// NanoR3 with array of two independent I2C OLED
// https://forum.arduino.cc/t/nanor3-with-array-of-two-independent-i2c-oled/1417621

#include <avr/wdt.h>  // Include the AVR Watchdog Timer library
#include <U8g2lib.h>
// https://github.com/olikraus/u8g2                    // library
// https://github.com/olikraus/u8g2/wiki/u8g2reference // reference
// https://github.com/olikraus/u8g2/wiki/fntlistall    // fonts

enum: uint8_t {LANDSCAPE1, PORTRAIT1, LANDSCAPE2, PORTRAIT2};

U8G2_SSD1306_128X64_NONAME_F_HW_I2C display[] = { // creates an array of U8G2 objects
  U8G2_SSD1306_128X64_NONAME_F_HW_I2C(U8G2_R0),  // first OLED
  U8G2_SSD1306_128X64_NONAME_F_HW_I2C(U8G2_R0)   // second OLED
};

// U8G2_SSD1306_128X64_NONAME_F_SW_I2C display[] = { // creates an array of U8G2 objects
//   U8G2_SSD1306_128X64_NONAME_F_SW_I2C(U8G2_R0, SCL, SDA, U8X8_PIN_NONE),  // first OLED
//   U8G2_SSD1306_128X64_NONAME_F_SW_I2C(U8G2_R0, SCL, SDA, U8X8_PIN_NONE)   // second OLED
// };

void setup() {
  // Enable the Watchdog Timer with a 1-second timeout
  wdt_enable(WDTO_1S);  // Options: WDTO_15MS, WDTO_30MS, WDTO_60MS, WDTO_120MS, WDTO_250MS, WDTO_500MS, WDTO_1S, WDTO_2S, WDTO_4S, WDTO_8S

  configOled(0, 0x7A, u8g2_font_squeezed_b7_tr);  // address 0x7A is 0x3C in u8g2
  configOled(1, 0x78, u8g2_font_t0_14b_mf);       // address 0x78 is 0x3D in u8g2

  displayOled(0, 0, 3, LANDSCAPE1, "DISPLAY"); // normal rotation, anchor point at lower-left, character is 7 bits  tall
  displayOled(1, 0, 0, PORTRAIT1, "Display"); // rotated clockwise, anchor point is lower-left of character
}

void loop() {
  // Reset the Watchdog Timer to prevent system reset
  wdt_reset();

  // --- Your main code here ---
  // nothing else of interest here
}

void configOled(int number, int address, const uint8_t* font) {
  display[number].setI2CAddress(address);
  display[number].begin();
  display[number].setFont(font);
  display[number].setDrawColor(1);  // white
  display[number].clearDisplay();
  display[number].clearBuffer();
  display[number].sendBuffer();  // transfer internal memory to the display
}

void displayOled(int number, int x, int y, int dir, const char* text) {
  display[number].setFontDirection(dir);
  // display[number].setDisplayRotation(U8G2_R1); // only works with #defines
  display[number].setCursor(x, y);
  display[number].print(text);
  display[number].print(' ');
  display[number].print(number);
  display[number].sendBuffer();
  display[number].clearBuffer();  // must clear buffer to clear next display
}