[epaper_spi] Add Waveshare 7.5" V2 BWR support (#15719)

esphome/components/epaper_spi/epaper_waveshare_bwr.cpp

@@ -0,0 +1,146 @@
+#include "epaper_waveshare_bwr.h"
+
+#include <algorithm>
+
+namespace esphome::epaper_spi {
+
+enum class BwrState : uint8_t {
+  BWR_BLACK,
+  BWR_WHITE,
+  BWR_RED,
+};
+
+static BwrState color_to_bwr(Color color) {
+  if (color.r > color.g + color.b && color.r > 127) {
+    return BwrState::BWR_RED;
+  }
+  if (color.r + color.g + color.b >= 382) {
+    return BwrState::BWR_WHITE;
+  }
+  return BwrState::BWR_BLACK;
+}
+
+// UC8179 3-color display buffer layout:
+// - 1 bit per pixel, 8 pixels per byte
+// - Buffer first half: Black/White plane (1=black, 0=white)
+// - Buffer second half: Red plane (1=red, 0=white)
+// - Total: row_width * height * 2 bytes
+
+void EPaperWaveshareBWR::draw_pixel_at(int x, int y, Color color) {
+  if (!this->rotate_coordinates_(x, y))
+    return;
+
+  const uint32_t pos = (x / 8) + (y * this->row_width_);
+  const uint8_t bit = 0x80 >> (x & 0x07);
+  const uint32_t red_offset = this->buffer_length_ / 2u;
+
+  const auto bwr = color_to_bwr(color);
+
+  if (bwr == BwrState::BWR_BLACK) {
+    this->buffer_[pos] |= bit;
+  } else {
+    this->buffer_[pos] &= ~bit;
+  }
+
+  if (bwr == BwrState::BWR_RED) {
+    this->buffer_[red_offset + pos] |= bit;
+  } else {
+    this->buffer_[red_offset + pos] &= ~bit;
+  }
+}
+
+void EPaperWaveshareBWR::fill(Color color) {
+  const size_t half_buffer = this->buffer_length_ / 2u;
+  const auto bwr = color_to_bwr(color);
+
+  if (bwr == BwrState::BWR_BLACK) {
+    // Black plane: 0xFF (black), Red plane: 0x00 (no red)
+    for (size_t i = 0; i < half_buffer; i++)
+      this->buffer_[i] = 0xFF;
+    for (size_t i = 0; i < half_buffer; i++)
+      this->buffer_[half_buffer + i] = 0x00;
+  } else if (bwr == BwrState::BWR_RED) {
+    // Black plane: 0x00 (no black), Red plane: 0xFF (red)
+    for (size_t i = 0; i < half_buffer; i++)
+      this->buffer_[i] = 0x00;
+    for (size_t i = 0; i < half_buffer; i++)
+      this->buffer_[half_buffer + i] = 0xFF;
+  } else {
+    // Black plane: 0x00 (no black), Red plane: 0x00 (no red)
+    this->buffer_.fill(0x00);
+  }
+}
+
+bool HOT EPaperWaveshareBWR::transfer_data() {
+  const uint32_t start_time = millis();
+  const size_t buffer_length = this->buffer_length_;
+  const size_t half_buffer = buffer_length / 2u;
+
+  uint8_t bytes_to_send[MAX_TRANSFER_SIZE];
+
+  // Phase 1: send Black/White plane (first half) via command 0x10 (DTM1)
+  // UC8179 DTM1 (0x10): inverted to get 0=black, 1=white
+  if (this->current_data_index_ < half_buffer) {
+    if (this->current_data_index_ == 0) {
+      this->command(0x10);  // DATA START TRANSMISSION 1 (black channel)
+    }
+    this->start_data_();
+    while (this->current_data_index_ < half_buffer) {
+      const size_t bytes_to_copy = std::min(MAX_TRANSFER_SIZE, half_buffer - this->current_data_index_);
+      for (size_t i = 0; i < bytes_to_copy; i++) {
+        bytes_to_send[i] = ~this->buffer_[this->current_data_index_ + i];
+      }
+      this->write_array(bytes_to_send, bytes_to_copy);
+      this->current_data_index_ += bytes_to_copy;
+      if (millis() - start_time > MAX_TRANSFER_TIME) {
+        this->disable();
+        return false;
+      }
+    }
+    this->disable();
+  }
+
+  // Phase 2: send Red plane (second half) via command 0x13 (DTM2)
+  // UC8179 DTM2 (0x13): 1=red, 0=white
+  if (this->current_data_index_ < buffer_length) {
+    if (this->current_data_index_ == half_buffer) {
+      this->command(0x13);  // DATA START TRANSMISSION 2 (red channel)
+    }
+    this->start_data_();
+    while (this->current_data_index_ < buffer_length) {
+      const size_t bytes_to_copy = std::min(MAX_TRANSFER_SIZE, buffer_length - this->current_data_index_);
+      for (size_t i = 0; i < bytes_to_copy; i++) {
+        bytes_to_send[i] = this->buffer_[this->current_data_index_ + i];
+      }
+      this->write_array(bytes_to_send, bytes_to_copy);
+      this->current_data_index_ += bytes_to_copy;
+      if (millis() - start_time > MAX_TRANSFER_TIME) {
+        this->disable();
+        return false;
+      }
+    }
+    this->disable();
+  }
+
+  this->current_data_index_ = 0;
+  return true;
+}
+
+void EPaperWaveshareBWR::power_on() {
+  this->cmd_data(0x01, {0x07, 0x17, 0x3F, 0x3F});  // POWER SETTING
+  this->command(0x04);                             // POWER ON
+}
+
+void EPaperWaveshareBWR::refresh_screen(bool /*partial*/) {
+  this->command(0x12);  // DISPLAY REFRESH
+}
+
+void EPaperWaveshareBWR::power_off() {
+  this->command(0x02);  // POWER OFF
+}
+
+void EPaperWaveshareBWR::deep_sleep() {
+  this->cmd_data(0x07, {0xA5});  // DEEP SLEEP with check code
+}
+
+}  // namespace esphome::epaper_spi

esphome/components/epaper_spi/epaper_waveshare_bwr.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include "epaper_spi.h"
+
+namespace esphome::epaper_spi {
+
+/**
+ * Waveshare 3-color e-paper displays (UC8179 controller).
+ * Supports: 7.5" V2 BWR (EDP_7in5b_V2), 800x480 pixels.
+ *
+ * Color scheme: Black, White, Red (BWR)
+ * Buffer layout: 1 bit per pixel, separate planes
+ * - Buffer first half: Black/White plane (1=black, 0=white)
+ * - Buffer second half: Red plane (1=red, 0=no red)
+ * - Total buffer: width * height / 4 bytes (2 * width * height / 8)
+ *
+ * The init sequence (INITIALISE state) sends panel configuration only.
+ * Power-on (0x01 + 0x04) is sent in the POWER_ON state after data transfer;
+ * the state machine then busy-waits before triggering REFRESH_SCREEN (0x12).
+ */
+class EPaperWaveshareBWR : public EPaperBase {
+ public:
+  EPaperWaveshareBWR(const char *name, uint16_t width, uint16_t height, const uint8_t *init_sequence,
+                     size_t init_sequence_length)
+      : EPaperBase(name, width, height, init_sequence, init_sequence_length, DISPLAY_TYPE_BINARY) {
+    this->buffer_length_ = this->row_width_ * height * 2;
+  }
+
+  void fill(Color color) override;
+
+ protected:
+  void draw_pixel_at(int x, int y, Color color) override;
+  bool transfer_data() override;
+  void refresh_screen(bool partial) override;
+  void power_on() override;
+  void power_off() override;
+  void deep_sleep() override;
+};
+
+}  // namespace esphome::epaper_spi

esphome/components/epaper_spi/models/waveshare_bwr.py

@@ -0,0 +1,56 @@
+"""Waveshare Black/White/Red e-paper displays using UC8179 controller.
+
+Supported models:
+- waveshare-7.5in-bv2-bwr: 800x480 pixels (7.5" BWR display, EDP_7in5b_V2)
+
+These displays use the UC8179 controller. Panel configuration is sent during
+the INITIALISE state. Power-on is handled in the POWER_ON state, after data
+transfer, so the state machine's built-in busy wait covers the power-on delay.
+"""
+
+from . import EpaperModel
+
+
+class WaveshareBWR(EpaperModel):
+    """EpaperModel class for Waveshare Black/White/Red displays using UC8179 controller."""
+
+    def __init__(self, name, **defaults):
+        super().__init__(name, "EPaperWaveshareBWR", **defaults)
+
+    def get_init_sequence(self, config):
+        """Generate initialization sequence for UC8179 BWR displays.
+
+        Panel configuration only — power-on is handled separately in power_on()
+        after data transfer, with the state machine busy-waiting before refresh.
+        """
+        width, height = self.get_dimensions(config)
+        return (
+            # PANEL SETTING (KWR mode)
+            (0x00, 0x0F),
+            # RESOLUTION SETTING (width x height)
+            (
+                0x61,
+                (width >> 8) & 0xFF,
+                width & 0xFF,
+                (height >> 8) & 0xFF,
+                height & 0xFF,
+            ),
+            # DUAL SPI MODE (disabled)
+            (0x15, 0x00),
+            # VCOM AND DATA INTERVAL SETTING
+            (0x50, 0x11, 0x07),
+            # TCON SETTING
+            (0x60, 0x22),
+            # RESOLUTION GATE SETTING
+            (0x65, 0x00, 0x00, 0x00, 0x00),
+        )
+
+
+# Model: Waveshare 7.5" V2 BWR (EDP_7in5b_V2) — 800x480, UC8179 controller
+WaveshareBWR(
+    "waveshare-7.5in-bv2-bwr",
+    width=800,
+    height=480,
+    data_rate="10MHz",
+    minimum_update_interval="30s",
+)

tests/components/epaper_spi/test.esp32-s3-idf.yaml

@@ -203,3 +203,24 @@ display:
       it.filled_rectangle(0, 0, it.get_width(), it.get_height(), Color::WHITE);
       it.circle(it.get_width() / 2, it.get_height() / 2, 20, Color::BLACK);
       it.circle(it.get_width() / 2, it.get_height() / 2, 15, Color(255, 0, 0));
+
+  # Waveshare 7.5" V2 BWR (800x480, UC8179 controller, EDP_7in5b_V2)
+  - platform: epaper_spi
+    spi_id: spi_bus
+    model: waveshare-7.5in-bv2-bwr
+    cs_pin:
+      allow_other_uses: true
+      number: GPIO5
+    dc_pin:
+      allow_other_uses: true
+      number: GPIO17
+    reset_pin:
+      allow_other_uses: true
+      number: GPIO16
+    busy_pin:
+      allow_other_uses: true
+      number: GPIO4
+    lambda: |-
+      it.filled_rectangle(0, 0, it.get_width(), it.get_height(), Color::WHITE);
+      it.circle(it.get_width() / 2, it.get_height() / 2, 100, Color::BLACK);
+      it.circle(it.get_width() / 2, it.get_height() / 2, 60, Color(255, 0, 0));