pw_graphics/pw_display_pico_st7789_spi/display.cc - pigweed/experimental - Git at Google

 // Copyright 2022 The Pigweed Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
 // use this file except in compliance with the License. You may obtain a copy of
 // the License at
 //
 //     https://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 // License for the specific language governing permissions and limitations under
 // the License.

 #include "pw_display/display.h"

 #include <stdio.h>
 #include <stdlib.h>

 #include <cinttypes>
 #include <cstdint>

 #include "hardware/pwm.h"
 #include "hardware/spi.h"
 #include "pico/stdlib.h"
 #include "pw_color/color.h"
 #include "pw_framebuffer/rgb565.h"

 namespace pw::display {

 namespace {

 // ST7789 Display Registers
 #define ST7789_SWRESET 0x01
 #define ST7789_TEOFF 0x34
 #define ST7789_TEON 0x35
 #define ST7789_MADCTL 0x36
 #define ST7789_COLMOD 0x3A
 #define ST7789_GCTRL 0xB7
 #define ST7789_VCOMS 0xBB
 #define ST7789_LCMCTRL 0xC0
 #define ST7789_VDVVRHEN 0xC2
 #define ST7789_VRHS 0xC3
 #define ST7789_VDVS 0xC4
 #define ST7789_FRCTRL2 0xC6
 #define ST7789_PWCTRL1 0xD0
 #define ST7789_PORCTRL 0xB2
 #define ST7789_GMCTRP1 0xE0
 #define ST7789_GMCTRN1 0xE1
 #define ST7789_INVOFF 0x20
 #define ST7789_SLPOUT 0x11
 #define ST7789_DISPON 0x29
 #define ST7789_GAMSET 0x26
 #define ST7789_DISPOFF 0x28
 #define ST7789_RAMWR 0x2C
 #define ST7789_INVON 0x21
 #define ST7789_CASET 0x2A
 #define ST7789_RASET 0x2B

 // MADCTL Bits (See page 215: MADCTL (36h): Memory Data Access Control)
 #define ST7789_MADCTL_ROW_ORDER 0b10000000
 #define ST7789_MADCTL_COL_ORDER 0b01000000
 #define ST7789_MADCTL_SWAP_XY 0b00100000
 #define ST7789_MADCTL_SCAN_ORDER 0b00010000
 #define ST7789_MADCTL_RGB_BGR 0b00001000
 #define ST7789_MADCTL_HORIZ_ORDER 0b00000100

 // Pico Display Pack 2 Pins
 // https://shop.pimoroni.com/products/pico-display-pack-2-0
 // --------------------------------------------------------
 constexpr int BACKLIGHT_EN = 20;
 // spi0 Pins
 #define SPI_PORT spi0
 constexpr int TFT_SCLK = 18;  // SPI0 SCK
 constexpr int TFT_MOSI = 19;  // SPI0 TX
 // Unconnected
 // const int TFT_MISO = 4;  // SPI0 RX
 constexpr int TFT_CS = 17;  // SPI0 CSn
 constexpr int TFT_DC = 16;  // GP16
 // Reset pin is connected to the Pico reset pin (RUN #30)
 // constexpr int TFT_RST = 19;

 // Pico Display Pack 2 Size
 constexpr int kDisplayWidth = 320;
 constexpr int kDisplayHeight = 240;
 constexpr int kDisplayDataSize = kDisplayWidth * kDisplayHeight;

 uint16_t framebuffer_data[kDisplayDataSize];

 // Pico Enviro+ Pack Pins are the same as Display Pack 2
 // https://shop.pimoroni.com/products/pico-enviro-pack
 // --------------------------------------------------------

 // Pico Enviro+ Pack Size
 // constexpr int kDisplayWidth = 240;
 // constexpr int kDisplayHeight = 240;
 // constexpr int kDisplayDataSize = kDisplayWidth * kDisplayHeight;

 // PicoSystem
 // https://shop.pimoroni.com/products/picosystem
 // --------------------------------------------------------
 // constexpr int BACKLIGHT_EN = 12;
 // #define SPI_PORT spi0
 // constexpr int TFT_SCLK = 6;  // SPI0 SCK
 // constexpr int TFT_MOSI = 7;  // SPI0 TX
 // Unconnected
 // const int TFT_MISO = 4;  // SPI0 RX
 // constexpr int TFT_CS = 5;  // SPI0 CSn
 // constexpr int TFT_DC = 9;  // GP16
 // constexpr int TFT_RST = 4;

 // SPI Functions
 // TODO(tonymd): move to pw_spi
 static inline void ChipSelectEnable() {
   asm volatile("nop \n nop \n nop");
   gpio_put(TFT_CS, 0);
   asm volatile("nop \n nop \n nop");
 }

 static inline void ChipSelectDisable() {
   asm volatile("nop \n nop \n nop");
   gpio_put(TFT_CS, 1);
   asm volatile("nop \n nop \n nop");
 }

 static inline void DataCommandEnable() {
   asm volatile("nop \n nop \n nop");
   gpio_put(TFT_DC, 0);
   asm volatile("nop \n nop \n nop");
 }

 static inline void DataCommandDisable() {
   asm volatile("nop \n nop \n nop");
   gpio_put(TFT_DC, 1);
   asm volatile("nop \n nop \n nop");
 }

 static void inline SPISendByte(uint8_t data) {
   ChipSelectEnable();
   DataCommandDisable();
   spi_write_blocking(SPI_PORT, &data, 1);
   ChipSelectDisable();
 }

 static void inline SPISendShort(uint16_t data) {
   ChipSelectEnable();
   DataCommandDisable();

   uint8_t shortBuffer[2];

   shortBuffer[0] = (uint8_t)(data >> 8);
   shortBuffer[1] = (uint8_t)data;

   spi_write_blocking(SPI_PORT, shortBuffer, 2);

   ChipSelectDisable();
 }

 static void inline SPISendCommand(uint8_t command) {
   // set data/command to command mode (low).
   DataCommandEnable();
   ChipSelectEnable();

   // send the command to the display.
   spi_write_blocking(SPI_PORT, &command, 1);

   // put the display back into data mode (high).
   DataCommandDisable();
   ChipSelectDisable();
 }

 static void inline SPISendCommand(uint8_t command,
                                   size_t data_length,
                                   const char* data) {
   // set data/command to command mode (low).
   DataCommandEnable();
   ChipSelectEnable();

   // send the command to the display.
   spi_write_blocking(SPI_PORT, &command, 1);

   // put the display back into data mode (high).
   DataCommandDisable();
   spi_write_blocking(SPI_PORT, (const uint8_t*)data, data_length);

   ChipSelectDisable();
 }

 }  // namespace

 void Init() {
   stdio_init_all();
   // TODO: This should be a facade
   setup_default_uart();

   uint actual_baudrate = spi_init(SPI_PORT, 62'500'000);
   // NOTE: If the display isn't working try a slower SPI baudrate:
   // uint actual_baudrate = spi_init(SPI_PORT, 31'250'000);

   // Set 8 bit SPI writes.
   spi_set_format(SPI_PORT, 8, (spi_cpol_t)1, (spi_cpha_t)1, SPI_MSB_FIRST);

   // Init backlight PWM
   pwm_config cfg = pwm_get_default_config();
   pwm_set_wrap(pwm_gpio_to_slice_num(BACKLIGHT_EN), 65535);
   pwm_init(pwm_gpio_to_slice_num(BACKLIGHT_EN), &cfg, true);
   gpio_set_function(BACKLIGHT_EN, GPIO_FUNC_PWM);
   // Full Brightness
   pwm_set_gpio_level(BACKLIGHT_EN, 65535);

   // Init Pico SPI
   // gpio_set_function(TFT_MISO, GPIO_FUNC_SPI);  // Unused
   gpio_set_function(TFT_SCLK, GPIO_FUNC_SPI);
   gpio_set_function(TFT_MOSI, GPIO_FUNC_SPI);

   gpio_init(TFT_CS);
   gpio_init(TFT_DC);
   // gpio_init(TFT_RST); // Unused

   gpio_set_dir(TFT_CS, GPIO_OUT);
   gpio_set_dir(TFT_DC, GPIO_OUT);
   // gpio_set_dir(TFT_RST, GPIO_OUT);  // Unused
   gpio_put(TFT_CS, 1);
   gpio_put(TFT_DC, 0);
   // gpio_put(TFT_RST, 0);  // Unused

   // Init Display
   SPISendCommand(ST7789_SWRESET);  // Software reset

   sleep_ms(150);

   SPISendCommand(ST7789_TEON);
   SPISendCommand(ST7789_COLMOD, 1, "\x05");

   SPISendCommand(ST7789_PORCTRL, 5, "\x0c\x0c\x00\x33\x33");
   SPISendCommand(ST7789_LCMCTRL, 1, "\x2c");
   SPISendCommand(ST7789_VDVVRHEN, 1, "\x01");
   SPISendCommand(ST7789_VRHS, 1, "\x12");
   SPISendCommand(ST7789_VDVS, 1, "\x20");
   SPISendCommand(ST7789_PWCTRL1, 2, "\xa4\xa1");
   SPISendCommand(ST7789_FRCTRL2, 1, "\x0f");

   SPISendCommand(ST7789_INVON);
   SPISendCommand(ST7789_SLPOUT);
   SPISendCommand(ST7789_DISPON);

   uint8_t madctl = 0;
   bool rotate_180 = false;

   if (kDisplayWidth == 240 && kDisplayHeight == 240) {
     // Column Address Set
     SPISendCommand(ST7789_CASET);
     SPISendShort(0);
     SPISendShort(kDisplayWidth - 1);
     // Page Address Set
     SPISendCommand(ST7789_RASET);
     SPISendShort(0);
     SPISendShort(kDisplayHeight - 1);
     // TODO: Figure out 240x240 square display MADCTL values for rotation.
     madctl = ST7789_MADCTL_HORIZ_ORDER;
   } else if (kDisplayWidth == 320 && kDisplayHeight == 240) {
     // Landscape drawing
     // Column Address Set
     SPISendCommand(ST7789_CASET);
     SPISendShort(0);
     SPISendShort(kDisplayWidth - 1);
     // Page Address Set
     SPISendCommand(ST7789_RASET);
     SPISendShort(0);
     SPISendShort(kDisplayHeight - 1);

     madctl = ST7789_MADCTL_COL_ORDER;
     if (rotate_180)
       madctl = ST7789_MADCTL_ROW_ORDER;

     madctl |= ST7789_MADCTL_SWAP_XY | ST7789_MADCTL_SCAN_ORDER;
   }

   SPISendCommand(ST7789_MADCTL, 1, (char*)&madctl);

   sleep_ms(50);
 }

 int GetWidth() { return kDisplayWidth; }
 int GetHeight() { return kDisplayHeight; }

 void SendDisplayWriteCommand() {
   uint8_t command = ST7789_RAMWR;
   // Switch to 8 bit writes.
   spi_set_format(SPI_PORT, 8, (spi_cpol_t)1, (spi_cpha_t)1, SPI_MSB_FIRST);
   DataCommandEnable();
   ChipSelectEnable();
   spi_write_blocking(SPI_PORT, &command, 1);
   DataCommandDisable();
   // Switch to 16 bit writes.
   spi_set_format(SPI_PORT, 16, (spi_cpol_t)1, (spi_cpha_t)1, SPI_MSB_FIRST);
 }

 void UpdatePixelDouble(pw::framebuffer::FramebufferRgb565* frame_buffer) {
   SendDisplayWriteCommand();

   uint16_t temp_row[kDisplayWidth];
   color_rgb565_t* pixel_data = frame_buffer->GetFramebufferData();
   for (int y = 0; y < frame_buffer->GetHeight(); y++) {
     // Populate this row with each pixel repeated twice
     for (int x = 0; x < frame_buffer->GetWidth(); x++) {
       temp_row[x * 2] = pixel_data[y * frame_buffer->GetWidth() + x];
       temp_row[(x * 2) + 1] = pixel_data[y * frame_buffer->GetHeight() + x];
     }
     // Send this row to the display twice.
     spi_write16_blocking(SPI_PORT, temp_row, kDisplayWidth);
     spi_write16_blocking(SPI_PORT, temp_row, kDisplayWidth);
   }

   ChipSelectDisable();
 }

 void Update(pw::framebuffer::FramebufferRgb565* frame_buffer) {
   SendDisplayWriteCommand();

   const uint16_t* pixel_data = frame_buffer->GetFramebufferData();
   spi_write16_blocking(SPI_PORT, pixel_data, kDisplayDataSize);
   // put the display back into data mode (high).
   ChipSelectDisable();
 }

 bool TouchscreenAvailable() { return false; }

 bool NewTouchEvent() { return false; }

 pw::coordinates::Vec3Int GetTouchPoint() {
   pw::coordinates::Vec3Int point;
   point.x = 0;
   point.y = 0;
   point.z = 0;
   return point;
 }

 Status InitFramebuffer(FramebufferRgb565* framebuffer) {
   framebuffer->SetFramebufferData(
       framebuffer_data, kDisplayWidth, kDisplayHeight);
   return OkStatus();
 }

 }  // namespace pw::display
	// Copyright 2022 The Pigweed Authors
	//
	// Licensed under the Apache License, Version 2.0 (the "License"); you may not
	// use this file except in compliance with the License. You may obtain a copy of
	// the License at
	//
	// https://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	// License for the specific language governing permissions and limitations under
	// the License.

	#include "pw_display/display.h"

	#include <stdio.h>
	#include <stdlib.h>

	#include <cinttypes>
	#include <cstdint>

	#include "hardware/pwm.h"
	#include "hardware/spi.h"
	#include "pico/stdlib.h"
	#include "pw_color/color.h"
	#include "pw_framebuffer/rgb565.h"

	namespace pw::display {

	namespace {

	// ST7789 Display Registers
	#define ST7789_SWRESET 0x01
	#define ST7789_TEOFF 0x34
	#define ST7789_TEON 0x35
	#define ST7789_MADCTL 0x36
	#define ST7789_COLMOD 0x3A
	#define ST7789_GCTRL 0xB7
	#define ST7789_VCOMS 0xBB
	#define ST7789_LCMCTRL 0xC0
	#define ST7789_VDVVRHEN 0xC2
	#define ST7789_VRHS 0xC3
	#define ST7789_VDVS 0xC4
	#define ST7789_FRCTRL2 0xC6
	#define ST7789_PWCTRL1 0xD0
	#define ST7789_PORCTRL 0xB2
	#define ST7789_GMCTRP1 0xE0
	#define ST7789_GMCTRN1 0xE1
	#define ST7789_INVOFF 0x20
	#define ST7789_SLPOUT 0x11
	#define ST7789_DISPON 0x29
	#define ST7789_GAMSET 0x26
	#define ST7789_DISPOFF 0x28
	#define ST7789_RAMWR 0x2C
	#define ST7789_INVON 0x21
	#define ST7789_CASET 0x2A
	#define ST7789_RASET 0x2B

	// MADCTL Bits (See page 215: MADCTL (36h): Memory Data Access Control)
	#define ST7789_MADCTL_ROW_ORDER 0b10000000
	#define ST7789_MADCTL_COL_ORDER 0b01000000
	#define ST7789_MADCTL_SWAP_XY 0b00100000
	#define ST7789_MADCTL_SCAN_ORDER 0b00010000
	#define ST7789_MADCTL_RGB_BGR 0b00001000
	#define ST7789_MADCTL_HORIZ_ORDER 0b00000100

	// Pico Display Pack 2 Pins
	// https://shop.pimoroni.com/products/pico-display-pack-2-0
	// --------------------------------------------------------
	constexpr int BACKLIGHT_EN = 20;
	// spi0 Pins
	#define SPI_PORT spi0
	constexpr int TFT_SCLK = 18; // SPI0 SCK
	constexpr int TFT_MOSI = 19; // SPI0 TX
	// Unconnected
	// const int TFT_MISO = 4; // SPI0 RX
	constexpr int TFT_CS = 17; // SPI0 CSn
	constexpr int TFT_DC = 16; // GP16
	// Reset pin is connected to the Pico reset pin (RUN #30)
	// constexpr int TFT_RST = 19;

	// Pico Display Pack 2 Size
	constexpr int kDisplayWidth = 320;
	constexpr int kDisplayHeight = 240;
	constexpr int kDisplayDataSize = kDisplayWidth * kDisplayHeight;

	uint16_t framebuffer_data[kDisplayDataSize];

	// Pico Enviro+ Pack Pins are the same as Display Pack 2
	// https://shop.pimoroni.com/products/pico-enviro-pack
	// --------------------------------------------------------

	// Pico Enviro+ Pack Size
	// constexpr int kDisplayWidth = 240;
	// constexpr int kDisplayHeight = 240;
	// constexpr int kDisplayDataSize = kDisplayWidth * kDisplayHeight;

	// PicoSystem
	// https://shop.pimoroni.com/products/picosystem
	// --------------------------------------------------------
	// constexpr int BACKLIGHT_EN = 12;
	// #define SPI_PORT spi0
	// constexpr int TFT_SCLK = 6; // SPI0 SCK
	// constexpr int TFT_MOSI = 7; // SPI0 TX
	// Unconnected
	// const int TFT_MISO = 4; // SPI0 RX
	// constexpr int TFT_CS = 5; // SPI0 CSn
	// constexpr int TFT_DC = 9; // GP16
	// constexpr int TFT_RST = 4;

	// SPI Functions
	// TODO(tonymd): move to pw_spi
	static inline void ChipSelectEnable() {
	asm volatile("nop \n nop \n nop");
	gpio_put(TFT_CS, 0);
	asm volatile("nop \n nop \n nop");
	}

	static inline void ChipSelectDisable() {
	asm volatile("nop \n nop \n nop");
	gpio_put(TFT_CS, 1);
	asm volatile("nop \n nop \n nop");
	}

	static inline void DataCommandEnable() {
	asm volatile("nop \n nop \n nop");
	gpio_put(TFT_DC, 0);
	asm volatile("nop \n nop \n nop");
	}

	static inline void DataCommandDisable() {
	asm volatile("nop \n nop \n nop");
	gpio_put(TFT_DC, 1);
	asm volatile("nop \n nop \n nop");
	}

	static void inline SPISendByte(uint8_t data) {
	ChipSelectEnable();
	DataCommandDisable();
	spi_write_blocking(SPI_PORT, &data, 1);
	ChipSelectDisable();
	}

	static void inline SPISendShort(uint16_t data) {
	ChipSelectEnable();
	DataCommandDisable();

	uint8_t shortBuffer[2];

	shortBuffer[0] = (uint8_t)(data >> 8);
	shortBuffer[1] = (uint8_t)data;

	spi_write_blocking(SPI_PORT, shortBuffer, 2);

	ChipSelectDisable();
	}

	static void inline SPISendCommand(uint8_t command) {
	// set data/command to command mode (low).
	DataCommandEnable();
	ChipSelectEnable();

	// send the command to the display.
	spi_write_blocking(SPI_PORT, &command, 1);

	// put the display back into data mode (high).
	DataCommandDisable();
	ChipSelectDisable();
	}

	static void inline SPISendCommand(uint8_t command,
	size_t data_length,
	const char* data) {
	// set data/command to command mode (low).
	DataCommandEnable();
	ChipSelectEnable();

	// send the command to the display.
	spi_write_blocking(SPI_PORT, &command, 1);

	// put the display back into data mode (high).
	DataCommandDisable();
	spi_write_blocking(SPI_PORT, (const uint8_t*)data, data_length);

	ChipSelectDisable();
	}

	} // namespace

	void Init() {
	stdio_init_all();
	// TODO: This should be a facade
	setup_default_uart();

	uint actual_baudrate = spi_init(SPI_PORT, 62'500'000);
	// NOTE: If the display isn't working try a slower SPI baudrate:
	// uint actual_baudrate = spi_init(SPI_PORT, 31'250'000);

	// Set 8 bit SPI writes.
	spi_set_format(SPI_PORT, 8, (spi_cpol_t)1, (spi_cpha_t)1, SPI_MSB_FIRST);

	// Init backlight PWM
	pwm_config cfg = pwm_get_default_config();
	pwm_set_wrap(pwm_gpio_to_slice_num(BACKLIGHT_EN), 65535);
	pwm_init(pwm_gpio_to_slice_num(BACKLIGHT_EN), &cfg, true);
	gpio_set_function(BACKLIGHT_EN, GPIO_FUNC_PWM);
	// Full Brightness
	pwm_set_gpio_level(BACKLIGHT_EN, 65535);

	// Init Pico SPI
	// gpio_set_function(TFT_MISO, GPIO_FUNC_SPI); // Unused
	gpio_set_function(TFT_SCLK, GPIO_FUNC_SPI);
	gpio_set_function(TFT_MOSI, GPIO_FUNC_SPI);

	gpio_init(TFT_CS);
	gpio_init(TFT_DC);
	// gpio_init(TFT_RST); // Unused

	gpio_set_dir(TFT_CS, GPIO_OUT);
	gpio_set_dir(TFT_DC, GPIO_OUT);
	// gpio_set_dir(TFT_RST, GPIO_OUT); // Unused
	gpio_put(TFT_CS, 1);
	gpio_put(TFT_DC, 0);
	// gpio_put(TFT_RST, 0); // Unused

	// Init Display
	SPISendCommand(ST7789_SWRESET); // Software reset

	sleep_ms(150);

	SPISendCommand(ST7789_TEON);
	SPISendCommand(ST7789_COLMOD, 1, "\x05");

	SPISendCommand(ST7789_PORCTRL, 5, "\x0c\x0c\x00\x33\x33");
	SPISendCommand(ST7789_LCMCTRL, 1, "\x2c");
	SPISendCommand(ST7789_VDVVRHEN, 1, "\x01");
	SPISendCommand(ST7789_VRHS, 1, "\x12");
	SPISendCommand(ST7789_VDVS, 1, "\x20");
	SPISendCommand(ST7789_PWCTRL1, 2, "\xa4\xa1");
	SPISendCommand(ST7789_FRCTRL2, 1, "\x0f");

	SPISendCommand(ST7789_INVON);
	SPISendCommand(ST7789_SLPOUT);
	SPISendCommand(ST7789_DISPON);

	uint8_t madctl = 0;
	bool rotate_180 = false;

	if (kDisplayWidth == 240 && kDisplayHeight == 240) {
	// Column Address Set
	SPISendCommand(ST7789_CASET);
	SPISendShort(0);
	SPISendShort(kDisplayWidth - 1);
	// Page Address Set
	SPISendCommand(ST7789_RASET);
	SPISendShort(0);
	SPISendShort(kDisplayHeight - 1);
	// TODO: Figure out 240x240 square display MADCTL values for rotation.
	madctl = ST7789_MADCTL_HORIZ_ORDER;
	} else if (kDisplayWidth == 320 && kDisplayHeight == 240) {
	// Landscape drawing
	// Column Address Set
	SPISendCommand(ST7789_CASET);
	SPISendShort(0);
	SPISendShort(kDisplayWidth - 1);
	// Page Address Set
	SPISendCommand(ST7789_RASET);
	SPISendShort(0);
	SPISendShort(kDisplayHeight - 1);

	madctl = ST7789_MADCTL_COL_ORDER;
	if (rotate_180)
	madctl = ST7789_MADCTL_ROW_ORDER;

	madctl \|= ST7789_MADCTL_SWAP_XY \| ST7789_MADCTL_SCAN_ORDER;
	}

	SPISendCommand(ST7789_MADCTL, 1, (char*)&madctl);

	sleep_ms(50);
	}

	int GetWidth() { return kDisplayWidth; }
	int GetHeight() { return kDisplayHeight; }

	void SendDisplayWriteCommand() {
	uint8_t command = ST7789_RAMWR;
	// Switch to 8 bit writes.
	spi_set_format(SPI_PORT, 8, (spi_cpol_t)1, (spi_cpha_t)1, SPI_MSB_FIRST);
	DataCommandEnable();
	ChipSelectEnable();
	spi_write_blocking(SPI_PORT, &command, 1);
	DataCommandDisable();
	// Switch to 16 bit writes.
	spi_set_format(SPI_PORT, 16, (spi_cpol_t)1, (spi_cpha_t)1, SPI_MSB_FIRST);
	}

	void UpdatePixelDouble(pw::framebuffer::FramebufferRgb565* frame_buffer) {
	SendDisplayWriteCommand();

	uint16_t temp_row[kDisplayWidth];
	color_rgb565_t* pixel_data = frame_buffer->GetFramebufferData();
	for (int y = 0; y < frame_buffer->GetHeight(); y++) {
	// Populate this row with each pixel repeated twice
	for (int x = 0; x < frame_buffer->GetWidth(); x++) {
	temp_row[x * 2] = pixel_data[y * frame_buffer->GetWidth() + x];
	temp_row[(x * 2) + 1] = pixel_data[y * frame_buffer->GetHeight() + x];
	}
	// Send this row to the display twice.
	spi_write16_blocking(SPI_PORT, temp_row, kDisplayWidth);
	spi_write16_blocking(SPI_PORT, temp_row, kDisplayWidth);
	}

	ChipSelectDisable();
	}

	void Update(pw::framebuffer::FramebufferRgb565* frame_buffer) {
	SendDisplayWriteCommand();

	const uint16_t* pixel_data = frame_buffer->GetFramebufferData();
	spi_write16_blocking(SPI_PORT, pixel_data, kDisplayDataSize);
	// put the display back into data mode (high).
	ChipSelectDisable();
	}

	bool TouchscreenAvailable() { return false; }

	bool NewTouchEvent() { return false; }

	pw::coordinates::Vec3Int GetTouchPoint() {
	pw::coordinates::Vec3Int point;
	point.x = 0;
	point.y = 0;
	point.z = 0;
	return point;
	}

	Status InitFramebuffer(FramebufferRgb565* framebuffer) {
	framebuffer->SetFramebufferData(
	framebuffer_data, kDisplayWidth, kDisplayHeight);
	return OkStatus();
	}

	} // namespace pw::display