Add a simpler helloworld example

[zoobab]

Hi,

I am trying out this simple helloworld code:

https://techtutorialsx.com/2017/12/02/esp32-arduino-interacting-with-a-ssd1306-oled-display/

Would it be possible to add such example to your repo?

Best

[echelon75]

Hi,

Here is a single demo code:
`// Classic Munching Squares effect.

// #include <Wire.h> // Only needed for Arduino 1.6.5 and earlier
#include "SSD1306.h" // alias for #include "SSD1306Wire.h"

//OLED pins to ESP32 GPIOs via this connecthin:
//OLED_SDA -- GPIO4
//OLED_SCL -- GPIO15
//OLED_RST -- GPIO16

SSD1306 display(0x3c, 4, 15);

const unsigned int WIDTH = 128;
const unsigned int HEIGHT = 64;

// 128x64 display
unsigned char image[WIDTH*HEIGHT/8];

void munching(unsigned char t) {
for (int i = 0; i < WIDTH/8; i++) {
for (int j = 0; j < HEIGHT; j++) {
const unsigned int idx = j*(WIDTH/8) + i;
unsigned char c = 0x0;
for (int k = 0; k < 8; k++) {
const unsigned int y = j;
const unsigned int x = (i*8)+k;
if ((x^y) < t) {
c |= (1<<(7-k));
}
}
image[idx]=c;
}
}
}

void setup() {
pinMode(16,OUTPUT);
digitalWrite(16, LOW); // set GPIO16 low to reset OLED
delay(50);
digitalWrite(16, HIGH); // while OLED is running, must set GPIO16 in high

Serial.begin(115200);
Serial.println();
Serial.println();

display.init();

display.flipScreenVertically();
display.displayOn();
display.init();
}

unsigned char t = 0;

void loop() {
munching(t);
t++;
if (t > 128) t = 0;
display.clear();
// display.drawXbm(0,0,128,64,(const char*)image);
// If you receive an error during compilation :
// My_SSD1306_On_TTGO_Oled:59:48: error: invalid conversion from 'const char*' to 'const uint8_t* {aka const unsigned char*}' [-fpermissive]
// display.drawXbm(0,0,128,64,(const char*)image);
// uncomment this line herafter
display.drawXbm(0,0,128,64,(const uint8_t*)image);
// Swap over to get an interleaved munching squares :)
//display.drawFastImage(0,0,128,64,(const char*)image);
display.display();
delay(2);
}`

Regards

Richard