ESP32-WROVER-KIT

Wrover-Kit

The ESP32-WROVER-KIT is a development board for the ESP32-WROVER module. It features a nice display and a lot of expansion headers.

The espp::WroverKit component provides a singleton hardware abstraction for initializing the display subsystems.

API Reference

Header File

components/wrover-kit/include/wrover-kit.hpp

Classes

class WroverKit : public espp::BaseComponent 

The WroverKit class provides an interface to the ESP32-WROVER-KIT ESP32 development board.

The class provides access to the following features:

Display

The class is a singleton and can be accessed using the get() method.

Example

  espp::WroverKit &wrover = espp::WroverKit::get();
  wrover.set_log_level(espp::Logger::Verbosity::INFO);

  // initialize the LCD
  if (!wrover.initialize_lcd()) {
    logger.error("Failed to initialize LCD!");
    return;
  }
  // set the pixel buffer to be 50 lines high
  static constexpr size_t pixel_buffer_size = wrover.lcd_width() * 50;
  // initialize the LVGL display for the wrover-kit
  if (!wrover.initialize_display(pixel_buffer_size)) {
    logger.error("Failed to initialize display!");
    return;
  }

  // create the GUI: builds the UI (label, circle layer) and starts the task
  // which updates LVGL. All of its public methods are thread-safe, so the
  // button callback and drawing loop below can call them directly.
  static Gui gui({.log_level = espp::Logger::Verbosity::INFO});
  gui.set_label_text("Drawing circles to the screen.");

  // initialize the button, which we'll use to cycle the rotation of the display
  espp::Button button(espp::Button::Config{
      .name = "Boot Button",
      .interrupt_config =
          espp::Interrupt::PinConfig{.gpio_num = GPIO_NUM_0,
                                     .callback =
                                         [](const auto &event) {
                                           if (event.active) {
                                             gui.next_rotation();
                                           }
                                         },
                                     .active_level = espp::Interrupt::ActiveLevel::LOW,
                                     .interrupt_type = espp::Interrupt::Type::ANY_EDGE,
                                     .pullup_enabled = false,
                                     .pulldown_enabled = false},
  });

  // set the display brightness to be 75%
  wrover.brightness(75.0f);

  while (true) {
    auto start = esp_timer_get_time();
    // if there are 10 circles on the screen, clear them
    if (gui.circle_count() >= Gui::MAX_CIRCLES) {
      gui.clear_circles();
    } else {
      // draw a circle of circles on the screen (just draw the next circle)
      int middle_x = wrover.rotated_display_width() / 2;
      int middle_y = wrover.rotated_display_height() / 2;
      static constexpr int radius = 50;
      float angle = gui.circle_count() * 2.0f * std::numbers::pi_v<float> / Gui::MAX_CIRCLES;
      int x = middle_x + radius * std::cos(angle);
      int y = middle_y + radius * std::sin(angle);
      gui.draw_circle(x, y, 10);
    }
    auto end = esp_timer_get_time();
    auto elapsed = end - start;
    std::this_thread::sleep_for(100ms - std::chrono::microseconds(elapsed));
  }

Public Types

using Pixel = lv_color16_t: Alias for the pixel type used by the wrover-kit display.

using DisplayDriver = espp::Ili9341 : Alias for the display driver.

Public Functions

bool initialize_lcd()

Initialize the LCD (low level display driver)

Returns:: true if the LCD was successfully initialized, false otherwise

bool initialize_display(size_t pixel_buffer_size)

Initialize the display (lvgl display driver)

Note

This will also allocate two full frame buffers in the SPIRAM

Parameters:: pixel_buffer_size – The size of the pixel buffer
Returns:: true if the display was successfully initialized, false otherwise

size_t rotated_display_width() const

Get the display width in pixels, according to the current orientation

Returns:: The display width in pixels, according to the current orientation

size_t rotated_display_height() const

Get the display height in pixels, according to the current orientation

Returns:: The display height in pixels, according to the current orientation

std::shared_ptr<Display<Pixel>> display() const

Get a shared pointer to the display

Returns:: A shared pointer to the display

inline const std::shared_ptr<DisplayDriver> &display_driver() const

Get a shared pointer to the low-level display driver

Returns:: A shared pointer to the display driver

void brightness(float brightness)

Set the brightness of the backlight

Note

This function will only work after initialize_lcd() has been called

Parameters:: brightness – The brightness of the backlight as a percentage (0 - 100)

float brightness() const

Get the brightness of the backlight

Note

This function will only work after initialize_lcd() has been called

Returns:: The brightness of the backlight as a percentage (0 - 100)

Pixel *vram0() const

Get the VRAM 0 pointer (DMA memory used by LVGL)

Note

This is the memory used by LVGL for rendering

Note

This is null unless initialize_display() has been called

Returns:: The VRAM 0 pointer

Pixel *vram1() const

Get the VRAM 1 pointer (DMA memory used by LVGL)

Note

This is the memory used by LVGL for rendering

Note

This is null unless initialize_display() has been called

Returns:: The VRAM 1 pointer

uint8_t *frame_buffer0() const

Get the frame buffer 0 pointer

Note

This memory is designed to be used by the application developer and is provided as a convenience. It is not used by the display driver.

Note

This is null unless initialize_display() has been called

Returns:: The frame buffer 0 pointer

uint8_t *frame_buffer1() const

Get the frame buffer 1 pointer

Note

This memory is designed to be used by the application developer and is provided as a convenience. It is not used by the display driver.

Note

This is null unless initialize_display() has been called

Returns:: The frame buffer 1 pointer

void write_lcd_frame(const uint16_t x, const uint16_t y, const uint16_t width, const uint16_t height, uint8_t *data)

Write a frame to the LCD

Note

This method queues the data to be written to the LCD, only blocking if there is an ongoing SPI transaction

Parameters:

x – The x coordinate
y – The y coordinate
width – The width of the frame, in pixels
height – The height of the frame, in pixels
data – The data to write

void write_lcd_lines(int xs, int ys, int xe, int ye, const uint8_t *data, uint32_t user_data)

Write lines to the LCD

Note

This method queues the panel transfer asynchronously and may return before the write has completed.

Parameters:

xs – The x start coordinate
ys – The y start coordinate
xe – The x end coordinate
ye – The y end coordinate
data – The data to write
user_data – User data to pass to the SPI transaction callback

inline const std::string &get_name() const

Get the name of the component

Note

This is the tag of the logger

Returns:: A const reference to the name of the component

inline void set_log_tag(const std::string_view &tag)

Set the tag for the logger

Parameters:: tag – The tag to use for the logger

inline espp::Logger::Verbosity get_log_level() const

Get the log level for the logger

See also

Logger::Verbosity

See also

Logger::set_verbosity

Returns:: The verbosity level of the logger

inline void set_log_level(espp::Logger::Verbosity level)

Set the log level for the logger

See also

Logger::Verbosity

See also

Logger::set_verbosity

Parameters:: level – The verbosity level to use for the logger

inline void set_log_verbosity(espp::Logger::Verbosity level)

Set the log verbosity for the logger

See also

set_log_level

See also

Logger::Verbosity

See also

Logger::set_verbosity

Note

This is a convenience method that calls set_log_level

Parameters:: level – The verbosity level to use for the logger

inline espp::Logger::Verbosity get_log_verbosity() const

Get the log verbosity for the logger

See also

get_log_level

See also

Logger::Verbosity

See also

Logger::get_verbosity

Note

This is a convenience method that calls get_log_level

Returns:: The verbosity level of the logger

inline void set_log_rate_limit(std::chrono::duration<float> rate_limit)

Set the rate limit for the logger

See also

Logger::set_rate_limit

Note

Only calls to the logger that have _rate_limit suffix will be rate limited

Parameters:: rate_limit – The rate limit to use for the logger

Public Static Functions

static inline WroverKit &get()

Access the singleton instance of the WroverKit class.

Returns:: Reference to the singleton instance of the WroverKit class

static inline constexpr size_t lcd_width()

Get the width of the LCD in pixels

Returns:: The width of the LCD in pixels

static inline constexpr size_t lcd_height()

Get the height of the LCD in pixels

Returns:: The height of the LCD in pixels

static inline constexpr auto get_lcd_dc_gpio()

Get the GPIO pin for the LCD data/command signal

Returns:: The GPIO pin for the LCD data/command signal

Public Static Attributes

static constexpr size_t SPI_MAX_TRANSFER_BYTES = SPI_LL_DMA_MAX_BIT_LEN / 8: Maximum number of bytes that can be transferred in a single SPI transaction to the Display. 2MB on ESP32.

struct TouchpadData

The data structure for the touchpad.

Public Functions

bool operator==(const TouchpadData &rhs) const = default

Compare two TouchpadData objects for equality.

Parameters:: rhs – The right hand side of the comparison
Returns:: true if the two TouchpadData objects are equal, false otherwise

Public Members

uint8_t num_touch_points = 0: The number of touch points.

uint16_t x = 0: The x coordinate.

uint16_t y = 0: The y coordinate.

uint8_t btn_state = 0: The button state (0 = button released, 1 = button pressed)