4 digit 7Segment Multiplexing using 8051F330

M

moohoo123

New Member

• Sep 29, 2009

• #1

Hi!
I am currently working on an assignment using 4 thumbwheels to control 4 7 Segments. However, to reduce the number of I/O pins used, i will have to multiplex the 7 segments(Common Cathode).

I am unsure of the codes to used to control each segment. Anyone have any guidelines for me?

Currently using C only.

Thanks

 

blueroomelectronics

Well-Known Member

• Sep 29, 2009

• #2

Which microcontroller are you using. Post your schematic.

 

S

srikanthsamaga

New Member

• Oct 5, 2009

• #3

I have built some circuit and relevant assembly code for multiplexing seven segments...
**broken link removed**

Best of luck

 

Gayan Soyza

Active Member

• Oct 5, 2009

• #4

That is for common anode not for common cathode.

For common cathodes driver transistor (NPN) is need for each display common pin & the data is supplying the possitive path from the micro controller side.Each driver transistor must turn on one at a time & the correct binary pattern must move to the correct place (segment) of each drive transistors position.

 

Last edited: Oct 5, 2009

S

srikanthsamaga

New Member

• Oct 5, 2009

• #5

But working principle is same for both common cathode and anode, the only difference is that the output data should be complimented and transistors should be changed.

 

R

rajbex

Member

• Oct 10, 2009

• #6

I have done multiplexing to interface 4 Seven-Segment Displays to a PIC16F628A using mikroC compiler. Check here: Experiments with PIC16F628A: Experiment No. 5: Multiplexed Seven Segment Displays

Raj