Version 1.2.10

- added support for GDEH075Z90 7.5" b/w/r 880x528 - the controller of GDEH075Z90 supports partial update, but refesh is full screen - the controller of GDEH075Z90 doesn't support differential update (not possible on 3-color anyway) - note: the connector of the GDEH075Z90 is mirrored; connects downward on DESPI-C02 - added optional init parameter "reset_duration" in ms, same default 20ms as before - reset_duration = 2 may help with "clever" reset circuit of newer boards from Waveshare
ZinggJM · Jul 28, 2020 · bde0026 · bde0026
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diff --git a/README.md b/README.md
@@ -75,6 +75,7 @@
 - GDEW075T7      7.5" b/w 800x480
 - GDEW075Z09     7.5" b/w/r
 - GDEW075Z08     7.5" b/w/r 800x480
+- GDEH075Z90     7.5" b/w/r 880x528
 - GDEW1248T3    12.48 b/w 1304x984
 #### Supported SPI e-paper panels & boards from Waveshare: compare with Good Display, same panel
 #### other supported panels
@@ -84,7 +85,14 @@
 - promotion panels from suppliers are welcome, to add support to GxEPD2
 - donation panels from users are welcome, to add support to GxEPD2
 
-### Version 1.2.9
+### Version 1.2.10
+- added support for GDEH075Z90 7.5" b/w/r 880x528
+- the controller of GDEH075Z90 supports partial update, but refesh is full screen
+- the controller of GDEH075Z90 doesn't support differential update (not possible on 3-color anyway)
+- note: the connector of  the GDEH075Z90 is mirrored; connects downward on DESPI-C02
+- added optional init parameter "reset_duration" in ms, same default 20ms as before
+- reset_duration = 2 may help with "clever" reset circuit of newer boards from Waveshare
+#### Version 1.2.9
 - added support for GDEW0154T8 1.54" b/w 152x152
 - added support for GDEW0154M09 1.54" b/w 200x200
 - added support for GDEW0154M10 1.54" b/w 152x152 DES

diff --git a/examples/GxEPD2_Example/GxEPD2_Example.ino b/examples/GxEPD2_Example/GxEPD2_Example.ino
@@ -94,6 +94,7 @@
 //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));
 //GxEPD2_3C < GxEPD2_750c_Z08, GxEPD2_750c_Z08::HEIGHT / 4 > display(GxEPD2_750c_Z08(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4)); // GDEW075Z08 800x480
+//GxEPD2_3C < GxEPD2_750c_Z90, GxEPD2_750c_Z90::HEIGHT / 4 > display(GxEPD2_750c_Z90(/*CS=D8*/ SS, /*DC=D3*/ 0, /*RST=D4*/ 2, /*BUSY=D2*/ 4)); // GDEH075Z90 880x528
 // grey levels parallel IF e-papers on Waveshare e-Paper IT8951 Driver HAT
 // HRDY -> 4, RST -> 2, CS -> SS(15), SCK -> SCK(14), MOSI -> MOSI(D7(13)), MISO -> MISO(D6(12)), GND -> GND, 5V -> 5V
 // note: 5V supply needs to be exact and strong; 5V pin of USB powered Wemos D1 mini doesn't work!
@@ -132,6 +133,7 @@
 //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));
 //GxEPD2_3C<GxEPD2_750c_Z08, GxEPD2_750c_Z08::HEIGHT / 4> display(GxEPD2_750c_Z08(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, GxEPD2_750c_Z90::HEIGHT / 4> display(GxEPD2_750c_Z90(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=5*/ 5, /*BUSY=16*/ 16)); // GDEH075Z90 880x528
 #endif
 
 #if defined(ESP32)
@@ -164,6 +166,7 @@
 //GxEPD2_3C<GxEPD2_583c, GxEPD2_583c::HEIGHT> display(GxEPD2_583c(/*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));
 //GxEPD2_3C<GxEPD2_750c_Z08, GxEPD2_750c_Z08::HEIGHT> display(GxEPD2_750c_Z08(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, GxEPD2_750c_Z90::HEIGHT / 2> display(GxEPD2_750c_Z90(/*CS=5*/ SS, /*DC=*/ 17, /*RST=*/ 16, /*BUSY=*/ 4)); // GDEH075Z90 880x528
 
 // grey levels parallel IF e-papers on Waveshare e-Paper IT8951 Driver HAT
 // HRDY -> 4, RST -> 16, CS -> SS(5), SCK -> SCK(18), MOSI -> MOSI(23), MISO -> MISO(19), GND -> GND, 5V -> 5V
@@ -177,7 +180,8 @@
 //                             /*dc1=*/ 25, /*dc2=*/ 17, /*rst1=*/ 33, /*rst2=*/ 5, /*busy_m1=*/ 32, /*busy_s1=*/ 26, /*busy_m2=*/ 18, /*busy_s2=*/ 4));
 #endif
 
-#if defined(_BOARD_GENERIC_STM32F103C_H_)
+// can't use package "STMF1 Boards (STM32Duino.com)" (Roger Clark) anymore with Adafruit_GFX, use "STM32 Boards (selected from submenu)" (STMicroelectronics)
+#if defined(ARDUINO_ARCH_STM32)
 #define MAX_DISPLAY_BUFFER_SIZE 15000ul // ~15k is a good compromise
 #define MAX_HEIGHT(EPD) (EPD::HEIGHT <= MAX_DISPLAY_BUFFER_SIZE / (EPD::WIDTH / 8) ? EPD::HEIGHT : MAX_DISPLAY_BUFFER_SIZE / (EPD::WIDTH / 8))
 // select one and adapt to your mapping
@@ -210,6 +214,7 @@
 //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));
 //GxEPD2_3C<GxEPD2_750c_Z08, MAX_HEIGHT_3C(GxEPD2_750c_Z08)> display(GxEPD2_750c_Z08(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, MAX_HEIGHT_3C(GxEPD2_750c_Z90)> display(GxEPD2_750c_Z90(/*CS=4*/ SS, /*DC=*/ 3, /*RST=*/ 2, /*BUSY=*/ 1)); // GDEH075Z90 880x528
 #endif
 
 #if defined(__AVR)
@@ -249,6 +254,7 @@
 //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));
 //GxEPD2_3C<GxEPD2_750c_Z08, MAX_HEIGHT_3C(GxEPD2_750c_Z08)> display(GxEPD2_750c_Z08(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, MAX_HEIGHT_3C(GxEPD2_750c_Z90)> display(GxEPD2_750c_Z90(/*CS=10*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7)); // GDEH075Z90 880x528
 
 // ***** for mapping of Waveshare Universal e-Paper Raw Panel Driver Shield for Arduino / NUCLEO *****
 // the RST line is not connected through level converter, but has a pull up resistor and a pull down diode to the Arduino pin; this is safe for 5V Arduino
@@ -285,6 +291,7 @@
 //GxEPD2_3C<GxEPD2_583c, MAX_HEIGHT_3C(GxEPD2_583c)> display(GxEPD2_583c(/*CS=10*/ SS, /*DC=*/ 9, /*RST=*/ 8, /*BUSY=*/ 7));
 //GxEPD2_3C<GxEPD2_750c, MAX_HEIGHT_3C(GxEPD2_750c)> display(GxEPD2_750c(/*CS=10*/ SS, /*DC=*/ 9, /*RST=*/ 8, /*BUSY=*/ 7));
 //GxEPD2_3C<GxEPD2_750c_Z08, MAX_HEIGHT_3C(GxEPD2_750c_Z08)> display(GxEPD2_750c_Z08(/*CS=10*/ SS, /*DC=*/ 9, /*RST=*/ 8, /*BUSY=*/ 7)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, MAX_HEIGHT_3C(GxEPD2_750c_Z90)> display(GxEPD2_750c_Z90(/*CS=10*/ SS, /*DC=*/ 9, /*RST=*/ 8, /*BUSY=*/ 7)); //GDEH075Z90 880x528
 
 // Waveshare 12.48 b/w SPI display board and frame or Good Display 12.48 b/w panel GDEW1248T3
 // general constructor for use with standard SPI pins, default SCK, MISO and MOSI, for UNO on UNO connectors
@@ -322,6 +329,7 @@
 #include "bitmaps/Bitmaps3c400x300.h" // 4.2"  b/w/r
 #if defined(ESP8266) || defined(ESP32)
 #include "bitmaps/Bitmaps3c800x480.h" // 7.5"  b/w/r
+#include "bitmaps/Bitmaps3c880x528.h" // 7.5"  b/w/r
 #include "bitmaps/WS_Bitmaps800x600.h" // 6.0"  grey
 #endif
 #if defined(ESP32)
@@ -913,6 +921,9 @@ void drawBitmaps()
 #endif
 #ifdef _GxBitmaps3c800x480_H_
   drawBitmaps3c800x480();
+#endif
+#ifdef _GxBitmaps3c880x528_H_
+  drawBitmaps3c880x528();
 #endif
   if ((display.epd2.WIDTH >= 200) && (display.epd2.HEIGHT >= 200))
   {
@@ -971,10 +982,10 @@ void drawBitmaps200x200()
   {
     logo200x200, //first200x200
   };
-#elif defined(_BOARD_GENERIC_STM32F103C_H_)
+#elif defined(_BOARD_GENERIC_STM32F103C_H_) || defined(STM32F1xx)
   const unsigned char* bitmaps[] =
   {
-    logo200x200, first200x200, second200x200, third200x200, fourth200x200, fifth200x200 //, sixth200x200, senventh200x200, eighth200x200
+    logo200x200, first200x200, second200x200, third200x200, //fourth200x200, fifth200x200, sixth200x200, senventh200x200, eighth200x200
   };
 #else
   const unsigned char* bitmaps[] =
@@ -1643,3 +1654,34 @@ void drawBitmaps3c800x480()
   }
 }
 #endif
+
+#ifdef _GxBitmaps3c880x528_H_
+void drawBitmaps3c880x528()
+{
+#if !defined(__AVR)
+  bitmap_pair bitmap_pairs[] =
+  {
+    {Bitmap3c880x528_black, Bitmap3c880x528_red}
+  };
+#else
+  bitmap_pair bitmap_pairs[] = {}; // not enough code space
+#endif
+  if (display.epd2.panel == GxEPD2::GDEH075Z90)
+  {
+    bool m = display.mirror(true);
+    for (uint16_t i = 0; i < sizeof(bitmap_pairs) / sizeof(bitmap_pair); i++)
+    {
+      display.firstPage();
+      do
+      {
+        display.fillScreen(GxEPD_WHITE);
+        display.drawInvertedBitmap(0, 0, bitmap_pairs[i].black, 880, 528, GxEPD_BLACK);
+        display.drawInvertedBitmap(0, 0, bitmap_pairs[i].red, 880, 528, GxEPD_RED);
+      }
+      while (display.nextPage());
+      delay(2000);
+    }
+    display.mirror(m);
+  }
+}
+#endif
diff --git a/examples/GxEPD2_Example/GxEPD2_boards_added.h b/examples/GxEPD2_Example/GxEPD2_boards_added.h
@@ -51,6 +51,7 @@
 //GxEPD2_3C<GxEPD2_583c, MAX_HEIGHT_3C(GxEPD2_583c)> display(GxEPD2_583c(/*CS=77*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
 //GxEPD2_3C<GxEPD2_750c, MAX_HEIGHT_3C(GxEPD2_750c)> display(GxEPD2_750c(/*CS=77*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7));
 //GxEPD2_3C<GxEPD2_750c_Z08, MAX_HEIGHT_3C(GxEPD2_750c_Z08)> display(GxEPD2_750c_Z08(/*CS=77*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, MAX_HEIGHT_3C(GxEPD2_750c_Z90)> display(GxEPD2_750c_Z90(/*CS=77*/ SS, /*DC=*/ 8, /*RST=*/ 9, /*BUSY=*/ 7)); // GDEH075Z90 880x528
 #endif
 
 // Arduino MKR1000 or MKRZERO
@@ -92,6 +93,7 @@
 //GxEPD2_3C<GxEPD2_583c, MAX_HEIGHT_3C(GxEPD2_583c)> display(GxEPD2_583c(/*CS=4*/ 4, /*DC=*/ 7, /*RST=*/ 6, /*BUSY=*/ 5));
 //GxEPD2_3C<GxEPD2_750c, MAX_HEIGHT_3C(GxEPD2_750c)> display(GxEPD2_750c(/*CS=4*/ 4, /*DC=*/ 7, /*RST=*/ 6, /*BUSY=*/ 5));
 //GxEPD2_3C<GxEPD2_750c_Z08, MAX_HEIGHT_3C(GxEPD2_750c_Z08)> display(GxEPD2_750c_Z08(/*CS=4*/ 4, /*DC=*/ 7, /*RST=*/ 6, /*BUSY=*/ 5)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, MAX_HEIGHT_3C(GxEPD2_750c_Z90)> display(GxEPD2_750c_Z90(/*CS=4*/ 4, /*DC=*/ 7, /*RST=*/ 6, /*BUSY=*/ 5)); // GDEH075Z90 880x528
 #endif
 
 // mapping suggestion for ESP32, e.g. LOLIN32 D32 PRO
@@ -128,6 +130,7 @@
 //GxEPD2_3C<GxEPD2_583c, GxEPD2_583c::HEIGHT> display(GxEPD2_583c(/*CS=5*/ 5, /*DC=*/ 0, /*RST=*/ 2, /*BUSY=*/ 15));
 //GxEPD2_3C<GxEPD2_750c, GxEPD2_750c::HEIGHT> display(GxEPD2_750c(/*CS=5*/ 5, /*DC=*/ 0, /*RST=*/ 2, /*BUSY=*/ 15));
 //GxEPD2_3C<GxEPD2_750c_Z08, GxEPD2_750c_Z08::HEIGHT> display(GxEPD2_750c_Z08(/*CS=5*/ 5, /*DC=*/ 0, /*RST=*/ 2, /*BUSY=*/ 15)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, GxEPD2_750c_Z90::HEIGHT> display(GxEPD2_750c_Z90(/*CS=5*/ 5, /*DC=*/ 0, /*RST=*/ 2, /*BUSY=*/ 15)); // GDEH075Z90 880x528
 // grey levels parallel IF e-papers on Waveshare e-Paper IT8951 Driver HAT
 // HRDY -> 4, RST -> 16, CS -> 5, SCK -> SCK(18), MOSI -> MOSI(23), MISO -> MISO(19), GND -> GND, 5V -> 5V
 // note: 5V supply needs to be exact and strong; 5V over diode from USB (e.g. Wemos D1 mini) doesn't work!
@@ -168,6 +171,7 @@
 //GxEPD2_3C<GxEPD2_583c, GxEPD2_583c::HEIGHT> display(GxEPD2_583c(/*CS=5*/ 5, /*DC=*/ 2, /*RST=*/ 0, /*BUSY=*/ 4));
 //GxEPD2_3C<GxEPD2_750c, GxEPD2_750c::HEIGHT> display(GxEPD2_750c(/*CS=5*/ 5, /*DC=*/ 2, /*RST=*/ 0, /*BUSY=*/ 4));
 //GxEPD2_3C<GxEPD2_750c_Z08, GxEPD2_750c_Z08::HEIGHT> display(GxEPD2_750c_Z08(/*CS=5*/ 5, /*DC=*/ 2, /*RST=*/ 0, /*BUSY=*/ 4)); // GDEW075Z08 800x480
+//GxEPD2_3C<GxEPD2_750c_Z90, GxEPD2_750c_Z90::HEIGHT> display(GxEPD2_750c_Z90(/*CS=5*/ 5, /*DC=*/ 2, /*RST=*/ 0, /*BUSY=*/ 4)); // GDEH075Z90 880x528
 // grey levels parallel IF e-papers on Waveshare e-Paper IT8951 Driver HAT
 // HRDY -> 4, RST -> 16, CS -> SS(5), SCK -> SCK(18), MOSI -> MOSI(23), MISO -> MISO(19), GND -> GND, 5V -> 5V
 // note: 5V supply needs to be exact and strong; 5V over diode from USB (e.g. Wemos D1 mini) doesn't work!

diff --git a/library.properties b/library.properties
@@ -1,5 +1,5 @@
 name=GxEPD2
-version=1.2.9
+version=1.2.10
 author=Jean-Marc Zingg
 maintainer=Jean-Marc Zingg
 sentence=Arduino Display Library for SPI E-Paper displays from Dalian Good Display and Waveshare. 

diff --git a/src/GxEPD2.h b/src/GxEPD2.h
@@ -58,7 +58,8 @@ class GxEPD2
       GDEW042Z15,  Waveshare_4_2_bwr = GDEW042Z15,
       GDEW0583Z21, Waveshare_5_83_bwr = GDEW0583Z21,
       GDEW075Z09,  Waveshare_7_5_bwr = GDEW075Z09,
-      GDEW075Z08,  Waveshare_7_5_bwr_Z08 = GDEW075Z08
+      GDEW075Z08,  Waveshare_7_5_bwr_Z08 = GDEW075Z08,
+      GDEH075Z90,  Waveshare_7_5_bwr_Z90 = GDEH075Z90
     };
 };
 

diff --git a/src/GxEPD2_3C.h b/src/GxEPD2_3C.h
@@ -38,6 +38,7 @@
 #include "epd3c/GxEPD2_583c.h"
 #include "epd3c/GxEPD2_750c.h"
 #include "epd3c/GxEPD2_750c_Z08.h"
+#include "epd3c/GxEPD2_750c_Z90.h"
 
 template<typename GxEPD2_Type, const uint16_t page_height>
 class GxEPD2_3C : public GxEPD2_GFX_BASE_CLASS
@@ -121,10 +122,11 @@ class GxEPD2_3C : public GxEPD2_GFX_BASE_CLASS
     // init method with additional parameters:
     // initial false for re-init after processor deep sleep wake up, if display power supply was kept
     // only relevant for b/w displays with fast partial update
+    // reset_duration = 20 is default; a value of 2 may help with "clever" reset circuit of newer boards from Waveshare 
     // pulldown_rst_mode true for alternate RST handling to avoid feeding 5V through RST pin
-    void init(uint32_t serial_diag_bitrate, bool initial, bool pulldown_rst_mode = false)
+    void init(uint32_t serial_diag_bitrate, bool initial, uint16_t reset_duration = 20, bool pulldown_rst_mode = false)
     {
-      epd2.init(serial_diag_bitrate, initial, pulldown_rst_mode);
+      epd2.init(serial_diag_bitrate, initial, reset_duration, pulldown_rst_mode);
       _using_partial_mode = false;
       _current_page = 0;
       setFullWindow();

diff --git a/src/GxEPD2_BW.h b/src/GxEPD2_BW.h
@@ -137,10 +137,11 @@ class GxEPD2_BW : public GxEPD2_GFX_BASE_CLASS
     // initial false for re-init after processor deep sleep wake up, if display power supply was kept
     // this can be used to avoid the repeated initial full refresh on displays with fast partial update
     // NOTE: garbage will result on fast partial update displays, if initial full update is omitted after power loss
+    // reset_duration = 20 is default; a value of 2 may help with "clever" reset circuit of newer boards from Waveshare 
     // pulldown_rst_mode true for alternate RST handling to avoid feeding 5V through RST pin
-    void init(uint32_t serial_diag_bitrate, bool initial, bool pulldown_rst_mode = false)
+    void init(uint32_t serial_diag_bitrate, bool initial, uint16_t reset_duration = 20, bool pulldown_rst_mode = false)
     {
-      epd2.init(serial_diag_bitrate, initial, pulldown_rst_mode);
+      epd2.init(serial_diag_bitrate, initial, reset_duration, pulldown_rst_mode);
       _using_partial_mode = false;
       _current_page = 0;
       setFullWindow();

diff --git a/src/GxEPD2_EPD.cpp b/src/GxEPD2_EPD.cpp
@@ -28,21 +28,23 @@ GxEPD2_EPD::GxEPD2_EPD(int8_t cs, int8_t dc, int8_t rst, int8_t busy, int8_t bus
   _power_is_on = false;
   _using_partial_mode = false;
   _hibernating = false;
+  _reset_duration = 20;
 }
 
 void GxEPD2_EPD::init(uint32_t serial_diag_bitrate)
 {
-  init(serial_diag_bitrate, true, false);
+  init(serial_diag_bitrate, true, 20, false);
 }
 
-void GxEPD2_EPD::init(uint32_t serial_diag_bitrate, bool initial, bool pulldown_rst_mode)
+void GxEPD2_EPD::init(uint32_t serial_diag_bitrate, bool initial, uint16_t reset_duration, bool pulldown_rst_mode)
 {
   _initial_write = initial;
   _initial_refresh = initial;
   _pulldown_rst_mode = pulldown_rst_mode;
   _power_is_on = false;
   _using_partial_mode = false;
   _hibernating = false;
+  _reset_duration = reset_duration;
   if (serial_diag_bitrate > 0)
   {
     Serial.begin(serial_diag_bitrate);
@@ -74,7 +76,7 @@ void GxEPD2_EPD::_reset()
     {
       digitalWrite(_rst, LOW);
       pinMode(_rst, OUTPUT);
-      delay(20);
+      delay(_reset_duration);
       pinMode(_rst, INPUT_PULLUP);
       delay(200);
     }
@@ -84,7 +86,7 @@ void GxEPD2_EPD::_reset()
       pinMode(_rst, OUTPUT);
       delay(20);
       digitalWrite(_rst, LOW);
-      delay(20);
+      delay(_reset_duration);
       digitalWrite(_rst, HIGH);
       delay(200);
     }

diff --git a/src/GxEPD2_EPD.h b/src/GxEPD2_EPD.h
@@ -33,7 +33,7 @@ class GxEPD2_EPD
     GxEPD2_EPD(int8_t cs, int8_t dc, int8_t rst, int8_t busy, int8_t busy_level, uint32_t busy_timeout,
                uint16_t w, uint16_t h, GxEPD2::Panel p, bool c, bool pu, bool fpu);
     virtual void init(uint32_t serial_diag_bitrate = 0); // serial_diag_bitrate = 0 : disabled
-    virtual void init(uint32_t serial_diag_bitrate, bool initial, bool pulldown_rst_mode = false);
+    virtual void init(uint32_t serial_diag_bitrate, bool initial, uint16_t reset_duration = 20, bool pulldown_rst_mode = false);
     //  Support for Bitmaps (Sprites) to Controller Buffer and to Screen
     virtual void clearScreen(uint8_t value) = 0; // init controller memory and screen (default white)
     virtual void writeScreenBuffer(uint8_t value) = 0; // init controller memory (default white)
@@ -105,6 +105,7 @@ class GxEPD2_EPD
     SPISettings _spi_settings;
     bool _initial_write, _initial_refresh;
     bool _power_is_on, _using_partial_mode, _hibernating;
+    uint16_t _reset_duration;
 };
 
 #endif
diff --git a/src/GxEPD2_GFX.h b/src/GxEPD2_GFX.h
@@ -37,7 +37,7 @@ class GxEPD2_GFX : public GxEPD2_GFX_ROOT_CLASS
     // this can be used to avoid the repeated initial full refresh on displays with fast partial update
     // NOTE: garbage will result on fast partial update displays, if initial full update is omitted after power loss
     // pulldown_rst_mode true for alternate RST handling to avoid feeding 5V through RST pin
-    virtual void init(uint32_t serial_diag_bitrate, bool initial, bool pulldown_rst_mode = false) = 0;
+    virtual void init(uint32_t serial_diag_bitrate, bool initial, uint16_t reset_duration = 20, bool pulldown_rst_mode = false) = 0;
     virtual void fillScreen(uint16_t color) = 0; // 0x0 black, >0x0 white, to buffer
     // display buffer content to screen, useful for full screen buffer
     virtual void display(bool partial_update_mode = false) = 0;