View Full Version : Cascading max7219 ... need help!

05-08-2006, 08:01 PM
Hello, I’m new to the BS, and I need some help...
I’m trying to cascade several max7219 (3 to 6), each of them connected to a dot matrix 5*7 displays, or led array. I have read all the topics from this forum about the max7219, but I don’t find any exact information about how to Crawl Characters horizontally from one dot matrix to another, so that it ‘project text’ (Slogans, phrases, just like in a commercial common led display.)
I also don’t find any code examples on how to flash different Characters in different dot matrix displays at the same time.

Two ‘easy’ examples of code for my application will be:
I want an “A” to go from dot matrix display 1 to 2 to 3 ….
I want an “A” in dot matrix display 1, a “B” in dot matrix display 2, a “C” in dot matrix display 3 ….
Could anyone, send me code examples for these applications?.

I took the Nuts & Volts – 70 - February 2000, and connect the BSII and the max7219 as in the schematics. Then I ‘clean’ Jon’s code for my purpose (see the attached code.bs2), and finally I connect the
Clock and load pins together, and the DIN’s and DOUT’s correctly, like in the maxim documentation. (see the attached image.jpg)
The result is that it Crawl the same Characters horizontally in all the displays. You can watch this video to see what I mean.
Of course, what I will like to do is to Crawl Characters horizontally from one dot matrix to another, so that I can ‘project’ text to be read. In other words, I will like to know how to Crawl Characters between several displays, and how to display Characters separately, each one controlled by a max7219 connected in a chain to the BS.

I don’t know if I’m being clear; if I’m not, please tell me. I’m sorry, but I’m not English speaking.
Thank you, http://forums.parallax.com/images/smilies/roll.gif

Post Edited (felix) : 5/8/2006 1:11:27 PM GMT