16x16 led matrix

[M@X77]

Hi dears, I'm building a 16x16 matrix to realize an italian word clock, I'm trying some ways:
basic: 16x16 matrix but asks 32 lines menaing full 4 8 bit port, big cpu but fast display refresh
second way is similar charlieplexer this asks 17 lines but complex logic not fast display refresh (25-30Hz maybe less)
74HC959 + TPIC6C595N complex and big circuit, little cpu quite fast display refresh  (35-45Hz)

My idea is use timer2 to create diplay timing, but shift registers or charlieplex take long code and time to execute it, adding 10 steps brightness control the matrix refresh became slow, my fear is flicker or blinking....

On web I found the Holtek's ics like HT16D33A or HT1632D, very useful with constant current led drive, errors check, brightness contol and so on, maybe these are the best solution, unfunatelly for me is very difficult to buy (nothing on web), has someone idea where to buy? Similar products?

Obviusly there are Maxim MAX7129 or MAX6963, but needs always 4 ics and maybe the cheaper shift reagister solution is the best way...

Thanks
see you soon bye
Max

[wild]

use 2 of the following ICs:
https://lcsc.com/product-detail/LED-Display-Drivers_TMShenzhen-Titan-Micro-Elec-TA6932_C113719.html
https://lcsc.com/product-detail/LED-Display-Drivers_GN-Semic-GN6932_C265476.html

available, cheap and effective (on the web you will find some HALF working libraries for Arduino).

not sure, but the attached one should be the one patched to working correctly.....

[Flash50]

MAX7219
8X8, serial connection as many as you want, brightness control, and is cheap.
But for 16x16, needed 4 pieces.

[M@X77]

use 2 of the following ICs:
https://lcsc.com/product-detail/LED-Display-Drivers_TMShenzhen-Titan-Micro-Elec-TA6932_C113719.html
https://lcsc.com/product-detail/LED-Display-Drivers_GN-Semic-GN6932_C265476.html

available, cheap and effective (on the web you will find some HALF working libraries for Arduino).

not sure, but the attached one should be the one patched to working correctly.....

thanks, i didn't know these productors, i'm looking if there a solution for 16x16 matrix


Posted on: January 10, 2022, 09:14:57 09:14 - Automerged
MM5451YV can be a solution? do you think it is possible to do a matrix?

[ero]

İt will be better for you to examine the P10 panel driver system.
If I did this matrix I would use only 8 bit port for driving the 16 lines by diriving 1 and 9 in sme time driving. In this case you should use 2 pcs shift register (74HC595) as 16 bit for first 8 line (1-8) and 2 shift register other 8 lines (9-16). By the way you can control 16x16 easily..
In this system line1 and Line9 will work together, Line2 and Lne10, Line3 and Lne11 line4 and Line12... line 8 and line16 also will work together. The 4 shift register can be connected serially and each time you can give 4 data for two lines which are working together.
The system can work as follows;
- You give column data to two shift register for upper side (line -1) and  column data to other two shift register for lower side (line9)
- Make active the line exit (you can use there ULN2803 controlled by microprocessor),
- wait enough time 500-1000 us
- make passive the line1and line9
- give the data for secondline on upper side and lower side
- make active line2-10, wait 500-1000us.
- make passsive the line.
...
...
- give the data for the line 8 and also for the line of 16 to the shift registers.
- make active the line nr.8 and also line nr. 16
- wait 500-1000us than make passive the line.
I hope you understand  what I mean.
I used this sytem before it was working without any problem.
As you have undertood you will use only 8 bit port for the line control and three pin for the shift registers only.
Ofcourse it will be good idea to use interrupt for driving the matrix.


Ero

[M@X77]

İt will be better for you to examine the P10 panel driver system.
If I did this matrix I would use only 8 bit port for driving the 16 lines by diriving 1 and 9 in sme time driving. In this case you should use 2 pcs shift register (74HC595) as 16 bit for first 8 line (1-8) and 2 shift register other 8 lines (9-16). By the way you can control 16x16 easily..
In this system line1 and Line9 will work together, Line2 and Lne10, Line3 and Lne11 line4 and Line12... line 8 and line16 also will work together. The 4 shift register can be connected serially and each time you can give 4 data for two lines which are working together.
The system can work as follows;
- You give column data to two shift register for upper side (line -1) and  column data to other two shift register for lower side (line9)
- Make active the line exit (you can use there ULN2803 controlled by microprocessor),
- wait enough time 500-1000 us
- make passive the line1and line9
- give the data for secondline on upper side and lower side
- make active line2-10, wait 500-1000us.
- make passsive the line.
...
...
- give the data for the line 8 and also for the line of 16 to the shift registers.
- make active the line nr.8 and also line nr. 16
- wait 500-1000us than make passive the line.
I hope you understand  what I mean.
I used this sytem before it was working without any problem.
As you have undertood you will use only 8 bit port for the line control and three pin for the shift registers only.
Ofcourse it will be good idea to use interrupt for driving the matrix.


Ero

Yes, this is my third solution, 74HC959 + TPIC6C595N, first two are to pilot anode of grid (6mA for leds) the second are also shift register but open drain and can drive up to 150mA for output and collect matrix's cathodes, I send data to register separatly to speed data sending...

[FTL]

I don't know if you need to use a certain LED panel or not, but if I were you, I would seriously look at using WS2812 type full-color LED's in an array. They can be purchased already in 16 x 16 arrays, or you can make them up yourself.

For instance: https://www.aliexpress.com/item/4000544584524.html

The WS2812's only need 5V, and a single I/O line from the microcontroller. There are several good libraries that make manipulating them easy.

[Thiru09]

This is panel only and cannot be used in MATRIX.

[M@X77]

I don't know if you need to use a certain LED panel or not, but if I were you, I would seriously look at using WS2812 type full-color LED's in an array. They can be purchased already in 16 x 16 arrays, or you can make them up yourself.

For instance: https://www.aliexpress.com/item/4000544584524.html

The WS2812's only need 5V, and a single I/O line from the microcontroller. There are several good libraries that make manipulating them easy.

i know ws2812 but my idea is little, with 1.8mm led or better smd 2835

[FTL]

That makes sense.

How about another off the wall idea:

You are looking at a display that is less than 30mm x 30mm. Could you consider a small OLED display? They are available is that sort of size quite cheaply with 64x64 pixels or so. They are available as both full color and monochrome. If you drive blocks of 4x4 pixels, you would then achieve an effective  16x16 led array that is easy to build and drive.

[M@X77]

oled display is not the same, the idea is drive a led matrix...

[top202]

The WS2812B devices can be strung together into a multi-colour matrix of any, practical, size.

I've done it myself for the Positron8 BASIC compiler using an 18F devices and three wires to the 16x16 matrix display panel. :-) They take quite a lot of current when operating, but are wonderful to watch.

Here's a link to one on Ebay, but there are many available at a lot less price. Or buy some strips of WS2812B devices and wire them as a matrix yourself. It's very straightforward to do.

https://www.ebay.co.uk/itm/222391255403?hash=item33c78d416b:g:edsAAOSwn5pgQLrI

Posted on: January 20, 2022, 05:44:42 17:44 - Automerged
For pixels that imitate small RGB LEDs, use an OLED display and make each LED a multiple of pixels. An OLED is made from LEDs, so the display will look the same.