Help with 4x7 Segment

Hey, just received my 4x7 segment led and was wondering how to display what I want on it using shift register(s).

I cannot find any information on it.


There's a datasheet right there at the link you posted. That should be all the info you need. Have you looked there already or do you need some help?

As the dataheet explains, each segment on the 4 numbers are connected together as common cathodes. That means that when you tun on one, if you have all the other numbers on at the same time they will show the same thing.

To show different numbers on each 'number' then you need to PWM through the anodes so that each LED is being turned on in turn faster than the human eye can see, so it looks like static numbers.


Hi, the display will work with a MAX7219 or MAX7221. A lot of info on this is here :


Using a MAX7219 or MAX7221 is not necessary though as there are enough pins on the arduino to control it...


This guy built an LED clock using a similar 4x7 segment display. You (and I) might be able to use some of the information here to get the display connected and working.

Thanks for all of the replies guys!

I'm looking at PaulS's link currently to try to get this working.

Paul, if you find anything, please let me know!

Ok, I have been messing around with and without the shift register, I cannot get this thing working correctly.

Help please :P

What have you tried? Circuit diagrams etc.

I would first recommend trying to control it without the shift register...


Still can't get it :(

I think better use BCD to 7 segment decoder 4511
so you can convert from bcd to 7 segment and then you can control the cathode of each 7 segment
Here is the schematic diagram 4511