WIKI de Bertrand VANDEPORTAELE

notice: https://cdn-learn.adafruit.com/downloads/pdf/32x16-32x32-rgb-led-matrix.pdf

librairies arduino:

https://github.com/adafruit/RGB-matrix-Panel

https://github.com/adafruit/Adafruit-GFX-Library

mkdir  ~/rgb32
cd ~/rgb32
git clone https://github.com/adafruit/RGB-matrix-Panel.git
git clone https://github.com/adafruit/Adafruit-GFX-Library.git
mv RGB-matrix-Panel ~/sketchbook/libraries/RGBmatrixPanel
mv Adafruit-GFX-Library ~/sketchbook/libraries/Adafruit_GFX

ajouter au début des fichiers d'exemple si besoin

#include <SPI.h>

le programme d'exemple testcolors_16x32 invoque RGBmatrixPanel matrix(A, B, C, CLK, LAT, OE, false); le false est pour l'écran 32×16. en débranchant le fil A3, la broche correspondante sur l'afficheur est en l'air et on a bien les carrés de couleur. en mettant true pour le 32×32, l'affichage foire!

La librairie Adafruit utilise interruption timer + code assembleur pour gérer l'affichage d'un buffer mémoire avec gestion PWM. MAIS CA NE FONTIONNE PAS!!! donc je dois me coltiner la…

ICN2026 pdf me redirige dans http://www.starchips.com.tw/pdf/datasheet/SCT2024V01_03.pdf

Il est dit que le chip supporte 25Mhz de clk

CLK: Clock input of shift register, data is sampled at the rising edge of CLK
LA/ Input terminal of data strobe. Data is latched when LA/ is low. And data on shift register goes through when LA/ is high. 

Chronogrammes en page 5 de http://www.starchips.com.tw/pdf/datasheet/SCT2024V01_03.pdf

Programme ne nécessitant aucune librairie destiné à comprendre les signaux à envoyer à l'afficheur:

test_rgb32_bvdp.ino

 //B. Vandeportaele 2017
//simple program to test 32x32 rgb led panel
 
//pin settings
#define CLK 8 
#define OE  9
#define LAT 10
#define A   A0
#define B   A1
#define C   A2
#define D   A3
 
//B0 is  reserved, so use B_0 instead
#define R_0 (0x01<<2)
#define G_0 (0x01<<3)
#define B_0 (0x01<<4)
#define R_1 (0x01<<5)
#define G_1 (0x01<<6)
#define B_1 (0x01<<7)
 
int CPTx=0; //counters
int CPTy=0;
 
void setup() {
  //port D pins 2-7 drive RGB0 and RGB1 pins
  //set DDRD bits to 1 for outputs
  DDRD |= 0xFC ;
  //set default output values to 1
  PORTD =0xFC;
 
  pinMode(CLK, OUTPUT);
  pinMode(OE, OUTPUT);
  pinMode(LAT, OUTPUT);
  pinMode(A, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
  pinMode(D, OUTPUT);
 
  digitalWrite(CLK, LOW);
  digitalWrite(OE, HIGH);
  digitalWrite(LAT, HIGH);
  digitalWrite(LAT, LOW);  
 
}
 
void loop() {
  //drive the decoder 1 to 16 to select the line
  digitalWrite(A, (CPTy>>0)&1); //lsb
  digitalWrite(B, (CPTy>>1)&1);
  digitalWrite(C, (CPTy>>2)&1);
  digitalWrite(D, (CPTy>>3)&1); //msb
 
  for (CPTx=0;CPTx<4;CPTx++){ // draw four time the same pattern
    PORTD =R_0 | G_0 | B_0 | R_1 | G_1 | B_1 ; //  white on both sides of the pannel
    digitalWrite(CLK, LOW); digitalWrite(CLK, HIGH); //strobe
    PORTD =B_0 |B_1;
    digitalWrite(CLK, LOW); digitalWrite(CLK, HIGH); //strobe
    PORTD =R_0 | R_1;
    digitalWrite(CLK, LOW); digitalWrite(CLK, HIGH); //strobe
    PORTD =G_0 |G_1;
    digitalWrite(CLK, LOW); digitalWrite(CLK, HIGH); //strobe
    PORTD =R_0| G_0 | R_1 |G_1;
    digitalWrite(CLK, LOW); digitalWrite(CLK, HIGH); //strobe
    PORTD =R_0| B_0 | R_1|B_1;
    digitalWrite(CLK, LOW); digitalWrite(CLK, HIGH); //strobe
    PORTD =B_0| G_0 |B_1 |G_1;
    digitalWrite(CLK, LOW); digitalWrite(CLK, HIGH); //strobe
    PORTD =0;
    digitalWrite(CLK, LOW); digitalWrite(CLK, HIGH); //strobe
    }
  //latch
  digitalWrite(LAT, HIGH);
  digitalWrite(LAT, LOW);  
  //activate the display for a certain amount of time
  digitalWrite(OE, LOW);
  delay(1);
  //deactivate the display during the transfer of the next line
  digitalWrite(OE, HIGH);
  CPTy++; //go to the next line
}

Ce programme fonctionne et permet l'affichage de 8 bandes de couleurs différentes répétées 4 fois.

vidéos: https://bvdp.inetdoc.net/files/rgbpanel/V71021-230843.mp4