Hello everyone !
I come to ask my problem here because on the Velleman forum it’s asleep.
The Arduino forum has always been a great source of inspiration and answers for me.
Thank you in advance for your patience and your help !
I received this product : Velleman VMA419
I have two and I want to scroll through text on both. Same text on one screen but with two matrix.
I control it with an Arduino Uno and the library available of the Velleman website “VMA419_library.zip”.
In fact the VMA419 product is a copy of the Freetronics DMD, the library is proof of that. It is marked “Freetronics” inside.
But the Velleman library is different. They work
fine with the VMA419.
The DMD Freetronics library, it does not work with the VMA419, glitch are present.
My problem: My two panels work, the text scrolls but it is twice the same display.
the line of my code “#define DISPLAYS_ACROSS 2” does not seem to take my two screens.
You will find my code in attachment, I tested it with the library of Velleman and Freetronics.
The Freetronics library shows me a glitchy text but seems to take my two screens. The glitchy “text” scrolls well on my two panels.
I also analyzed the two libraries, is the paragraph on the SPI which is different.
Specifically in the DMD.cpp file.
So, i gathered the differences in the file “SPI dif.pdf”
Thank you the arduino team !
DMD419.cpp (20.3 KB)
DMD.cpp (19.2 KB)
dmd_VMA419_TEXTSCROLL.ino (3.83 KB)
SPI dif.pdf (24.1 KB)