Playing with 64x32 RGB Matrix

If interested, wiring and code is at Instructable

I'm not proud of the code (it's inelegant brute force), but I'm very pleased with how it looks.  Code is on Github.

Circle.h

class Circle {
  public:
    Circle(int x_, int y_, int r_, uint16_t c_);
    int x;
    int y;
    int r;
    uint16_t c;
  private:
};

Circle::Circle(int x_, int y_, int r_, uint16_t c_)
{
  x = x_;
  y = y_;
  r = r_;
  c = c_;
}

 Raindrop.ino

#include <PxMatrix.h>


#ifdef ESP32

#define P_LAT 22
#define P_A 19
#define P_B 23
#define P_C 18
#define P_D 5
#define P_E 15
#define P_OE 2
hw_timer_t * timer = NULL;
portMUX_TYPE timerMux = portMUX_INITIALIZER_UNLOCKED;

#endif

#ifdef ESP8266

#include <Ticker.h>
Ticker display_ticker;
#define P_LAT 16
#define P_A 5
#define P_B 4
#define P_C 15
#define P_D 12
#define P_E 0
#define P_OE 2

#endif
// Pins for LED MATRIX

//PxMATRIX display(32,16,P_LAT, P_OE,P_A,P_B,P_C);
//PxMATRIX display(64,32,P_LAT, P_OE,P_A,P_B,P_C,P_D);
//PxMATRIX display(64,64,P_LAT, P_OE,P_A,P_B,P_C,P_D,P_E);
PxMATRIX display(64, 32, P_LAT, P_OE, P_A, P_B, P_C, P_D, P_E);

//== Circlez ==
int width = 64;
int height = 32;
int xo = width / 2;
int yo = height / 2;
#include "Circle.h"
int dropRate = 500;
unsigned long timeToDrop;
int dropCount = -1;
const int dropMax = 3;
Circle *drops[dropMax];

#ifdef ESP8266
// ISR for display refresh
void display_updater()
{
  //display.displayTestPattern(70);
  display.display(70);
}
#endif

#ifdef ESP32
void IRAM_ATTR display_updater() {
  // Increment the counter and set the time of ISR
  portENTER_CRITICAL_ISR(&timerMux);
  //isplay.display(70);
  display.displayTestPattern(70);
  portEXIT_CRITICAL_ISR(&timerMux);
}
#endif

void InitDrops()
{
  for (int i=0; i<dropMax; i++) {
    drops[i] = new Circle(0,0,0,0);
  }
}

void DropAnother()
{
  if (millis()>timeToDrop) {
    if (++dropCount>=dropMax) dropCount=0;
    Circle *aDrop = drops[dropCount];
    aDrop->x = random(0,width);
    aDrop->y = random(0,height);
    aDrop->r = 1;
    aDrop->c = display.color565(random(8,32), random(8,64), random(8,32));
    timeToDrop = millis() + dropRate;
  }
}

void AnimateCircles()
{
  display.fillScreen(0);
  for (int i=0; i<dropMax; i++) {
    Circle aCircle = *(drops[i]);
    if (aCircle.r != 0) {
      display.drawCircle(aCircle.x, aCircle.y, aCircle.r, aCircle.c);
      drops[i]->r += 1;
    }
  }
  delay(10);
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  display.begin(16);

#ifdef ESP8266
  display_ticker.attach(0.002, display_updater);
#endif

#ifdef ESP32
  timer = timerBegin(0, 80, true);
  timerAttachInterrupt(timer, &display_updater, true);
  timerAlarmWrite(timer, 2000, true);
  timerAlarmEnable(timer);
#endif

  InitDrops();
}

void loop() {
  DropAnother();
  AnimateCircles();
}