lcd panel bpp free sample

BPP-420 understands traditional control codes, such as Tab LF/CR FF/Clear Backspace etc. Additional features are mapped to other control codes or Escape sequences. A quick summary:

The best solution I can think of is based on a random dithering that changes every frame. This combines the advantage of dithering with not having a fixed dithering pattern, and since a given pixel changes values many times a second what you perceive is closer to the average of those various values, which is closer to the original "deep color" value than any given 24 bpp value.

sfb being the sRGB 24 bpp buffer, fb being the 45 bpp linear RGB buffer, lsrgb_l.lutint[] being the linear to gamma-compressed LUT, dither_l.lutint[] the LUT containing the random Gaussian numbers in 2.5 fixed point format and bytecheck_l.lutb[] returning values clipped to [0 , 255].

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 _.

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_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).

Most operating systems have the option to change the screen resolution, which is useful in certain situations, such as plugging a laptop into an external display that has a different function than the built-in display. The optimal resolution of a computer monitor usually depends on the physical size of the display (especially an LCD or LED screen).

640 × 480 pixels indirect 16 bits-per-pixel (65,536 colors) RGB hi-color (XGA only, with 1 MB video memory option) and 8 bpp (256 colors) palette-indexed mode.

1024 × 768 pixels with a 16- or 256-color (4 or 8 bpp) palette, using a low frequency interlaced refresh rate (again, the higher 8 bpp mode required 1 MB VRAM.

BPP-440 understands traditional control codes, such as Tab LF/CR FF/Clear Backspace etc. Additional features are mapped to other control codes or Escape sequences. A quick summary:

Version 2.0 introduces new generalized information blocks primarily intended for UltraHD High Dynamic Range (HDR) displays, such as LCD computer monitors and LCD/OLED televisions with native support for BT.2100 color space and PQ/HLG transfer functions. It also makes optional predefined CRT/LCD timings from DMT and CEA-861 standards, switching to formula-based structures which follow VESA CVT-RB and GTF.

0x28 Tiled display topology block describes displays that consist of multiple physical display panels, each driven by a separate video interface. It is based on block 0x12.

0x0C Display device data block provides information about display panel characteristics for embedded applications, such as display technology, panel type, and pixel response times.

A common size for LCDs manufactured for small consumer electronics, basic mobile phones and feature phones, typically in a 1.7" to 1.9" diagonal size. This LCD is often used in portrait (128×160) orientation. The unusual 5:4 aspect ratio makes the display slightly different from QQVGA dimensions.

A shared size for older portable video game systems. The nearly-square (but landscape) aspect ratio and coarse pixel resolution gave these games a characteristic visual style. Colour depth ranged from 4 colours (2 bpp) with the original Game Boy, through 16–32 colours (4–5 bpp) with the Atari Lynx and Game Gear, to a maximum of 56 colours (equivalent of 6 bpp) from a wider palette with the Game Boy Color. Also appears as a YouTube resolution option ("144p").

Used with some smaller, cheaper portable devices, including lower-end cellphones and PDAs, and perhaps most commonly in the Nintendo Game Boy Advance (with, in that guise, 32k colours (15 bpp) on-screen).

Half the resolution in each dimension as standard VGA. First appeared as a VESA mode (134h=256 color, 135h=Hi-Color) that primarily allowed 80x30 character text with graphics, and should not be confused with CGA (320x200); QVGA is normally used when describing screens on portable devices (PDAs, pocket media players, feature phones, smartphones, etc.). No set colour depth or refresh rate is associated with this standard or those that follow, as it is dependent both on the manufacturing quality of the screen and the capabilities of the attached display driver hardware, and almost always incorporates an LCD panel with no visible line-scanning. However, it would typically be in the 8-to-12 bpp (256–4096 colours) through 18 bpp (262,144 colours) range.

Up to 6 bpp for Amiga (8 bpp with later models), typically 2–4 bpp for most hi-res applications (saving memory and processing time), 4–5 bpp for games and "fake" 12/18 bpp for static images (HAM mode). Up to 15 bpp for Archimedes and Falcon (12 bpp for TT), but typically 4 bpp in use.

Later, larger monitors (15" and 16") allowed use of an SVGA-like binary-half-megapixel 832×624 resolution (at 75 Hz) that was eventually used as the default setting for the original, late-1990s iMac. Even larger 17" and 19" monitors could attain higher resolutions still, when connected to a suitably capable computer, but apart from the 1152×870 "XGA+" mode discussed further below, Mac resolutions beyond 832×624 tended to fall into line with PC standards, using what were essentially rebadged PC monitors with a different cable connection. Mac models after the II (Power Mac, Quadra, etc.) also allowed at first 16-bit High Colour (65,536, or "Thousands of" colours), and then 24-bit True Colour (16.7M, or "Millions of" colours), but much like PC standards beyond XGA, the increase in colour depth past 8 bpp was not strictly tied to changing resolution standards.

The first PowerBook, released in 1991, replaced the original Mac Portable (basically an original Mac with an LCD, keyboard and trackball in a lunchbox-style shell), and introduced a new 640×400 greyscale screen. This was joined in 1993 with the PowerBook 165c, which kept the same resolution but added colour capability similar to that of Mac II (256 colours from a palette of 16.7 million).

Introduced in 1984 by IBM. A resolution of 640×350 pixels of 16 different colours in 4 bits per pixel (bpp), selectable from a 64-colour palette in 2 bits per each of red-green-blue (RGB) unit.DIP switch options; plus full EGA resolution (and CGA hi-res) in monochrome, if installed memory was insufficient for full colour at above 320×200.

Introduced on MCA-based PS/2 models in 1987, it replaced the digital TTL signaling of EGA and earlier standards with analog RGBHV signaling, using the synonymous VGA connector. As with EGA, the VGA standard actually encompasses a set of different resolutions; 640×480 is sometimes referred to as "VGA resolution" today, however as per the original standard this mode actually only supports 16 colours (4 bpp) at 60 Hz. Other common display modes also defined as VGA include 320×200 at 256 colours (8 bpp) (standard VGA resolution for DOS games that stems from halving the pixel rate of 640×400, but doubling color depth) and a text mode with 720×400 pixels; these modes run at 70 Hz and use non-square pixels, so 4:3 aspect correction is required for correct display.

Furthermore, VGA displays and adapters are generally capable of Mode X graphics, an undocumented mode to allow increased non-standard resolutions, most commonly 320×240 (with 8 bpp and square pixels) at 60 Hz.

The high-resolution mode introduced by 8514/A became a de facto general standard in a succession of computing and digital-media fields for more than two decades, arguably more so than SVGA, with successive IBM and clone videocards and CRT monitors (a multisync monitor"s grade being broadly determinable by whether it could display 1024×768 at all, or show it interlaced, non-interlaced, or "flicker-free"), LCD panels (the standard resolution for 14" and 15" 4:3 desktop monitors, and a whole generation of 11–15" laptops), early plasma and HD ready LCD televisions (albeit at a stretched 16:9 aspect ratio, showing down-scaled material), professional video projectors, and most recently, tablet computers.

Over the course of the early-to-mid-1990s, "SVGA" became a quasi-standard term in PC games, typically referring to a 640×480 resolution using 256 colours (8 bpp) at 60 Hz refresh rate. Many other higher and lower modes were standardized in the VESA BIOS Extensions, leading to the establishment of "SVGA" and "VESA" as catch-all terms encompassing output modes that surpassed the original VGA specifications.

An IBM display standard introduced in 1990. XGA built on 8514/A"s existing 1024×768 mode and added support for "high colour" (65,536 colours, 16 bpp) at 640×480. The second revision ("XGA-2") was a more thorough upgrade, offering higher refresh rates (75 Hz and up, non-interlaced, up to at least 1024×768), improved performance, and a fully programmable display engine capable of almost any resolution within its physical limits. For example, 1280×1024 (5:4) or 1360×1024 (4:3) in 16 colours at 60 Hz, 1056×400 [14h] Text Mode (132×50 characters); 800×600 in 256 or 64k colours; and even as high as 1600×1200 (at a reduced 50 Hz scan rate) with a high-quality multisync monitor (or an otherwise non-standard 960×720 at 60 Hz on a lower-end one capable of high refresh rates at 800×600, but only interlaced mode at 1024×768).I, 640×480×16 NI, high-res text) were commonly used outside Windows and other hardware-abstracting graphical environments.

A widely used aspect ratio of 5:4 (1.25:1) instead of the more common 4:3 (1.33:1), meaning that even 4:3 pictures and video will appear letterboxed on the narrower 5:4 screens. This is generally the native resolution—with, therefore, square pixels—of standard 17" and 19" LCD monitors. It was often a recommended resolution for 17" and 19" CRTs also, though as they were usually produced in a 4:3 aspect ratio, it either gave non-square pixels or required adjustment to show small vertical borders at each side of the image. Allows 24-bit colour in 4 MB of graphics memory, or 4-bit colour in 640 kB.

An enhanced version of the WXGA format. This display aspect ratio was common in widescreen notebook computers, and many 19" widescreen LCD monitors until ca. 2010.

A wide version of the SXGA+ format, the native resolution for many 22" widescreen LCD monitors, also used in larger, wide-screen notebook computers until ca. 2010.

This display aspect ratio is the native resolution for many 24" widescreen LCD monitors, and is expected to also become a standard resolution for smaller-to-medium-sized wide-aspect tablet computers in the near future (as of 2012).

A wide version of the UXGA format. This display aspect ratio was popular on high-end 15" and 17" widescreen notebook computers, as well as on many 23–27" widescreen LCD monitors, until ca. 2010. It is also a popular resolution for home cinema projectors, besides 1080p, in order to show non-widescreen material slightly taller than widescreen (and therefore also slightly wider than it might otherwise be), and is the highest resolution supported by single-link DVI at standard colour depth and scan rate (i.e., no less than 24 bpp and 60 Hz non-interlaced)

A version of the XGA format, the native resolution for many 30" widescreen LCD monitors. Also, the highest resolution supported by dual-link DVI at a standard colour depth and non-interlaced refresh rate (i.e. at least 24 bpp and 60 Hz). Used on MacBook Pro with Retina display (13.3"). Requires 12 MB of memory/bandwidth for a single frame.