus

Thank you for answering. It has sense, but I'm pretty much confused where exactly to use flipflops here. You see, I have a 4511 component that takes output from MM74C922. I've thought that I have to take its output, and shift it to another 4511 to convert it as an input to some another 7SEG display. By that, it seemed to me that I have to use several 4511 and D flipflops for each 7SEG display to shift previous digits. Sorry if I'm a bit confusing, I'm probably making it more complicated than it is.

 

[KlausST]

Hi,

there are many ways.
so if you want to go with 4 bit DFFs...

then have a critical look to your schematic where there are 4 bits that represent a digit...
That´s the place for the first DFF .. and the others are daisy chained...

Klaus

 

[andre_luis]

In the same way that in programming we sketch the routine in pseudo-code, in circuit design you can draw a general diagram in functional blocks by hand, making it easier to get insights into the options of what to do. It works.

 

[biedronka]

In the same way that in programming we sketch the routine in pseudo-code, in circuit design you can draw a general diagram in functional blocks by hand, making it easier to get insights into the options of what to do. It works.

You're right, it's much practical and also recommended at my Uni when doing bigger projects. Just sometimes I leave it all in my head and wait till it sorts itself And that is mostly because I don't understand some basic stuff good enough and it takes just a little time to get more into.

 

[biedronka]

Hi,

there are many ways.
so if you want to go with 4 bit DFFs...

then have a critical look to your schematic where there are 4 bits that represent a digit...
That´s the place for the first DFF .. and the others are daisy chained...

Klaus

It took some time, but I've finished it, works just like I've imagined. Thank you for understanding and help, my ideas sometimes sound too complicated to me, usually I don't discuss them with anyone. These answers here helped me to take it all easy. Till some next time - bye!

 

[KlausST]

Hi,

the forum is meant that many users can gain useful information from all the the discussions.
Thus it´s expected that you post your solution here.

Klaus