Nesso N1 TFT random display of colors

Official Hardware Kits Nesso N1
1

A simple TFT sketch with randomness, results look like Johnathan Pollack's paintings.

A colored point (seven basic colors; red, yel, grn, cyn, blu, mag, wht, blk) can move in any of nine directions (up, down, left, right, ul, ur, ll, lr, stay), and wraps around screen boundaries, then after 1000 points, changes colors.

#include <Arduino_Nesso_N1.h>  // https://github.com/m5stack/M5GFX/blob/master/src/lgfx/v1/LGFXBase.hpp
NessoDisplay display;

#define h 240
#define w 135

byte i, j, x, y;
int change = 5000, count, color, c, r, g, b;

void setup() {
  Serial.begin(115200);
  display.begin();
  display.fillScreen(TFT_BLACK);
}

void loop() {
  i = random(-1, 2);  // -1, 0, 1
  j = random(-1, 2);
  x += i;
  y += j;

  if (x > w) x = 0;
  if (x < 0) x = w - 1;
  if (y > h) y = 0;
  if (y < 0) y = h - 1;

  if (count++ > change) {
    count = 0;
    if (color++ > 7)
      color = 0;
    r = 31 * bitRead(color, 2);  // 1xx
    g = 63 * bitRead(color, 1);  // x1x
    b = 31 * bitRead(color, 0);  // xx1
    c = r << 11 | g << 5 | b;
  }

  // showvalues();  // debug values
  display.drawPixel(x, y, c);
}

void showvalues() {
  pad(x);
  pad(y);
  pad(r);
  pad(g);
  pad(b);
  pad(c);
  Serial.println();
}

void pad(int val) {
  Serial.print("0x");
  if (val < 0x1000)
    Serial.print("0");
  if (val < 0x100)
    Serial.print("0");
  if (val < 0x10)
    Serial.print("0");
  Serial.print(val, HEX);
  Serial.print(" ");
}