ESP32-WROVER-KIT-LCD-DRIVER
Functions | Variables
Driver.c File Reference

write the Framebuffer More...

#include "Driver.h"
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Functions

uint32_t vDriver_GetId (void)
 get LCD driver chip id More...
 
static esp_err_t iDriver_sendLineFinish (void)
 send finish after line More...
 
void vDriver_spiPreTransferCallback (spi_transaction_t *t)
 Pre Transfer Callback. More...
 
esp_err_t iDriver_sendCmd (const uint8_t u8Cmd)
 Send a command to the LCD. More...
 
static esp_err_t iDriver_sendLines (uint16_t u16Ypos, uint16_t *pu16Linedata)
 send line to lcd chip More...
 
esp_err_t iDriver_SendData (const uint8_t *pu8Data, uint16_t u16Len)
 Send data to the LCD. More...
 
void vDriver_getFramenufferPerLine (uint16_t *pu16Dest, uint16_t u16Line, uint16_t u16Linect, uint16_t ***pu16Framebuffer)
 Get the pixel data for a set of lines (with implied line size of 320) More...
 
esp_err_t vDriver_init (void)
 Initialize the driver. More...
 
esp_err_t iDriver_writeFramebuffer (uint16_t ***pu16Framebuffer)
 write framebuffer to LCD via SPI More...
 

Variables

spi_device_handle_t spi
 
uint16_t * lines [2]
 
int16_t sending_line =-1
 
int16_t calc_line =0
 
static DRAM_ATTR const lcd_init_cmd_t st_init_cmds []
 
static DRAM_ATTR const lcd_init_cmd_t ili_init_cmds []
 

Detailed Description

write the Framebuffer

Author
Hendrik Schutter
Version
V1.0
Date
03.11.2020

This code used SPI to write data to the LCD driver like ILI9341 or ST7789V.

Function Documentation

◆ iDriver_sendCmd()

esp_err_t iDriver_sendCmd ( const uint8_t  u8Cmd)

Send a command to the LCD.

Parameters
constuint8_t u8Cmd
Returns
esp error code
Author
Hendrik Schutter
Date
3.11.2020

Send a command to the LCD. Uses spi_device_polling_transmit, which waits until the transfer is complete.

Since command transactions are usually small, they are handled in polling mode for higher speed. The overhead of interrupt transactions is more than just waiting for the transaction to complete.

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◆ iDriver_SendData()

esp_err_t iDriver_SendData ( const uint8_t *  pu8Data,
uint16_t  u16Len 
)

Send data to the LCD.

Parameters
constuint8_t *pu8Data
uint16_tu16Len
Returns
esp error code
Author
Hendrik Schutter
Date
3.11.2020

Send data to the LCD. Uses spi_device_polling_transmit, which waits until the transfer is complete.

Since data transactions are usually small, they are handled in polling mode for higher speed. The overhead of interrupt transactions is more than just waiting for the transaction to complete.

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◆ iDriver_sendLineFinish()

static esp_err_t iDriver_sendLineFinish ( void  )
static

send finish after line

Parameters
void
Returns
esp error code
Author
Hendrik Schutter
Date
3.11.2020
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◆ iDriver_sendLines()

static esp_err_t iDriver_sendLines ( uint16_t  u16Ypos,
uint16_t *  pu16Linedata 
)
static

send line to lcd chip

Parameters
uint16_tu16Ypos
uint16_t*pu16Linedata
Returns
esp error code
Author
Hendrik Schutter
Date
3.11.2020

To send a set of lines we have to send a command, 2 data bytes, another command, 2 more data bytes and another command before sending the line data itself; a total of 6 transactions. (We can't put all of this in just one transaction because the D/C line needs to be toggled in the middle.) This routine queues these commands up as interrupt transactions so they get sent faster (compared to calling spi_device_transmit several times), and at the mean while the lines for next transactions can get calculated.

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◆ iDriver_writeFramebuffer()

esp_err_t iDriver_writeFramebuffer ( uint16_t ***  pu16Framebuffer)

write framebuffer to LCD via SPI

Parameters
uint16_t***pu16Framebuffer
Returns
esp error code
Author
Hendrik Schutter
Date
3.11.2020
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◆ vDriver_getFramenufferPerLine()

void vDriver_getFramenufferPerLine ( uint16_t *  pu16Dest,
uint16_t  u16Line,
uint16_t  u16Linect,
uint16_t ***  pu16Framebuffer 
)

Get the pixel data for a set of lines (with implied line size of 320)

Parameters
uint16_t*pu16Dest
uint16_tu16Line
uint16_tu16Linect
uint16_t***pu16Framebuffer
Returns
void
Author
Hendrik Schutter
Date
3.11.2020
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◆ vDriver_GetId()

uint32_t vDriver_GetId ( void  )

get LCD driver chip id

Parameters
void
Returns
uint32_t
Author
Hendrik Schutter
Date
3.11.2020
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◆ vDriver_init()

esp_err_t vDriver_init ( void  )

Initialize the driver.

Parameters
void
Returns
esp error code
Author
Hendrik Schutter
Date
3.11.2020

Enable backlight

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◆ vDriver_spiPreTransferCallback()

void vDriver_spiPreTransferCallback ( spi_transaction_t *  t)

Pre Transfer Callback.

Parameters
spi_transaction_t*t
Returns
void
Author
Hendrik Schutter
Date
3.11.2020

This function is called (in irq context!) just before a transmission starts. It will set the D/C line to the value indicated in the user field.

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Variable Documentation

◆ calc_line

int16_t calc_line =0

◆ ili_init_cmds

DRAM_ATTR const lcd_init_cmd_t ili_init_cmds[]
static

◆ lines

uint16_t* lines[2]

◆ sending_line

int16_t sending_line =-1

◆ spi

spi_device_handle_t spi

◆ st_init_cmds

DRAM_ATTR const lcd_init_cmd_t st_init_cmds[]
static