Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Dot matrix led display

Status
Not open for further replies.

Vonn

Full Member level 4
Joined
Oct 6, 2002
Messages
230
Helped
3
Reputation
6
Reaction score
1
Trophy points
1,298
Activity points
2,460
spi led dot matrix

Hi all
i am building an dot matrix led display board i think to make it interfaced with pc to enter the text through it ... if you have any idea or suggestion plz let me know :roll:
 

penrico

Full Member level 5
Joined
Aug 28, 2001
Messages
286
Helped
27
Reputation
54
Reaction score
8
Trophy points
1,298
Location
Argentina
Activity points
2,395
atmel current control led

Specify more about what resolution you have, or how many characters you will display, etc.

I think easys way to do it, is using 5x8 led dot array, you must put 16 together, and control it with a few logic and a microcontroler like PIC, to control and comunicate it with a PC using serial port.
 

eYe

Member level 4
Joined
Aug 12, 2001
Messages
79
Helped
5
Reputation
10
Reaction score
4
Trophy points
1,288
Activity points
607
characters shifting in matrix led display

check Dallas/Maxim.
There is a chip from LED Dot Matrix Controller.
You will get easy in programmning
 

braveh4rt

Newbie level 6
Joined
Dec 13, 2002
Messages
11
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Indonesia
Activity points
8
rolling display

why not to use ATMEL Controller....

to interfaced with pc use maxim 232 chip and the atmel chip is atc89c52
 

algilsan

Advanced Member level 4
Joined
Jan 20, 2002
Messages
116
Helped
7
Reputation
14
Reaction score
6
Trophy points
1,298
Location
chile
Activity points
1,078
atc89c52

i have worked in led based pannels factory, so ask everything you want, but be a bit detailed.

regards
 

year

Member level 3
Joined
Feb 21, 2002
Messages
62
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
441
mblock.com.tw

You may know as follows

- Constant Current Control for obtaining good brightness

- Dynamic Drive or Static Drive to make suitable system

- Understanding of FONT structure
 

Vonn

Full Member level 4
Joined
Oct 6, 2002
Messages
230
Helped
3
Reputation
6
Reaction score
1
Trophy points
1,298
Activity points
2,460
matrix led display controller ic

i want to display a line of 10 characters with resolution 5 x 8 . with refresh " raster " tech. (dynamic driver)
 

year

Member level 3
Joined
Feb 21, 2002
Messages
62
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
441
maxim dot matrix

You have to consider where it is used !!!
Dynamic drive can not give you Brightness or Luminance.
It is real poblem in field with dynamic drive. Out-door is very dangeous for this reason.
In detail, This system will be 50digit * 8bit. As a result, brightness is 1/50
Circuit is very simple 50 digit is consist of shit register or F/F 8 bit is direct I/O port or latch with array TR.
Software side, interupt routine refresh one digit. Main loop will access(write) display buffer(50 bytes).
 

fatkiller

Junior Member level 1
Joined
Sep 25, 2002
Messages
17
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
64
spi matrix led driver

Hi,

I join 3 Exemples form ELEKTOR revue (french & English).

The X02-2000.prf = With COP8782 MCU: 2 Modules:
1) Keyboard (PS2) directly connected and sending (in IR) to display module.
2) Display module wthit 7 dot led (5*7) dsplay.

The X03-2000.pdf its exemple with 7 segment display

The X06-2001.pdf with 89C4051 mcu and 6 dot led (5*7) display connected to rs232, it's possibe to chain multiple module (max 15). I have tested this, wotks correctely just a small problem of refresh rate with the upper caracter.

Bye
Fatkiller
The next file on another post, sorry max 4 by post.
Ps: F=French E= English
 

algilsan

Advanced Member level 4
Joined
Jan 20, 2002
Messages
116
Helped
7
Reputation
14
Reaction score
6
Trophy points
1,298
Location
chile
Activity points
1,078
Hello,

i have to make a you a question, if you tend to mux 50 bytes per second, like Year said, you probably not be able to view characters with an useful brightness. I should make this thing ,instead:

Make an static driver for one character map, i mean 5 bytes, so i recomend you to use a shit register with latched buffered outputs to drive a single led. The common annode or cathode of this character map will be pass trouwgh a power transistor. Ok! this register will come with CLK, STROBE and BLANK signal. Then BLANK signal is to make brightness control. There are IC in MICREL, MAXIM, with this characteristics, i think they were TPIC or MPIC.

Well once you have this done, you have to join all single Character leds to this outputs. then you will have 10 transistors. So you will have three control signals to control bytes and then control signals to decide what character to display. to make this more easy you can use a shift register for these 10 signals so you only need now two sgnals CLK1 and STROBE1. and that's all, now you mux time are reduced to 1/10 instead 1/50.

regards
 

algilsan

Advanced Member level 4
Joined
Jan 20, 2002
Messages
116
Helped
7
Reputation
14
Reaction score
6
Trophy points
1,298
Location
chile
Activity points
1,078
Sorry for my english. i have to explain something i now in my not native idiom, and it's not very ease for me.

Sorry again
 

pcduong

Newbie level 6
Joined
Dec 3, 2002
Messages
14
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Hanoi, Vietnam
Activity points
38
Hi,
For matrix led display there is a excelent drivers from MAXIM :
MAX7219 or MAX7221.
They use a simple SPI interface to control the led matrix and may be cascaded.
OR you can use the shift register 74HC595 which contains in it self a tristate latch and may be controled using SPI protocol.
 

techie

Advanced Member level 3
Joined
Feb 5, 2002
Messages
839
Helped
58
Reputation
116
Reaction score
9
Trophy points
1,298
Location
Pakistan
Activity points
7,799
Which constant current drive IC is best suited for LED displays? specially for the matrix LED screens used for outdoor applications.
 

bobcat1

Advanced Member level 4
Joined
Jul 10, 2002
Messages
1,288
Helped
99
Reputation
198
Reaction score
34
Trophy points
1,328
Activity points
8,547
use 6276 from alegro

use 6276 from alegro it's 16 bit led driver shift register and it's low cost
$ 1.1 in 1000 qty

if u need singles qty go to nuhorizons.com but it's cost bit higher


bobi
 

techie

Advanced Member level 3
Joined
Feb 5, 2002
Messages
839
Helped
58
Reputation
116
Reaction score
9
Trophy points
1,298
Location
Pakistan
Activity points
7,799
How much does this Chip cost in quantity of 1000 pcs or sso
 

Gomez

Full Member level 2
Joined
Feb 12, 2002
Messages
125
Helped
10
Reputation
20
Reaction score
3
Trophy points
1,298
Activity points
1,006
techie said:
How much does this Chip cost in quantity of 1000 pcs or sso
I have take the MBI5016CP for my application. The price is 0,68USD/1pcs (1700pcs). The MBI5016 is in SSOP. Allegro has't SSOP device.

Shipping is with FedEx and T/T in advance. Whenn you need any support, call
Vivian Chang
Office phone no.:+886-3-5790068~708
vivian@mblock.com.tw

Gomez
 

Gomez

Full Member level 2
Joined
Feb 12, 2002
Messages
125
Helped
10
Reputation
20
Reaction score
3
Trophy points
1,298
Activity points
1,006
braveh4rt said:
why not to use ATMEL Controller....

to interfaced with pc use maxim 232 chip and the atmel chip is atc89c52
For constant current drivers IC for LED you need a controller with SPI. The at89c52 has't SPI.

Gomez
 
Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top