Dual led question

Thread Starter

u-will-neva-no

Joined Mar 22, 2011
230
Hi everyone, I have a short question based on dual (bi) dot matrix leds. My led dot matrix has 24 pins and has 2 leds (green and red) in each of the 64 segments. All i want to do is wire it so that one led color lights up. So what i have done is not to connect the red pins so that thr green lights up.

Do I have to connect all pins on the led matrix to my IC (which is the Austriamicrosystems chip that produces the same function as the MAX chip).?

Thanks!
 

SgtWookie

Joined Jul 17, 2007
22,210
You have given two manufacturer's names, Austriamicrosystems and Dallas/Maxim (actually, just implied the last) and mentioned that you have a dual (bi)-color dot matrix LED.

We don't know which of their IC's you are talking about.
We don't know if your LED matrix is common cathode, common anode, or if they are connected as cathode-to-anode and anode-to-cathode.

Basically, with the information you've supplied, we can't give you an answer.

Post links to the datasheets for your LED matrix, and the ICs that you are referring to.
 

Thread Starter

u-will-neva-no

Joined Mar 22, 2011
230
I have the AS1107PL and my led matrix is common cathode. I forgot to mention that, sorry. The IC only works with common cathode so there is no issue regarding that. I will post the data sheet on thr next post.
 

SgtWookie

Joined Jul 17, 2007
22,210
The AS1106/AS1107 is an 8-digit 7-segment display driver, and you have an LED matrix, not a 7-segment display.

I don't know how you're planning on connecting them up, but it's not going to work very well.
 

SgtWookie

Joined Jul 17, 2007
22,210
So it does. It would have been easier and faster to answer your question if you had linked to the datasheets when I requested it.

You will need one AS1106/AS1107 per digit, and you will need to connect the matrix as shown in the datasheet on page 16.

And yes, you can just use the one color LED, leaving the pins for the anodes of the non-used LEDs disconnected.
 

Thread Starter

u-will-neva-no

Joined Mar 22, 2011
230
Ah thats good then. I provided the IC circuut from the data sheet thinking that It would be quicker. In future I will attach the data sheet, sorry about that and thanks for replying!
 

John P

Joined Oct 14, 2008
1,808
Anyway, the answer is--if you only want to drive one color, just ignore the pins that supply the other color. And with an array like that, there is no such thing as "common anode" or "common cathode". You drive it as a matrix, where the cathodes go to the appropriate pins of the IC and the anodes, likewise. You will have to figure out what to send to the IC to display any characters you want to see!

Actually maybe it's better to ground the unused pins than just leave them floating. But no current will pass that way.
 
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