Add st7920 display, (#1440)

Co-authored-by: Oxan van Leeuwen <oxan@oxanvanleeuwen.nl>
Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

CODEOWNERS

@@ -129,6 +129,7 @@ esphome/components/ssd1351_base/* @kbx81
 esphome/components/ssd1351_spi/* @kbx81
 esphome/components/st7735/* @SenexCrenshaw
 esphome/components/st7789v/* @kbx81
+esphome/components/st7920/* @marsjan155
 esphome/components/substitutions/* @esphome/core
 esphome/components/sun/* @OttoWinter
 esphome/components/switch/* @esphome/core

esphome/components/st7920/display.py

@@ -0,0 +1,42 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import display, spi
+from esphome.const import CONF_ID, CONF_LAMBDA, CONF_WIDTH, CONF_HEIGHT
+
+AUTO_LOAD = ["display"]
+CODEOWNERS = ["@marsjan155"]
+DEPENDENCIES = ["spi"]
+
+st7920_ns = cg.esphome_ns.namespace("st7920")
+ST7920 = st7920_ns.class_(
+    "ST7920", cg.PollingComponent, display.DisplayBuffer, spi.SPIDevice
+)
+ST7920Ref = ST7920.operator("ref")
+
+CONFIG_SCHEMA = (
+    display.FULL_DISPLAY_SCHEMA.extend(
+        {
+            cv.GenerateID(): cv.declare_id(ST7920),
+            cv.Required(CONF_WIDTH): cv.int_,
+            cv.Required(CONF_HEIGHT): cv.int_,
+        }
+    )
+    .extend(cv.polling_component_schema("60s"))
+    .extend(spi.spi_device_schema())
+)
+
+
+async def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)
+    await spi.register_spi_device(var, config)
+
+    if CONF_LAMBDA in config:
+        lambda_ = await cg.process_lambda(
+            config[CONF_LAMBDA], [(ST7920Ref, "it")], return_type=cg.void
+        )
+        cg.add(var.set_writer(lambda_))
+    cg.add(var.set_width(config[CONF_WIDTH]))
+    cg.add(var.set_height(config[CONF_HEIGHT]))
+
+    await display.register_display(var, config)

esphome/components/st7920/st7920.cpp

@@ -0,0 +1,146 @@
+#include "st7920.h"
+#include "esphome/core/log.h"
+#include "esphome/core/application.h"
+#include "esphome/components/display/display_buffer.h"
+
+namespace esphome {
+namespace st7920 {
+
+static const char *const TAG = "st7920";
+
+// ST7920 COMMANDS
+static const uint8_t LCD_DATA = 0xFA;
+static const uint8_t LCD_COMMAND = 0xF8;
+static const uint8_t LCD_CLS = 0x01;
+static const uint8_t LCD_HOME = 0x02;
+static const uint8_t LCD_ADDRINC = 0x06;
+static const uint8_t LCD_DISPLAYON = 0x0C;
+static const uint8_t LCD_DISPLAYOFF = 0x08;
+static const uint8_t LCD_CURSORON = 0x0E;
+static const uint8_t LCD_CURSORBLINK = 0x0F;
+static const uint8_t LCD_BASIC = 0x30;
+static const uint8_t LCD_GFXMODE = 0x36;
+static const uint8_t LCD_EXTEND = 0x34;
+static const uint8_t LCD_TXTMODE = 0x34;
+static const uint8_t LCD_STANDBY = 0x01;
+static const uint8_t LCD_SCROLL = 0x03;
+static const uint8_t LCD_SCROLLADDR = 0x40;
+static const uint8_t LCD_ADDR = 0x80;
+static const uint8_t LCD_LINE0 = 0x80;
+static const uint8_t LCD_LINE1 = 0x90;
+static const uint8_t LCD_LINE2 = 0x88;
+static const uint8_t LCD_LINE3 = 0x98;
+
+void ST7920::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up ST7920...");
+  this->dump_config();
+  this->spi_setup();
+  this->init_internal_(this->get_buffer_length_());
+  display_init_();
+}
+
+void ST7920::command_(uint8_t value) {
+  this->enable();
+  this->send_(LCD_COMMAND, value);
+  this->disable();
+}
+
+void ST7920::data_(uint8_t value) {
+  this->enable();
+  this->send_(LCD_DATA, value);
+  this->disable();
+}
+
+void ST7920::send_(uint8_t type, uint8_t value) {
+  this->write_byte(type);
+  this->write_byte(value & 0xF0);
+  this->write_byte(value << 4);
+}
+
+void ST7920::goto_xy_(uint16_t x, uint16_t y) {
+  if (y >= 32 && y < 64) {
+    y -= 32;
+    x += 8;
+  } else if (y >= 64 && y < 64 + 32) {
+    y -= 32;
+    x += 0;
+  } else if (y >= 64 + 32 && y < 64 + 64) {
+    y -= 64;
+    x += 8;
+  }
+  this->command_(LCD_ADDR | y);  // 6-bit (0..63)
+  this->command_(LCD_ADDR | x);  // 4-bit (0..15)
+}
+
+void HOT ST7920::write_display_data() {
+  uint8_t i, j, b;
+  for (j = 0; j < this->get_height_internal() / 2; j++) {
+    this->goto_xy_(0, j);
+    this->enable();
+    for (i = 0; i < 16; i++) {  // 16 bytes from line #0+
+      b = this->buffer_[i + j * 16];
+      this->send_(LCD_DATA, b);
+    }
+    for (i = 0; i < 16; i++) {  // 16 bytes from line #32+
+      b = this->buffer_[i + (j + 32) * 16];
+      this->send_(LCD_DATA, b);
+    }
+    this->disable();
+    App.feed_wdt();
+  }
+}
+
+void ST7920::fill(Color color) { memset(this->buffer_, color.is_on() ? 0xFF : 0x00, this->get_buffer_length_()); }
+
+void ST7920::dump_config() {
+  LOG_DISPLAY("", "ST7920", this);
+  LOG_PIN("  CS Pin: ", this->cs_);
+  ESP_LOGCONFIG(TAG, "  Height: %d", this->height_);
+  ESP_LOGCONFIG(TAG, "  Width: %d", this->width_);
+}
+
+float ST7920::get_setup_priority() const { return setup_priority::PROCESSOR; }
+
+void ST7920::update() {
+  this->clear();
+  if (this->writer_local_.has_value())  // call lambda function if available
+    (*this->writer_local_)(*this);
+  this->write_display_data();
+}
+
+int ST7920::get_width_internal() { return this->width_; }
+
+int ST7920::get_height_internal() { return this->height_; }
+
+size_t ST7920::get_buffer_length_() {
+  return size_t(this->get_width_internal()) * size_t(this->get_height_internal()) / 8u;
+}
+
+void HOT ST7920::draw_absolute_pixel_internal(int x, int y, Color color) {
+  if (x >= this->get_width_internal() || x < 0 || y >= this->get_height_internal() || y < 0) {
+    ESP_LOGW(TAG, "Position out of area: %dx%d", x, y);
+    return;
+  }
+  int width = this->get_width_internal() / 8u;
+  if (color.is_on()) {
+    this->buffer_[y * width + x / 8] |= (0x80 >> (x & 7));
+  } else {
+    this->buffer_[y * width + x / 8] &= ~(0x80 >> (x & 7));
+  }
+}
+
+void ST7920::display_init_() {
+  ESP_LOGD(TAG, "Initializing display...");
+  this->command_(LCD_BASIC);      // 8bit mode
+  this->command_(LCD_BASIC);      // 8bit mode
+  this->command_(LCD_CLS);        // clear screen
+  delay(12);                      // >10 ms delay
+  this->command_(LCD_ADDRINC);    // cursor increment right no shift
+  this->command_(LCD_DISPLAYON);  // D=1, C=0, B=0
+  this->command_(LCD_EXTEND);     // LCD_EXTEND);
+  this->command_(LCD_GFXMODE);    // LCD_GFXMODE);
+  this->write_display_data();
+}
+
+}  // namespace st7920
+}  // namespace esphome

esphome/components/st7920/st7920.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/components/display/display_buffer.h"
+#include "esphome/components/spi/spi.h"
+
+namespace esphome {
+namespace st7920 {
+
+class ST7920;
+
+using st7920_writer_t = std::function<void(ST7920 &)>;
+
+class ST7920 : public PollingComponent,
+               public display::DisplayBuffer,
+               public spi::SPIDevice<spi::BIT_ORDER_MSB_FIRST, spi::CLOCK_POLARITY_HIGH, spi::CLOCK_PHASE_TRAILING,
+                                     spi::DATA_RATE_1MHZ> {
+ public:
+  void set_writer(st7920_writer_t &&writer) { this->writer_local_ = writer; }
+  void set_height(uint16_t height) { this->height_ = height; }
+  void set_width(uint16_t width) { this->width_ = width; }
+
+  // ========== INTERNAL METHODS ==========
+  // (In most use cases you won't need these)
+  void setup() override;
+  void dump_config() override;
+  float get_setup_priority() const override;
+  void update() override;
+  void fill(Color color) override;
+  void write_display_data();
+
+ protected:
+  void draw_absolute_pixel_internal(int x, int y, Color color) override;
+  int get_height_internal() override;
+  int get_width_internal() override;
+  size_t get_buffer_length_();
+  void display_init_();
+  void command_(uint8_t value);
+  void data_(uint8_t value);
+  void send_(uint8_t type, uint8_t value);
+  void goto_xy_(uint16_t x, uint16_t y);
+  void start_transaction_();
+  void end_transaction_();
+
+  int16_t width_ = 128, height_ = 64;
+  optional<st7920_writer_t> writer_local_{};
+};
+
+}  // namespace st7920
+}  // namespace esphome

tests/test1.yaml

@@ -2038,6 +2038,14 @@ display:
     backlight_pin: GPIO4
     lambda: |-
       it.rectangle(0, 0, it.get_width(), it.get_height());
+  - platform: st7920
+    width: 128
+    height: 64
+    cs_pin:
+      number: GPIO23
+      inverted: true
+    lambda: |-
+      it.rectangle(0, 0, it.get_width(), it.get_height());
   - platform: st7735
     model: 'INITR_BLACKTAB'
     cs_pin: GPIO5