4 digits 7segment display

[mohannad100]

lfd5522-10

hi
i need to interface 4digits 7 segment display with microcontroller 8051 this segment has 12pin
i serached the web but i cannot find what i need
i need the correct interfacing an programming with 8051
did i need additional circuit for interfacing between 8051 and 4 dugits 7 sgment display.

 

[XNOX_Rambo]

12pin segment

https://www.google.com/search?hl=en&q=4+digits+7+segment+display&btnG=Google+Search

 

[mohannad100]

what is this replay

 

[blueroomelectronics]

Google is your friend

 

[mohannad100]

i have this circuit but it si not what i want because my 4digits 7 segment have 12pin only located below
the entire digits.
and this is it is type LFD5522-10/sp10-1

 

[jit_singh_tara]

hi mohannad , as you said that it has 12 pins then , 8 pins are for data and 4 for common cathode / anode of 4 segments.

the diagram posted above your thread is right if you look at it carefully you will see the data pins of seven segments are common for all four a,b,c,d,e,f,g,dp .

the common pin 3rd of each seven segment is connected to 4 different pins of controller.

therefore 8 pins for data and 4 for enable(or you can say common cathode)makes 12 .

i hope you got the point .

 

[XNOX_Rambo]

It also helps to check the datasheet: **broken link removed**

 

[mohannad100]

i have 12 pin my question is every segment gets 3pin,and if the pin is arranged from left ot right 123-123-123-123
now i need the connection ,is pin3 for every segment connected to transistor and then to port
and the remainning 8 is connected to another port
but i want just to use port1,not two ports,what i should do with common cathod pin
i need the connection
i ait for replay

Added after 7 seconds:

i have 12 pin my question is every segment gets 3pin,and if the pin is arranged from left ot right 123-123-123-123
now i need the connection ,is pin3 for every segment connected to transistor and then to port
and the remainning 8 is connected to another port
but i want just to use port1,not two ports,what i should do with common cathod pin
i need the connection
i wait for replay

 

[jit_singh_tara]

what do you mean by : every segment gets 3 pins ?, every segment needs 8 pins from controller as data if you are using it directly from a full 8 bit port of controller. please clarify your point of " every segment gets 3 pins"....

Added after 4 minutes:

listen man , every segment needs 8 pins from controller as data and one pin for common cathode . this is the thumb rule .
if you have 4 seven degments then all these data pins are shorted with each other .look in the figure.


dont just divide 12/4 = 3 for each segment in your case , it is not like that , first you should know how a seven segment works....

tell me your doubt....i am sure you havent interfaced a single seven segment before....

 

[blueroomelectronics]

You'll need to read the displays datasheet.

 

[mohannad100]

i read the datasheet and i know what i m talking about
i need the multiplexing method of 12 pin to 8051
ok!!!!!

 

[XNOX_Rambo]

It's obvious from blueroomelectronics' schematics. 12 pins are connected to the display.
The segment letters are given in the schematics.
The segment connections are also given in the datasheet.
What is your problem, dude?

 

[blueroomelectronics]

i read the datasheet and i know what i m talking about
i need the multiplexing method of 12 pin to 8051
ok!!!!!

The segments are all connected internally the columns are driven by transistors. Look carefully at the schematic and you'll see only 12 I/O lines are used.

PS it's doubtful you know what you're talking about or you wouldn't be confused.

 

[mohannad100]

hi again
my 4 digits 7 segment is look like the below figure
i need the interface with 8051.
thanks.

 

[jit_singh_tara]

why dont you understand man that 8 data lines are all shorted internally to 4 seven segments , the remaining 4 pins are for selecting individual segment , you continuously change data and select segment 1 , then change data and select segment 2,....similarly all four , the data will change at such a small intervel that human eye will see it as if being displayed statically but in actual the data is changed every time and segment is selected 4 different times resp ... i hope you will uinderstand now....

 

[rajudp]

you are using led module which is having all same pins conntected together expect the common ie pin 1 to 1 .
you can use the same circuit as blueroomelectronics

 

[mohannad100]

thanks