LED Matrix With Custom Dimensions

Other Hardware LEDs and Multiplexing
1

Hi everyone I'm new to the forum so go easy!

I'm starting my first arduino project - a digital clock - and looking at the design I'll be needing to make an LED matrix with 10 rows and 11 columns (10x11)

What would be the best way to control them - shift registers? If so, anyone have any suggestions as to which ones to buy?

I've come across many tutorials/sites on 8x8, or 16x16 and similar variations but none discuss the challenges involved with custom matrix dimensions so any help would be appreciated!

Cheers :slight_smile:

2

Chips like the MAX7219 are capable of driving 64 single colour LED's (8x8 matrix) each and you can daisy chain several MAX7219 chips together but you don't need to connect all the LED's. You could just wire them up so 4 chips do 10x11 instead of 16x16.

3

Geee:
I've come across many tutorials/sites on 8x8, or 16x16 and similar variations but none discuss the challenges involved with custom matrix dimensions so any help would be appreciated!

10x11 is just a subset of 16x16...

4

Yes, shift registers.
Simplest: drive 10 rows direct from arduino outputs, sink 200mA current from 11 rows with two TPIC6B595.
Slightly more complex: drive 10 rows from 2 74AC164 shift registers, sink 200mA current from 11 rows with two TPIC6B595.
http://www.digikey.com/product-detail/en/CD74AC164E/296-4235-5-ND/375630
http://www.digikey.com/product-detail/en/TPIC6B595N/296-1956-5-ND/277601
Use current limit resistors between 74AC164 and LED anodes to limit current to 20mA.
Use PWM on TPIC6B595 for brightness control.

Could also use just 2 MAX7219 to control up to 128 LEDs. It does all the multiplexing for you, so you only need to send data to 16 registers.

5

Thanks for the quick replies everyone!

Now to pull the finger out and design a circuit!

:smiley: