// Display Library example for SPI e-paper panels from Dalian Good Display and boards from Waveshare.
// Requires HW SPI and Adafruit_GFX. Caution: these e-papers require 3.3V supply AND data lines!
//
// Display Library based on Demo Example from Good Display: http://www.good-display.com/download_list/downloadcategoryid=34&isMode=false.html
//
// Author: Jean-Marc Zingg
//
// Version: see library.properties
//
// Library: https://github.com/ZinggJM/GxEPD2

// GxEPD2_U8G2_Fonts_Example : show use of U8G2_FOR_ADAFRUIT_GFX with GxEPD2
//
// Library: https://github.com/olikraus/U8g2_for_Adafruit_GFX
// see: https://github.com/olikraus/U8g2_for_Adafruit_GFX/blob/master/README.md
//
// NOTE: you need to SAVE the modified example to a saveable location for UTF-8 characters to work
//       e.g. for Umlauts

// Supporting Arduino Forum Topics:
// Waveshare e-paper displays with SPI: http://forum.arduino.cc/index.php?topic=487007.0
// Good Dispay ePaper for Arduino : https://forum.arduino.cc/index.php?topic=436411.0

// mapping suggestion from Waveshare SPI e-Paper to Wemos D1 mini
// BUSY -> D2, RST -> D4, DC -> D3, CS -> D8, CLK -> D5, DIN -> D7, GND -> GND, 3.3V -> 3.3V

// mapping suggestion from Waveshare SPI e-Paper to generic ESP8266
// BUSY -> GPIO4, RST -> GPIO2, DC -> GPIO0, CS -> GPIO15, CLK -> GPIO14, DIN -> GPIO13, GND -> GND, 3.3V -> 3.3V

// mapping of Waveshare e-Paper ESP8266 Driver Board
// BUSY -> GPIO16, RST -> GPIO5, DC -> GPIO4, CS -> GPIO15, CLK -> GPIO14, DIN -> GPIO13, GND -> GND, 3.3V -> 3.3V

// mapping suggestion for ESP32, e.g. LOLIN32, see .../variants/.../pins_arduino.h for your board
// NOTE: there are variants with different pins for SPI ! CHECK SPI PINS OF YOUR BOARD
// BUSY -> 4, RST -> 16, DC -> 17, CS -> SS(5), CLK -> SCK(18), DIN -> MOSI(23), GND -> GND, 3.3V -> 3.3V

// new mapping suggestion for STM32F1, e.g. STM32F103C8T6 "BluePill"
// BUSY -> A1, RST -> A2, DC -> A3, CS-> A4, CLK -> A5, DIN -> A7

// mapping suggestion for AVR, UNO, NANO etc.
// BUSY -> 7, RST -> 9, DC -> 8, CS-> 10, CLK -> 13, DIN -> 11

// base class GxEPD2_GFX can be used to pass references or pointers to the display instance as parameter, uses ~1.2k more code
// enable or disable GxEPD2_GFX base class
#define ENABLE_GxEPD2_GFX 0

#include <GxEPD2_BW.h>
#include <GxEPD2_3C.h>
#include <Fonts/FreeMonoBold9pt7b.h>
#include <U8g2_for_Adafruit_GFX.h>

#if defined (ESP8266)
// select one and adapt to your mapping, can use full buffer size (full HEIGHT)
//GxEPD2_BW<GxEPD2_154, GxEPD2_154::HEIGHT> display(GxEPD2_154(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_BW<GxEPD2_213, GxEPD2_213::HEIGHT> display(GxEPD2_213(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_BW<GxEPD2_290, GxEPD2_290::HEIGHT> display(GxEPD2_290(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_BW<GxEPD2_270, GxEPD2_270::HEIGHT> display(GxEPD2_270(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_BW<GxEPD2_420, GxEPD2_420::HEIGHT> display(GxEPD2_420(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
// can use only half buffer size
//GxEPD2_BW < GxEPD2_583, GxEPD2_583::HEIGHT / 2 > display(GxEPD2_583(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_BW < GxEPD2_750, GxEPD2_750::HEIGHT / 2 > display(GxEPD2_750(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
// 3-color e-papers
//GxEPD2_3C<GxEPD2_154c, GxEPD2_154c::HEIGHT> display(GxEPD2_154c(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_3C<GxEPD2_213c, GxEPD2_213c::HEIGHT> display(GxEPD2_213c(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_3C<GxEPD2_290c, GxEPD2_290c::HEIGHT> display(GxEPD2_290c(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_3C<GxEPD2_270c, GxEPD2_270c::HEIGHT> display(GxEPD2_270c(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
// can use only half buffer size
//GxEPD2_3C<GxEPD2_420c, GxEPD2_420c::HEIGHT / 2> display(GxEPD2_420c(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
// can use only quarter buffer size
//GxEPD2_3C<GxEPD2_583c, GxEPD2_583c::HEIGHT / 4> display(GxEPD2_583c(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));
//GxEPD2_3C<GxEPD2_750c, GxEPD2_750c::HEIGHT / 4> display(GxEPD2_750c(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4));

// ***** for mapping of Waveshare e-Paper ESP8266 Driver Board *****
// select one , can use full buffer size (full HEIGHT)
//GxEPD2_BW<GxEPD2_154, GxEPD2_154::HEIGHT> display(GxEPD2_154(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_BW<GxEPD2_213, GxEPD2_213::HEIGHT> display(GxEPD2_213(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_BW<GxEPD2_290, GxEPD2_290::HEIGHT> display(GxEPD2_290(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_BW<GxEPD2_270, GxEPD2_270::HEIGHT> display(GxEPD2_270(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_BW<GxEPD2_420, GxEPD2_420::HEIGHT> display(GxEPD2_420(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
// can use only half buffer size
//GxEPD2_BW < GxEPD2_583, GxEPD2_583::HEIGHT / 2 > display(GxEPD2_583(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_BW < GxEPD2_750, GxEPD2_750::HEIGHT / 2 > display(GxEPD2_750(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
// 3-color e-papers
//GxEPD2_3C<GxEPD2_154c, GxEPD2_154c::HEIGHT> display(GxEPD2_154c(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_3C<GxEPD2_213c, GxEPD2_213c::HEIGHT> display(GxEPD2_213c(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_3C<GxEPD2_290c, GxEPD2_290c::HEIGHT> display(GxEPD2_290c(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_3C<GxEPD2_270c, GxEPD2_270c::HEIGHT> display(GxEPD2_270c(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
// can use only half buffer size
//GxEPD2_3C<GxEPD2_420c, GxEPD2_420c::HEIGHT / 2> display(GxEPD2_420c(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
// can use only quarter buffer size
//GxEPD2_3C<GxEPD2_583c, GxEPD2_583c::HEIGHT / 4> display(GxEPD2_583c(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
//GxEPD2_3C<GxEPD2_750c, GxEPD2_750c::HEIGHT / 4> display(GxEPD2_750c(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16));
#endif

#if defined(ESP32)
// select one and adapt to your mapping, can use full buffer size (full HEIGHT)
//GxEPD2_BW<GxEPD2_154, GxEPD2_154::HEIGHT> display(GxEPD2_154(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_BW<GxEPD2_213, GxEPD2_213::HEIGHT> display(GxEPD2_213(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_BW<GxEPD2_290, GxEPD2_290::HEIGHT> display(GxEPD2_290(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_BW<GxEPD2_270, GxEPD2_270::HEIGHT> display(GxEPD2_270(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_BW<GxEPD2_420, GxEPD2_420::HEIGHT> display(GxEPD2_420(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_BW<GxEPD2_750, GxEPD2_750::HEIGHT> display(GxEPD2_750(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
// 3-color e-papers
//GxEPD2_3C<GxEPD2_154c, GxEPD2_154c::HEIGHT> display(GxEPD2_154c(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_3C<GxEPD2_213c, GxEPD2_213c::HEIGHT> display(GxEPD2_213c(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_3C<GxEPD2_290c, GxEPD2_290c::HEIGHT> display(GxEPD2_290c(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_3C<GxEPD2_270c, GxEPD2_270c::HEIGHT> display(GxEPD2_270c(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_3C<GxEPD2_420c, GxEPD2_420c::HEIGHT> display(GxEPD2_420c(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
//GxEPD2_3C<GxEPD2_750c, GxEPD2_750c::HEIGHT> display(GxEPD2_750c(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4));
#endif

#if defined(_BOARD_GENERIC_STM32F103C_H_)
#define MAX_DISPAY_BUFFER_SIZE 15000ul // ~15k is a good compromise
#define MAX_HEIGHT(EPD) (EPD::HEIGHT <= MAX_DISPAY_BUFFER_SIZE / (EPD::WIDTH / 8) ? EPD::HEIGHT : MAX_DISPAY_BUFFER_SIZE / (EPD::WIDTH / 8))
// select one and adapt to your mapping
//GxEPD2_BW<GxEPD2_154, MAX_HEIGHT(GxEPD2_154)> display(GxEPD2_154(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_BW<GxEPD2_213, MAX_HEIGHT(GxEPD2_213)> display(GxEPD2_213(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_BW<GxEPD2_290, MAX_HEIGHT(GxEPD2_290)> display(GxEPD2_290(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_BW<GxEPD2_270, MAX_HEIGHT(GxEPD2_270)> display(GxEPD2_270(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_BW<GxEPD2_420, MAX_HEIGHT(GxEPD2_420)> display(GxEPD2_420(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_BW<GxEPD2_583, MAX_HEIGHT(GxEPD2_583)> display(GxEPD2_583(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_BW<GxEPD2_750, MAX_HEIGHT(GxEPD2_750)> display(GxEPD2_750(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
// 3-color e-papers
#define MAX_HEIGHT_3C(EPD) (EPD::HEIGHT <= (MAX_DISPAY_BUFFER_SIZE / 2) / (EPD::WIDTH / 8) ? EPD::HEIGHT : (MAX_DISPAY_BUFFER_SIZE / 2) / (EPD::WIDTH / 8))
//GxEPD2_3C<GxEPD2_154c, MAX_HEIGHT_3C(GxEPD2_154c)> display(GxEPD2_154c(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_3C<GxEPD2_213c, MAX_HEIGHT_3C(GxEPD2_213c)> display(GxEPD2_213c(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_3C<GxEPD2_290c, MAX_HEIGHT_3C(GxEPD2_290c)> display(GxEPD2_290c(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_3C<GxEPD2_270c, MAX_HEIGHT_3C(GxEPD2_270c)> display(GxEPD2_270c(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_3C<GxEPD2_420c, MAX_HEIGHT_3C(GxEPD2_420c)> display(GxEPD2_420c(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_3C<GxEPD2_583c, MAX_HEIGHT_3C(GxEPD2_583c)> display(GxEPD2_583c(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
//GxEPD2_3C<GxEPD2_750c, MAX_HEIGHT_3C(GxEPD2_750c)> display(GxEPD2_750c(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1));
#endif

#if defined(__AVR)
#define MAX_DISPAY_BUFFER_SIZE 800 // 
#define MAX_HEIGHT(EPD) (EPD::HEIGHT <= MAX_DISPAY_BUFFER_SIZE / (EPD::WIDTH / 8) ? EPD::HEIGHT : MAX_DISPAY_BUFFER_SIZE / (EPD::WIDTH / 8))
// select one and adapt to your mapping
//GxEPD2_BW<GxEPD2_154, MAX_HEIGHT(GxEPD2_154)> display(GxEPD2_154(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_BW<GxEPD2_213, MAX_HEIGHT(GxEPD2_213)> display(GxEPD2_213(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_BW<GxEPD2_290, MAX_HEIGHT(GxEPD2_290)> display(GxEPD2_290(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_BW<GxEPD2_270, MAX_HEIGHT(GxEPD2_270)> display(GxEPD2_270(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_BW<GxEPD2_420, MAX_HEIGHT(GxEPD2_420)> display(GxEPD2_420(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_BW<GxEPD2_583, MAX_HEIGHT(GxEPD2_583)> display(GxEPD2_583(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_BW<GxEPD2_750, MAX_HEIGHT(GxEPD2_750)> display(GxEPD2_750(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
// 3-color e-papers
#define MAX_HEIGHT_3C(EPD) (EPD::HEIGHT <= (MAX_DISPAY_BUFFER_SIZE / 2) / (EPD::WIDTH / 8) ? EPD::HEIGHT : (MAX_DISPAY_BUFFER_SIZE / 2) / (EPD::WIDTH / 8))
//GxEPD2_3C<GxEPD2_154c, MAX_HEIGHT_3C(GxEPD2_154c)> display(GxEPD2_154c(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_3C<GxEPD2_213c, MAX_HEIGHT_3C(GxEPD2_213c)> display(GxEPD2_213c(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_3C<GxEPD2_290c, MAX_HEIGHT_3C(GxEPD2_290c)> display(GxEPD2_290c(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_3C<GxEPD2_270c, MAX_HEIGHT_3C(GxEPD2_270c)> display(GxEPD2_270c(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_3C<GxEPD2_420c, MAX_HEIGHT_3C(GxEPD2_420c)> display(GxEPD2_420c(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_3C<GxEPD2_583c, MAX_HEIGHT_3C(GxEPD2_583c)> display(GxEPD2_583c(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
//GxEPD2_3C<GxEPD2_750c, MAX_HEIGHT_3C(GxEPD2_750c)> display(GxEPD2_750c(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
#endif

#include "GxEPD2_boards_added.h"

U8G2_FOR_ADAFRUIT_GFX u8g2Fonts;

void setup()
{
  Serial.begin(115200);
  Serial.println();
  Serial.println("setup");
  display.init();
  u8g2Fonts.begin(display); // connect u8g2 procedures to Adafruit GFX
  helloWorld();
  delay(1000);
  helloArduino();
  delay(1000);
  helloEpaper();
  delay(1000);
  showFont("u8g2_font_helvR14_tf", u8g2_font_helvR14_tf); // select u8g2 font from here: https://github.com/olikraus/u8g2/wiki/fntlistall
  delay(2000);
  showFont("u8g2_font_profont22_mr", u8g2_font_profont22_mr); // select u8g2 font from here: https://github.com/olikraus/u8g2/wiki/fntlistall
  delay(1000);
  Serial.println("setup done");
}

void loop()
{
}

void helloWorld()
{
  //Serial.println("helloWorld");
  uint16_t bg = GxEPD_WHITE;
  uint16_t fg = GxEPD_BLACK;
  u8g2Fonts.setFontMode(1);                 // use u8g2 transparent mode (this is default)
  u8g2Fonts.setFontDirection(0);            // left to right (this is default)
  u8g2Fonts.setForegroundColor(fg);         // apply Adafruit GFX color
  u8g2Fonts.setBackgroundColor(bg);         // apply Adafruit GFX color
  u8g2Fonts.setFont(u8g2_font_helvR14_tf);  // select u8g2 font from here: https://github.com/olikraus/u8g2/wiki/fntlistall
  uint16_t x = (display.width() - 160) / 2;
  uint16_t y = display.height() / 2;
  display.firstPage();
  do
  {
    display.fillScreen(bg);
    u8g2Fonts.setCursor(x, y); // start writing at this position
    u8g2Fonts.print("Hello World!");
  }
  while (display.nextPage());
  //Serial.println("helloWorld done");
}

void helloArduino()
{
  //Serial.println("helloArduino");
  uint16_t bg = GxEPD_WHITE;
  uint16_t fg = GxEPD_BLACK;
  u8g2Fonts.setFontMode(1);                 // use u8g2 transparent mode (this is default)
  u8g2Fonts.setFontDirection(0);            // left to right (this is default)
  u8g2Fonts.setForegroundColor(fg);         // apply Adafruit GFX color
  u8g2Fonts.setBackgroundColor(bg);         // apply Adafruit GFX color
  u8g2Fonts.setFont(u8g2_font_helvR14_tf);  // select u8g2 font from here: https://github.com/olikraus/u8g2/wiki/fntlistall
  uint16_t x = (display.width() - 160) / 2;
  uint16_t y = display.height() / 4;
  display.setPartialWindow(0, y - 14, display.width(), 20);
  display.firstPage();
  do
  {
    display.fillScreen(bg);
    u8g2Fonts.setCursor(x, y);
    u8g2Fonts.println("Hello Arduino!");
  }
  while (display.nextPage());
  //Serial.println("helloArduino done");
}

void helloEpaper()
{
  //Serial.println("helloEpaper");
  uint16_t bg = GxEPD_WHITE;
  uint16_t fg = GxEPD_BLACK;
  u8g2Fonts.setFontMode(1);                 // use u8g2 transparent mode (this is default)
  u8g2Fonts.setFontDirection(0);            // left to right (this is default)
  u8g2Fonts.setForegroundColor(fg);         // apply Adafruit GFX color
  u8g2Fonts.setBackgroundColor(bg);         // apply Adafruit GFX color
  u8g2Fonts.setFont(u8g2_font_helvR14_tf);  // select u8g2 font from here: https://github.com/olikraus/u8g2/wiki/fntlistall
  uint16_t x = (display.width() - 160) / 2;
  uint16_t y = display.height() * 3 / 4;
  display.setPartialWindow(0, y - 14, display.width(), 20);
  display.firstPage();
  do
  {
    display.fillScreen(bg);
    u8g2Fonts.setCursor(x, y);
    u8g2Fonts.println("Hello E-Paper!");
  }
  while (display.nextPage());
  //Serial.println("helloEpaper done");
}

void showFont(const char name[], const uint8_t *font)
{
  display.setFullWindow();
  display.setRotation(0);
  u8g2Fonts.setFontMode(1);                   // use u8g2 transparent mode (this is default)
  u8g2Fonts.setFontDirection(0);              // left to right (this is default)
  u8g2Fonts.setForegroundColor(GxEPD_BLACK);  // apply Adafruit GFX color
  u8g2Fonts.setBackgroundColor(GxEPD_WHITE);  // apply Adafruit GFX color
  u8g2Fonts.setFont(font); // select u8g2 font from here: https://github.com/olikraus/u8g2/wiki/fntlistall
  display.firstPage();
  do
  {
    drawFont(name);
  }
  while (display.nextPage());
}

void drawFont(const char name[])
{
  //display.setRotation(0);
  display.fillScreen(GxEPD_WHITE);
  u8g2Fonts.setCursor(0, 0);
  u8g2Fonts.println();
  u8g2Fonts.println(name);
  u8g2Fonts.println(" !\"#$%&'()*+,-./");
  u8g2Fonts.println("0123456789:;<=>?");
  u8g2Fonts.println("@ABCDEFGHIJKLMNO");
  u8g2Fonts.println("PQRSTUVWXYZ[\\]^_");
  u8g2Fonts.println("`abcdefghijklmno");
  u8g2Fonts.println("pqrstuvwxyz{|}~ ");
  u8g2Fonts.println("Umlaut ÄÖÜäéöü");
}