[epaper_spi] Add support for Waveshare 2.13" V4 series B (R/B/W) (#16828)

esphome/components/epaper_spi/epaper_waveshare_b.cpp

@@ -0,0 +1,13 @@
+#include "epaper_waveshare_b.h"
+
+namespace esphome::epaper_spi {
+
+bool EpaperWaveshareB::reset() {
+  if (EPaperBase::reset()) {
+    this->command(0x12);
+    return true;
+  }
+  return false;
+}
+
+}  // namespace esphome::epaper_spi

esphome/components/epaper_spi/epaper_waveshare_b.h

@@ -0,0 +1,19 @@
+#pragma once
+#include "epaper_weact_3c.h"
+
+namespace esphome::epaper_spi {
+
+/**
+ * Waveshare (B) series BWR e-paper displays using SSD1680-compatible controllers.
+ * Waveshare uses 0=red, 1=no-red, the inverse of EPaperWeAct3C
+ */
+class EpaperWaveshareB : public EPaperWeAct3C {
+ public:
+  using EPaperWeAct3C::EPaperWeAct3C;
+
+ protected:
+  bool reset() override;
+  uint8_t transform_red_byte(uint8_t byte) const override { return static_cast<uint8_t>(~byte); }
+};
+
+}  // namespace esphome::epaper_spi

esphome/components/epaper_spi/epaper_weact_3c.cpp

@@ -144,7 +144,7 @@ bool HOT EPaperWeAct3C::transfer_data() {
       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_[red_offset + this->current_data_index_ + i];
+        bytes_to_send[i] = this->transform_red_byte(this->buffer_[red_offset + this->current_data_index_ + i]);
       }
 
       this->write_array(bytes_to_send, bytes_to_copy);

esphome/components/epaper_spi/epaper_weact_3c.h

@@ -34,6 +34,9 @@ class EPaperWeAct3C : public EPaperBase {
   void draw_pixel_at(int x, int y, Color color) override;
 
   bool transfer_data() override;
+
+  // Hook for subclasses to transform red plane bytes before they go on the wire.
+  virtual uint8_t transform_red_byte(uint8_t byte) const { return byte; }
 };
 
 }  // namespace esphome::epaper_spi

esphome/components/epaper_spi/models/waveshare_b.py

@@ -0,0 +1,26 @@
+from . import EpaperModel
+
+
+class WaveshareB(EpaperModel):
+    def __init__(self, name, **defaults):
+        super().__init__(name, "EpaperWaveshareB", **defaults)
+
+    def get_init_sequence(self, config):
+        _, height = self.get_dimensions(config)
+        h = height - 1
+        return (
+            (0x01, h & 0xFF, h >> 8, 0x00),  # Driver output control
+            (0x11, 0x03),  # Data entry mode
+            (0x3C, 0x05),  # Border waveform
+            (0x18, 0x80),  # Internal temperature sensor
+            (0x21, 0x80, 0x80),  # Display update control
+        )
+
+
+WaveshareB(
+    "waveshare-2.13in-bv4",
+    width=122,
+    height=250,
+    data_rate="10MHz",
+    minimum_update_interval="1s",
+)

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

@@ -162,6 +162,27 @@ display:
       allow_other_uses: true
       number: GPIO4
 
+  # Waveshare 2.13" V4 B series 3-color e-paper (122x250, BWR, SSD1680)
+  - platform: epaper_spi
+    spi_id: spi_bus
+    model: waveshare-2.13in-bv4
+    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, 20, Color::BLACK);
+      it.circle(it.get_width() / 2, it.get_height() / 2, 15, Color(255, 0, 0));
+
   # Soldered Inkplate 2 3-color e-paper (104x212, BWR)
   - platform: epaper_spi
     spi_id: spi_bus