// simple project using Arduino UNO and 128x64 SSD1306 IIC OLED Display to show battery charging indicator

// created by upir, 2023
// youtube channel: https://www.youtube.com/upir_upir

// YOUTUBE VIDEO: https://youtu.be/caHcaUoQ2kg
// SOURCE files: https://github.com/upiir/arduino_oled_battery_indicator

// Links from the video:
// 72x40 SSD1306 OLED 0.42" Display: https://s.click.aliexpress.com/e/_Ddq0EwJ
// 128x64 SSD1306 OLED Display 1.54": https://s.click.aliexpress.com/e/_DCYdWXb 
// 128x64 SSD1306 OLED Display 0.96": https://s.click.aliexpress.com/e/_DCKdvnh
// 128x64 SSD1306 OLED Display 2.42": https://s.click.aliexpress.com/e/_DFdMoTh
// Arduino UNO: https://s.click.aliexpress.com/e/_AXDw1h
// Arduino breadboard prototyping shield: https://s.click.aliexpress.com/e/_ApbCwx
// Image2cpp (convert array to image): https://javl.github.io/image2cpp/
// Photopea (online graphics editor like Photoshop): https://www.photopea.com/

// Related videos with Arduino UNO and 128x64 OLED screen:
// Arduino + OLED displays playlist: https://www.youtube.com/playlist?list=PLjQRaMdk7pBZ1UV3IL5ol8Qc7R9k-kwXA


#include <Arduino.h> 
#include <U8g2lib.h> // u8g2 library used for drawing on the OLED display

#include <Wire.h> // library requires for IIC communication

// I´m using two different displays, 128x64px in the WOKWI emulation and 72x40px for real Arduino
// Please uncomment the correct initialization line and comment out the other one

//U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE); // initialization for the 128x64px display
U8G2_SSD1306_72X40_ER_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);// 72x40px display [full framebuffer, size = 360 bytes]



int battery_fill_perc = 0; // battery fill percentage 0-100%
int anim_frame = 0; // animation frame for the blob / metaballs animation

int xoff = 29;//0;//29;   // x offset for the battery
int yoff = 12;//0;//24;   // y offset for the battery

void setup(void) {
  u8g2.begin();
}

void loop(void) {
	u8g2.clearBuffer();	// clear the internal memory
	u8g2.setBitmapMode(1); // draw transparent images
	u8g2.setFont(u8g2_font_ncenB14_tr);
	u8g2.drawStr(0,15,"Hello World!");
	u8g2.sendBuffer();
  delay(1000);
}

/*
void loop(void) {
  u8g2.clearBuffer();	// clear the internal memory
	u8g2.setBitmapMode(1); // draw transparent images

  u8g2.drawXBMP(xoff, yoff, 70, 40, epd_bitmap_battery_outline); // draw the image of the outline of the battery icon

  int fill_width = map(battery_fill_perc, 0, 100, 4, 61); // width of the fill rectangle
	u8g2.drawRBox(xoff+3, yoff+3, fill_width, 34, 1); // battery fill, rounded filled rectangle

  u8g2.setClipWindow(xoff+3, yoff+3, xoff + 3 + 61, yoff+3 + 34); // restrict all graphics output to the specified range
	u8g2.drawXBMP(xoff + 3 + fill_width - 1, yoff+3, 32, 34, epd_bitmap_allArray[anim_frame]); // draw blob animation
	u8g2.setMaxClipWindow(); // restore writing to the complete window

  //u8g2.drawFrame(29, 24, 70, 40);  // draw fullscreen rectangle - this was only used for testing

  u8g2.sendBuffer();					// transfer internal memory to the display


  // increase battery fill percentage 0-100
	battery_fill_perc++;
	if (battery_fill_perc > 100) {battery_fill_perc = 0;}

  // current frame for the blob animation, 0-29
	anim_frame = (anim_frame + 1) % 30;
}
*/