lcd touch screen s3 free sample

Knowledge of cell phone parts:Because of the assembled Lcd material are different. There are several kinds of quality for Samsung Lcd complete. Please tell us which quality you prefer.

Knowledge of cell phone parts:Because of the assembled Lcd material are different. There are several kinds of quality for Samsung Lcd complete. Please tell us which quality you prefer.

ESP chips can generate various kinds of timings that needed by common LCDs on the market, like SPI LCD, I80 LCD (a.k.a Intel 8080 parallel LCD), RGB/SRGB LCD, I2C LCD, etc. The esp_lcd component is officially to support those LCDs with a group of universal APIs across chips.

In esp_lcd, an LCD panel is represented by esp_lcd_panel_handle_t, which plays the role of an abstract frame buffer, regardless of the frame memory is allocated inside ESP chip or in external LCD controller. Based on the location of the frame buffer and the hardware connection interface, the LCD panel drivers are mainly grouped into the following categories:

Controller based LCD driver involves multiple steps to get a panel handle, like bus allocation, IO device registration and controller driver install. The frame buffer is located in the controller’s internal GRAM (Graphical RAM). ESP-IDF provides only a limited number of LCD controller drivers out of the box (e.g. ST7789, SSD1306), More Controller Based LCD Drivers are maintained in the Espressif Component Registry _.

RGB Interfaced LCD - is based on a group of specific synchronous signals indicating where to start and stop a frame. The frame buffer is allocated on the ESP side. The driver install steps are much simplified because we don’t need to install any IO interface driver in this case.

LCD Panel IO Operations - provides a set of APIs to operate the LCD panel, like turning on/off the display, setting the orientation, etc. These operations are common for either controller-based LCD panel driver or RGB LCD panel driver.

esp_lcd_panel_io_spi_config_t::dc_gpio_num: Sets the gpio number for the DC signal line (some LCD calls this RS line). The LCD driver will use this GPIO to switch between sending command and sending data.

esp_lcd_panel_io_spi_config_t::cs_gpio_num: Sets the gpio number for the CS signal line. The LCD driver will use this GPIO to select the LCD chip. If the SPI bus only has one device attached (i.e. this LCD), you can set the gpio number to -1 to occupy the bus exclusively.

esp_lcd_panel_io_spi_config_t::pclk_hz sets the frequency of the pixel clock, in Hz. The value should not exceed the range recommended in the LCD spec.

esp_lcd_panel_io_spi_config_t::spi_mode sets the SPI mode. The LCD driver will use this mode to communicate with the LCD. For the meaning of the SPI mode, please refer to the SPI Master API doc.

esp_lcd_panel_io_spi_config_t::lcd_cmd_bits and esp_lcd_panel_io_spi_config_t::lcd_param_bits set the bit width of the command and parameter that recognized by the LCD controller chip. This is chip specific, you should refer to your LCD spec in advance.

esp_lcd_panel_io_spi_config_t::trans_queue_depth sets the depth of the SPI transaction queue. A bigger value means more transactions can be queued up, but it also consumes more memory.

Install the LCD controller driver. The LCD controller driver is responsible for sending the commands and parameters to the LCD controller chip. In this step, you need to specify the SPI IO device handle that allocated in the last step, and some panel specific configurations:

esp_lcd_panel_dev_config_t::bits_per_pixel sets the bit width of the pixel color data. The LCD driver will use this value to calculate the number of bytes to send to the LCD controller chip.

esp_lcd_panel_io_i2c_config_t::dev_addr sets the I2C device address of the LCD controller chip. The LCD driver will use this address to communicate with the LCD controller chip.

esp_lcd_panel_io_i2c_config_t::lcd_cmd_bits and esp_lcd_panel_io_i2c_config_t::lcd_param_bits set the bit width of the command and parameter that recognized by the LCD controller chip. This is chip specific, you should refer to your LCD spec in advance.

Install the LCD controller driver. The LCD controller driver is responsible for sending the commands and parameters to the LCD controller chip. In this step, you need to specify the I2C IO device handle that allocated in the last step, and some panel specific configurations:

esp_lcd_panel_dev_config_t::bits_per_pixel sets the bit width of the pixel color data. The LCD driver will use this value to calculate the number of bytes to send to the LCD controller chip.

esp_lcd_i80_bus_config_t::data_gpio_nums is the array of the GPIO number of the data bus. The number of GPIOs should be equal to the esp_lcd_i80_bus_config_t::bus_width value.

esp_lcd_panel_io_i80_config_t::pclk_hz sets the pixel clock frequency in Hz. Higher pixel clock frequency will result in higher refresh rate, but may cause flickering if the DMA bandwidth is not sufficient or the LCD controller chip does not support high pixel clock frequency.

esp_lcd_panel_io_i80_config_t::lcd_cmd_bits and esp_lcd_panel_io_i80_config_t::lcd_param_bits set the bit width of the command and parameter that recognized by the LCD controller chip. This is chip specific, you should refer to your LCD spec in advance.

esp_lcd_panel_io_i80_config_t::trans_queue_depth sets the maximum number of transactions that can be queued in the LCD IO device. A bigger value means more transactions can be queued up, but it also consumes more memory.

Install the LCD controller driver. The LCD controller driver is responsible for sending the commands and parameters to the LCD controller chip. In this step, you need to specify the I80 IO device handle that allocated in the last step, and some panel specific configurations:

esp_lcd_panel_dev_config_t::bits_per_pixel sets the bit width of the pixel color data. The LCD driver will use this value to calculate the number of bytes to send to the LCD controller chip.

esp_lcd_panel_dev_config_t::reset_gpio_num sets the GPIO number of the reset pin. If the LCD controller chip does not have a reset pin, you can set this value to -1.

More LCD panel drivers and touch drivers are available in IDF Component Registry. The list of available and planned drivers with links is in this table.

esp_lcd_rgb_panel_config_t::clk_src selects the clock source for the RGB LCD controller. The available clock sources are listed in lcd_clock_source_t.

esp_lcd_rgb_panel_config_t::bits_per_pixel set the number of bits per pixel. This is different from esp_lcd_rgb_panel_config_t::data_width. By default, if you set this field to 0, the driver will automatically adjust the bpp to the esp_lcd_rgb_panel_config_t::data_width. But in some cases, these two value must be different. For example, a Serial RGB interface LCD only needs 8 data lines, but the color width can reach to RGB888, i.e. the esp_lcd_rgb_panel_config_t::bits_per_pixel should be set to 24.

esp_lcd_rgb_panel_config_t::sram_trans_align and esp_lcd_rgb_panel_config_t::psram_trans_align set the alignment of the allocated frame buffer. Internally, the DMA transfer ability will adjust against these alignment values. A higher alignment value can lead to a bigger DMA burst size. Please note, the alignment value must be a power of 2.

esp_lcd_rgb_panel_config_t::bounce_buffer_size_px set the size of bounce buffer. This is only necessary for a so-called “bounce buffer” mode. Please refer to Bounce Buffer with Single PSRAM Frame Buffer for more information.

esp_lcd_rgb_panel_config_t::timings sets the LCD panel specific timing parameters. All required parameters are listed in the esp_lcd_rgb_timing_t, including the LCD resolution and blanking porches. Please fill them according to the datasheet of your LCD.

esp_lcd_rgb_panel_config_t::fb_in_psram sets whether to allocate the frame buffer from PSRAM or not. Please refer to Single Frame Buffer in PSRAM for more information.

esp_lcd_rgb_panel_config_t::num_fbs sets the number of frame buffers allocated by the driver. For backward compatibility, 0 means to allocate one frame buffer. Please use esp_lcd_rgb_panel_config_t::no_fb if you don’t want to allocate any frame buffer.

Most of the time, the RGB LCD driver should maintain at least one screen sized frame buffer. According to the number and location of the frame buffer, the driver provides several different buffer modes.

This is the default and simplest and you don’t have to specify flags or bounce buffer options. A frame buffer is allocated from the internal memory. The frame data is read out by DMA to the LCD verbatim. It needs no CPU intervention to function, but it has the downside that it uses up a fair bit of the limited amount of internal memory.

If you have PSRAM and want to store the frame buffer there rather than in the limited internal memory, the LCD peripheral will use EDMA to fetch frame data directly from the PSRAM, bypassing the internal cache. You can enable this feature by setting the esp_lcd_rgb_panel_config_t::fb_in_psram to true. The downside of this is that when both the CPU as well as EDMA need access to the PSRAM, the bandwidth will be shared between them, that is, EDMA gets half and the CPUs get the other half. If there’re other peripherals using EDMA as well, with a high enough pixel clock this can lead to starvation of the LCD peripheral, leading to display corruption. However, if the pixel clock is low enough for this not to be an issue, this is a solution that uses almost no CPU intervention.

The PSRAM shares the same SPI bus with the main Flash (the one stores your firmware binary). At one time, there only be one consumer of the SPI bus. When you also use the main flash to serve your file system (e.g. SPIFFS), the bandwidth of the underlying SPI bus will also be shared, leading to display corruption. You can use esp_lcd_rgb_panel_set_pclk() to update the pixel clock frequency to a lower value.

To avoid tearing effect, using two screen sized frame buffers is the easiest approach. In this mode, the frame buffer can only be allocated from PSRAM, because of the limited internal memory. The frame buffer that the CPU write to and the frame buffer that the EDMA read from are guaranteed to be different and independent. The EDMA will only switch between the two frame buffers when the previous write operation is finished and the current frame has been sent to the LCD. The downside of this mode is that, you have to maintain the synchronization between the two frame buffers.

This mode allocates two so-called bounce buffers from the internal memory, and a main frame buffer that is still in PSRAM. This mode is selected by setting the esp_lcd_rgb_panel_config_t::fb_in_psram flag and additionally specifying a non-zero esp_lcd_rgb_panel_config_t::bounce_buffer_size_px value. The bounce buffers only need to be large enough to hold a few lines of display data, which is significantly less than the main frame buffer. The LCD peripheral will use DMA to read data from one of the bounce buffers, and meanwhile an interrupt routine will use the CPU DCache to copy data from the main PSRAM frame buffer into the other bounce buffer. Once the LCD peripheral has finished reading the bounce buffer, the two buffers change place and the CPU can fill the others. The advantage of this mode is that, you can achieve higher pixel clock frequency. As the bounce buffers are larger than the FIFOs in the EDMA path, this method is also more robust against short bandwidth spikes. The downside is a major increase in CPU use and the LCD CAN’T work if we disable the cache of the external memory, via e.g. OTA or NVS write to the main flash.

Note that this mode also allows for a esp_lcd_rgb_panel_config_t::bb_invalidate_cache flag to be set. Enabling this frees up the cache lines after they’re used to read out the frame buffer data from PSRAM, but it may lead to slight corruption if the other core writes data to the frame buffer at the exact time the cache lines are freed up. (Technically, a write to the frame buffer can be ignored if it falls between the cache writeback and the cache invalidate calls.)

This mode is similar to the Bounce Buffer with Single PSRAM Frame Buffer, but there is no PSRAM frame buffer initialized by the LCD driver. Instead, the user supplies a callback function that is responsible for filling the bounce buffers. As this driver does not care where the written pixels come from, this allows for the callback doing e.g. on-the-fly conversion from a smaller, 8-bit-per-pixel PSRAM frame buffer to an 16-bit LCD, or even procedurally-generated frame-buffer-less graphics. This option is selected by setting the esp_lcd_rgb_panel_config_t::no_fb flag and supplying a esp_lcd_rgb_panel_config_t::bounce_buffer_size_px value. And then register the esp_lcd_rgb_panel_event_callbacks_t::on_bounce_empty callback by calling esp_lcd_rgb_panel_register_event_callbacks().

It should never happen in a well-designed embedded application, but it can in theory be possible that the DMA cannot deliver data as fast as the LCD consumes it. In the ESP32-S3 hardware, this leads to the LCD simply outputting dummy bytes while DMA waits for data. If we were to run DMA in a stream fashion, this would mean a de-sync between the LCD address the DMA reads the data for and the LCD address the LCD peripheral thinks it outputs data for, leading to a permanently shifted image.

In order to stop this from happening, you can either enable the CONFIG_LCD_RGB_RESTART_IN_VSYNC option, so the driver can restart the DMA in the VBlank interrupt automatically or call esp_lcd_rgb_panel_restart() to restart the DMA manually. Note esp_lcd_rgb_panel_restart() doesn’t restart the DMA immediately, the DMA will still be restarted in the next VSYNC event.

esp_lcd_panel_draw_bitmap() is the most significant function, that will do the magic to draw the user provided color buffer to the LCD screen, where the draw window is also configurable.

Commands sent by this function are short, so they are sent using polling transactions. The function does not return before the command transfer is completed. If any queued transactions sent by esp_lcd_panel_io_tx_color() are still pending when this function is called, this function will wait until they are finished and the queue is empty before sending the command(s).

Commands sent by this function are short, so they are sent using polling transactions. The function does not return before the command transfer is completed. If any queued transactions sent by esp_lcd_panel_io_tx_color() are still pending when this function is called, this function will wait until they are finished and the queue is empty before sending the command(s).

This function can be useful when the LCD controller is out of sync with the DMA because of insufficient bandwidth. To save the screen from a permanent shift, you can call this function to restart the LCD DMA.

If CONFIG_LCD_RGB_RESTART_IN_VSYNC is enabled, you don’t need to call this function manually, because the restart job will be done automatically in the VSYNC event handler.

Number of screen-sized frame buffers that allocated by the driver. By default (set to either 0 or 1) only one frame buffer will be used. Maximum number of buffers are 3

If this flag is enabled, the host only refresh the frame buffer when esp_lcd_panel_draw_bitmap is called. This is useful when the LCD screen has a GRAM and can refresh the LCD by itself.

An excellent new compatible library is available which can render TrueType fonts on a TFT screen (or into a sprite). This has been developed by takkaO and is available here. I have been reluctant to support yet another font format but this is an amazing library which is very easy to use. It provides access to compact font files, with fully scaleable anti-aliased glyphs. Left, middle and right justified text can also be printed to the screen. I have added TFT_eSPI specific examples to the OpenFontRender library and tested on RP2040 and ESP32 processors, however the ESP8266 does not have sufficient RAM. Here is a demo screen where a single 12kbyte font file binary was used to render fully anti-aliased glyphs of gradually increasing size on a 320x480 TFT screen:

Support has been added in v2.4.70 for the RP2040 with 16 bit parallel displays. This has been tested and the screen update performance is very good (4ms to clear 320 x 480 screen with HC8357C). The use of the RP2040 PIO makes it easy to change the write cycle timing for different displays. DMA with 16 bit transfers is also supported.

Support for the ESP32-S2, ESP32-S3 and ESP32-C3 has been added (DMA not supported at the moment). Tested with v2.0.3 RC1 of the ESP32 board package. Example setups:

The RP2040 8 bit parallel interface uses the PIO. The PIO now manages the "setWindow" and "block fill" actions, releasing the processor for other tasks when areas of the screen are being filled with a colour. The PIO can optionally be used for SPI interface displays if #define RP2040_PIO_SPI is put in the setup file. Touch screens and pixel read operations are not supported when the PIO interface is used.

The library supports some TFT displays designed for the Raspberry Pi (RPi) that are based on a ILI9486 or ST7796 driver chip with a 480 x 320 pixel screen. The ILI9486 RPi display must be of the Waveshare design and use a 16 bit serial interface based on the 74HC04, 74HC4040 and 2 x 74HC4094 logic chips. Note that due to design variations between these displays not all RPi displays will work with this library, so purchasing a RPi display of these types solely for use with this library is NOT recommended.

Some displays permit the internal TFT screen RAM to be read, a few of the examples use this feature. The TFT_Screen_Capture example allows full screens to be captured and sent to a PC, this is handy to create program documentation.

A Sprite is notionally an invisible graphics screen that is kept in the processors RAM. Graphics can be drawn into the Sprite just as they can be drawn directly to the screen. Once the Sprite is completed it can be plotted onto the screen in any position. If there is sufficient RAM then the Sprite can be the same size as the screen and used as a frame buffer. Sprites by default use 16 bit colours, the bit depth can be set to 8 bits (256 colours) , or 1 bit (any 2 colours) to reduce the RAM needed. On an ESP8266 the largest 16 bit colour Sprite that can be created is about 160x128 pixels, this consumes 40Kbytes of RAM. On an ESP32 the workspace RAM is more limited than the datasheet implies so a 16 bit colour Sprite is limited to about 200x200 pixels (~80Kbytes), an 8 bit sprite to 320x240 pixels (~76kbytes). A 1 bit per pixel Sprite requires only 9600 bytes for a full 320 x 240 screen buffer, this is ideal for supporting use with 2 colour bitmap fonts.

One or more sprites can be created, a sprite can be any pixel width and height, limited only by available RAM. The RAM needed for a 16 bit colour depth Sprite is (2 x width x height) bytes, for a Sprite with 8 bit colour depth the RAM needed is (width x height) bytes. Sprites can be created and deleted dynamically as needed in the sketch, this means RAM can be freed up after the Sprite has been plotted on the screen, more RAM intensive WiFi based code can then be run and normal graphics operations still work.

If an ESP32 board has SPIRAM (i.e. PSRAM) fitted then Sprites will use the PSRAM memory and large full screen buffer Sprites can be created. Full screen Sprites take longer to render (~45ms for a 320 x 240 16 bit Sprite), so bear that in mind.

The "Animated_dial" example shows how dials can be created using a rotated Sprite for the needle. To run this example the TFT interface must support reading from the screen RAM (not all do). The dial rim and scale is a jpeg image, created using a paint program.

The XPT2046 touch screen controller is supported for SPI based displays only. The SPI bus for the touch controller is shared with the TFT and only an additional chip select line is needed. This support will eventually be deprecated when a suitable touch screen library is available.

The library supports SPI overlap on the ESP8266 so the TFT screen can share MOSI, MISO and SCLK pins with the program FLASH, this frees up GPIO pins for other uses. Only one SPI device can be connected to the FLASH pins and the chips select for the TFT must be on pin D3 (GPIO0).

The library contains proportional fonts, different sizes can be enabled/disabled at compile time to optimise the use of FLASH memory. Anti-aliased (smooth) font files in vlw format stored in SPIFFS are supported. Any 16 bit Unicode character can be included and rendered, this means many language specific characters can be rendered to the screen.

Anti-aliased fonts can also be drawn over a gradient background with a callback to fetch the background colour of each pixel. This pixel colour can be set by the gradient algorithm or by reading back the TFT screen memory (if reading the display is supported).

Unfortunately the typical UNO/mcufriend TFT display board maps LCD_RD, LCD_CS and LCD_RST signals to the ESP32 analogue pins 35, 34 and 36 which are input only. To solve this I linked in the 3 spare pins IO15, IO33 and IO32 by adding wires to the bottom of the board as follows:

If the display board is fitted with a resistance based touch screen then this can be used by performing the modifications described here and the fork of the Adafruit library:

The library was intended to support only TFT displays but using a Sprite as a 1 bit per pixel screen buffer permits support for the Waveshare 2 and 3 colour SPI ePaper displays. This addition to the library is experimental and only one example is provided. Further examples will be added.

Besides obvious features like a touchscreen and biometric sensors, the modern smartphone comes with an array of state-of-the-art hardware in the form of various sensors that help your device sense the environment around it. And if you have a Samsung handset, chances are, you have a handy feature built in that enables you to check if these sensors are functioning 100 percent.

Below are the following tests you can perform on your Samsung handset once you"ve input the code and entered HwModuleTest mode. Please note that some may be missing screenshots due to security reasons or the nature of the tests.

To check if your phone"s receiver is working properly, tap on the "Receiver" button to commence testing. Doing so should take you to a white screen, accompanied by a clearly audible dial tone. Once you"re satisfied, simply tap on the back button twice to go back to the main test page.

"Vibration" tests out your phone"s vibration motor. Your screen will go black once you tap on the "Vibration" button, accompanied by a constant vibration. Tap on the screen once to exit this test and go back to the main test screen.

The LED test checks for the functionality of your device"s LED notification light. Running the test is straightforward — simply tap on the "LED" button, then tap on the screen to change the LED"s color from red, to green, and finally to blue. Tap on the screen one last time to end the test and go back to the main diagnostics page.

The Hall IC sensor detects magnetic fields and is primarily used to detect magnetic flip covers to automatically put the phone to sleep when a magnet within the flip cover touches the phone. The test itself doesn"t do much and simply gives a confirmation that the Hall IC functions properly.