From 160429eb24d08053be64ffb70a31aca82e001c5f Mon Sep 17 00:00:00 2001
From: Brett Profitt <brett.profitt@gmail.com>
Date: Tue, 3 Aug 2021 10:41:53 -0400
Subject: [PATCH] Add support for Waveshare E-Paper 4.2" B V2 (#1610)

Co-authored-by: Otto winter <otto@otto-winter.com>
---
 .../components/waveshare_epaper/display.py    |  4 ++
 .../waveshare_epaper/waveshare_epaper.cpp     | 56 +++++++++++++++++++
 .../waveshare_epaper/waveshare_epaper.h       | 29 ++++++++++
 3 files changed, 89 insertions(+)

diff --git a/esphome/components/waveshare_epaper/display.py b/esphome/components/waveshare_epaper/display.py
index 3e1132bb1d..a1a81e0997 100644
--- a/esphome/components/waveshare_epaper/display.py
+++ b/esphome/components/waveshare_epaper/display.py
@@ -31,6 +31,9 @@ WaveshareEPaper2P9InB = waveshare_epaper_ns.class_(
 WaveshareEPaper4P2In = waveshare_epaper_ns.class_(
     "WaveshareEPaper4P2In", WaveshareEPaper
 )
+WaveshareEPaper4P2InBV2 = waveshare_epaper_ns.class_(
+    "WaveshareEPaper4P2InBV2", WaveshareEPaper
+)
 WaveshareEPaper5P8In = waveshare_epaper_ns.class_(
     "WaveshareEPaper5P8In", WaveshareEPaper
 )
@@ -56,6 +59,7 @@ MODELS = {
     "2.70in": ("b", WaveshareEPaper2P7In),
     "2.90in-b": ("b", WaveshareEPaper2P9InB),
     "4.20in": ("b", WaveshareEPaper4P2In),
+    "4.20in-bv2": ("b", WaveshareEPaper4P2InBV2),
     "5.83in": ("b", WaveshareEPaper5P8In),
     "7.50in": ("b", WaveshareEPaper7P5In),
     "7.50inv2": ("b", WaveshareEPaper7P5InV2),
diff --git a/esphome/components/waveshare_epaper/waveshare_epaper.cpp b/esphome/components/waveshare_epaper/waveshare_epaper.cpp
index 458f04c674..cb1a158332 100644
--- a/esphome/components/waveshare_epaper/waveshare_epaper.cpp
+++ b/esphome/components/waveshare_epaper/waveshare_epaper.cpp
@@ -765,6 +765,62 @@ void WaveshareEPaper4P2In::dump_config() {
   LOG_UPDATE_INTERVAL(this);
 }
 
+// ========================================================
+//               4.20in Type B (LUT from OTP)
+// Datasheet:
+//  - https://www.waveshare.com/w/upload/2/20/4.2inch-e-paper-module-user-manual-en.pdf
+//  - https://github.com/waveshare/e-Paper/blob/master/RaspberryPi_JetsonNano/c/lib/e-Paper/EPD_4in2b_V2.c
+// ========================================================
+void WaveshareEPaper4P2InBV2::initialize() {
+  // these exact timings are required for a proper reset/init
+  this->reset_pin_->digital_write(false);
+  delay(2);
+  this->reset_pin_->digital_write(true);
+  delay(200);  // NOLINT
+
+  // COMMAND POWER ON
+  this->command(0x04);
+  this->wait_until_idle_();
+
+  // COMMAND PANEL SETTING
+  this->command(0x00);
+  this->data(0x0f);  // LUT from OTP
+}
+
+void HOT WaveshareEPaper4P2InBV2::display() {
+  // COMMAND DATA START TRANSMISSION 1 (B/W data)
+  this->command(0x10);
+  this->start_data_();
+  this->write_array(this->buffer_, this->get_buffer_length_());
+  this->end_data_();
+
+  // COMMAND DATA START TRANSMISSION 2 (RED data)
+  this->command(0x13);
+  this->start_data_();
+  for (int i = 0; i < this->get_buffer_length_(); i++)
+    this->write_byte(0xFF);
+  this->end_data_();
+  delay(2);
+
+  // COMMAND DISPLAY REFRESH
+  this->command(0x12);
+  this->wait_until_idle_();
+
+  // COMMAND POWER OFF
+  // NOTE: power off < deep sleep
+  this->command(0x02);
+}
+int WaveshareEPaper4P2InBV2::get_width_internal() { return 400; }
+int WaveshareEPaper4P2InBV2::get_height_internal() { return 300; }
+void WaveshareEPaper4P2InBV2::dump_config() {
+  LOG_DISPLAY("", "Waveshare E-Paper", this);
+  ESP_LOGCONFIG(TAG, "  Model: 4.2in (B V2)");
+  LOG_PIN("  Reset Pin: ", this->reset_pin_);
+  LOG_PIN("  DC Pin: ", this->dc_pin_);
+  LOG_PIN("  Busy Pin: ", this->busy_pin_);
+  LOG_UPDATE_INTERVAL(this);
+}
+
 void WaveshareEPaper5P8In::initialize() {
   // COMMAND POWER SETTING
   this->command(0x01);
diff --git a/esphome/components/waveshare_epaper/waveshare_epaper.h b/esphome/components/waveshare_epaper/waveshare_epaper.h
index 8ab77d653b..302238af7e 100644
--- a/esphome/components/waveshare_epaper/waveshare_epaper.h
+++ b/esphome/components/waveshare_epaper/waveshare_epaper.h
@@ -115,6 +115,7 @@ class WaveshareEPaperTypeA : public WaveshareEPaper {
 enum WaveshareEPaperTypeBModel {
   WAVESHARE_EPAPER_2_7_IN = 0,
   WAVESHARE_EPAPER_4_2_IN,
+  WAVESHARE_EPAPER_4_2_IN_B_V2,
   WAVESHARE_EPAPER_7_5_IN,
   WAVESHARE_EPAPER_7_5_INV2,
 };
@@ -202,6 +203,34 @@ class WaveshareEPaper4P2In : public WaveshareEPaper {
   int get_height_internal() override;
 };
 
+class WaveshareEPaper4P2InBV2 : public WaveshareEPaper {
+ public:
+  void initialize() override;
+
+  void display() override;
+
+  void dump_config() override;
+
+  void deep_sleep() override {
+    // COMMAND VCOM AND DATA INTERVAL SETTING
+    this->command(0x50);
+    this->data(0xF7);  // border floating
+
+    // COMMAND POWER OFF
+    this->command(0x02);
+    this->wait_until_idle_();
+
+    // COMMAND DEEP SLEEP
+    this->command(0x07);
+    this->data(0xA5);  // check code
+  }
+
+ protected:
+  int get_width_internal() override;
+
+  int get_height_internal() override;
+};
+
 class WaveshareEPaper5P8In : public WaveshareEPaper {
  public:
   void initialize() override;