NET OS%206.1%20Training

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NETOS 6.1 Training
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LCD Driver
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LCD Driver

• LCD Driver API in BSP
• Open Sequence
• Close Sequence
• ioctl Requests
• LCD_PANEL_INFO_TYPE
• FRAME_BUFFER_TYPE
• PALETTE_ENTRY_TYPE

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LCD Driver API

• open() open a display device
• ioctl() set up/change/get display device info
• close() close a display device
• read()not implemented
• write()not implemented

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Open Sequence

• Open the device
• fd open ("/display/0", O_RDWR)
• Set up the LCD display
• retval ioctl (fd, LCD_SET_DISPLAY_TYPE, (void
  )lcdInfo)
• Control enable
• on 1
• retval ioctl (fd, LCD_SET_CONTROL_ENABLE,
  (void )on)
• Delay according to LCD data sheet
• tx_thread_sleep (TFT_DELAY_TIME)
• Power enable
• on 1
• retval ioctl (fd, LCD_SET_POWER_ENABLE, (void
  )on)

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Close Sequence

• Disable LCD power
• on 0
• ioctl (fd, LCD_SET_POWER_ENABLE, (void )on)
• Delay according to LCD data sheet
• tx_thread_sleep (TFT_DELAY_TIME)
• Disable LCD control
• on0
• ioctl (fd, LCD_SET_CONTROL_ENABLE, (void
  )on)
• Close device
• close (fd)

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ioctl Requests

• LCD_SET_DISPLAY_TYPE
• LCD_SET_CONTROL_ENABLE
• LCD_SET_POWER_ENABLE
• LCD_GET_PRIMARY_BUFFER
• LCD_GET_CURRENT_BUFFER
• LCD_SET_SWITCH_BUFFER
• LCD_SET_PALETTE_ENTRY
• LCD_GET_DISPLAY_WIDTH
• LCD_GET_DISPLAY_HEIGHT
• LCD_GET_DISPLAY_BPP
• LCD_GET_DISPLAY_BYTEORDER
• LCD_GET_DISPLAY_PIXELORDER
• LCD_GET_DISPLAY_TYPE
• LCD_GET_PALETTE_SIZE

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LCD_PANEL_INFO_TYPE

• typedef struct
• int lcdType
• int lcdColor
• int lcdMono8
• int lcdWidth
• int lcdHeight
• unsigned char lcdBpp
• unsigned char lcdClockSelect
• int lcdBypassPixelClockDivider
• unsigned char lcdPanelClockDivisor
• int lcdPixelOrder
• int lcdByteOrder
• int lcdRGB
• unsigned char lcdHorzBackPorch
• unsigned char lcdHorzFrontPorch
• unsigned char lcdHorzSyncPulseWidth
• unsigned char lcdVertBackPorch
• unsigned char lcdVertFrontPorch

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FRAME_BUFFER_TYPE

• typedef struct
• char frameBuffer
• int frameBufferLength
• FRAME_BUFFER_TYPE
• frameBuffer cant be in WRITE_BACK cached memory
  region

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PALETTE_ENTRY_TYPE

• typedef struct
• int paletteIndex
• int intensity
• unsigned char red
• unsigned char green
• unsigned char blue
• PALETTE_ENTRY_TYPE

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GUI API

• Separate Library
• Pixel API - put one pixel on the display
• - dcPutPixel()
• Bitmap API - decode and display a bitmap file
• - dcDecodeBitmapHeader()
• - dcDisplayBmp()
• - dcSetUpPaletteFromBitmap

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Double Buffering

• Call dcPutPixel() with an user frame buffer
• Call ioctl with request LCD_SET_SWITCH_BUFFER
• Call dcDisplayBmp() with an user frame buffer
• Call ioctl with request LCD_SET_SWITCH_BUFFER

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For example dcPutPixel()

• int dcPutPixel (
• int fd,
• FRAME_BUFFER_TYPE frameBuffer,
• int x,
• int y,
• unsigned char red,
• unsigned char green,
• unsigned char blue,
• int intensity)

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References

• HW manual
• Auto doc LCD driver and GUI library
• Examples/lcd_tft24
• Data sheets
• - Sharp LQ10D421
• - Sharp LM057QC1T01
• - Grand Pacific Optoelectronics Corp
  GPG240X320-NFPDELW3
• - LG. Philips LCD Co. , Ltd LCD130V01