Arduino Forum

Using Arduino => LEDs and Multiplexing => Topic started by: piticasgabriel on Jan 30, 2011, 07:19 pm

Title: arduino big LED matrix with MAX7219s or 74HC595s
Post by: piticasgabriel on Jan 30, 2011, 07:19 pm
Hello All!

I hope someone will help me in this new forum! My school require me to build a 32x8 (or biger) matrix LED display, a single color, to display animations, clock and date (with DS1307), indoor and outdoor temperature (with 2 digital sensors DS18B20), humidity (with SYH-1 sensor), EEPROM 24LC256, switches or encoder etc... I prefer to use  MAX7219 but I think they will accept and 74HC595 in project ... Someone has done something? Or something similar? I need the code, please!

Thank you!

Title: Re: arduino big LED matrix with MAX7219s or 74HC595s
Post by: JanD on Jan 30, 2011, 07:44 pm
http://arduino.cc/playground/Main/LedControl (http://arduino.cc/playground/Main/LedControl) a library to use with MAX7221/MAX7219. With this you can easily drive all leds.
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1191209057/0 (http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1191209057/0) a library to use with DS1307.
http://www.ogalik.ee/node/23 (http://www.ogalik.ee/node/23) setup and link to a library to read from DS18B20 temperature sensors.
Couldn't find a library for the SYH-1 :(
http://10kohms.com/arduino-external-eeprom-24lc256 (http://10kohms.com/arduino-external-eeprom-24lc256) tutorial on how to use the 24LC256 with arduino.
http://www.arduino.cc/playground/Main/RotaryEncoders (http://www.arduino.cc/playground/Main/RotaryEncoders) a tutorial on how to use encoders with arduino.
http://www.arduino.cc/playground/Code/Bounce (http://www.arduino.cc/playground/Code/Bounce) a library for debouncing buttons.

So, I think you are going to go through these links for some time. Then you're done I think you have some ideas.

Jan

P.S. If you are going to use all the above things I think you are going to need to use an Arduino Mega or Sanguino. Not only because of the code, even because you are going to need "some" pins.
Title: Re: arduino big LED matrix with MAX7219s or 74HC595s
Post by: gilmoret on Jan 30, 2011, 11:40 pm
Take a look at these boards from Sure Electronics. Many users have used these on this forum so a good search for code should not be too hard and can be used with any micro-controller including the Arduino.

http://www.sureelectronics.net/category.php?id=60
Title: Re: arduino big LED matrix with MAX7219s or 74HC595s
Post by: piticasgabriel on Jan 31, 2011, 06:50 pm
   Hello and thanks a lot Jan and Tim!!!

Hopefully someone can help me with some code similar to what I need ... I don't have time to learn to program well in Java, to combine and to modify some codes. After school, I work until late at night ... This is something normal in Romania. My school require 5mm LED array with 1 cm distance between LEDs, custom made with hi-bright general purpose clear LEDs. The matrix from Sure have 3mm LEDs.

Thank you again!

Title: Re: arduino big LED matrix with MAX7219s or 74HC595s
Post by: JanD on Jan 31, 2011, 07:30 pm

   Hello and thanks a lot Jan and Tim!!!

Hopefully someone can help me with some code similar to what I need ... I don't have time to learn to program well in Java, to combine and to modify some codes. After school, I work until late at night ... This is something normal in Romania. My school require 5mm LED array with 1 cm distance between LEDs, custom made with hi-bright general purpose clear LEDs. The matrix from Sure have 3mm LEDs.

Thank you again!



1. Arduinos are programmed in a C/C++ like language, not Java.
2. Help? I think this forum is the best you can find for that.
3. A custom LED matrix, huh? What's going to make things harder. But 32x8 = 256 LEDs = 4 MAX7219/MAX7221.

This is going to be an interesting project, and I can almost guaranty you what you are going make it. It will not be too easy but as sad, completely doable.

Jan
Title: Re: arduino big LED matrix with MAX7219s or 74HC595s
Post by: gilmoret on Feb 05, 2011, 04:10 pm
Piticasgabriel,

The link I posted before was to show you the many types of displays that Sure Electronics have some in just 3 mm LEDs and others in both 3 mm LEDs and 5 mm LEDs.

Currently I have 4 working displays and hope to have 8 of them working together of their 5 mm type for the 3216 RG displays by Sure Electronics.

http://www.sureelectronics.net/goods.php?id=1122

You really want to utilize premade LED matrix modules with LED driver chips already installed and ready to just connect up to a micro-controller like an Arduino. If you must design your own LED display board with a custom printed circuit board and individual LEDs, it will be very time consuming and expensive.

Let us know if you have any other questions or require further details.
Title: Re: arduino big LED matrix with MAX7219s or 74HC595s
Post by: piticasgabriel on Mar 20, 2011, 12:02 pm
Hi!
   Finaly, I will insist with MAX7219 because is easy to find/import in Romania, is not very expensive and is a great chip. And I prefer to make a hard job for a great satisfaction!

I observe that many avoid using more than one MAX7219 and I don't understand why?

Awaiting your opinions and suggestions!
Title: Re: arduino big LED matrix with MAX7219s or 74HC595s
Post by: florinc on Mar 21, 2011, 02:36 am
A 595 shift register is almost 10 times cheaper than MAX7219. You will need either one of these chips for each 8x8 single color LED matrix. Therefore, for a 8x32 LED matrix, you will need either 4 x 595 (plus an ULN2803) or 4 x MAX7219.
MAX7219 can be daisy-chained, according to the data sheet.