【GD32450I-EVAL】Transplant touch to LittleVGL

tinnu

【GD32450I-EVAL】Transplant touch to LittleVGL [Copy link]

The previous post tested the touch driver: SPI transceiver and touch chip XPT2046 driver and pen interrupt

The next step is to port to LittleVGL.

Last time when I ported LittleVGL's display, I left behind this:

static bool DEMO_ReadTouch(lv_indev_drv_t * indev_drv, lv_indev_data_t *data)

There is no operation in this function. At this time, you just need to add the touch position and click it.

static bool DEMO_ReadTouch(lv_indev_drv_t * indev_drv, lv_indev_data_t *data)
{
    static int touch_x = 0;
    static int touch_y = 0;
    uint16_t t_xx = 0, t_yy = 0;

    data->state = LV_INDEV_STATE_REL;


    if(gpio_input_bit_get(GPIOI, GPIO_PIN_3)==RESET)
    {
        ReadTPXYOver(&t_xx, &t_yy);
		t_yy = 4096-t_yy;
        touch_x = 480 * t_xx / 4096;
        touch_y = 272 * t_yy / 4096;
        touch_x -= 20;
        touch_y -= 30;
        if (touch_x<0 || touch_x > LCD_WIDTH){
			touch_x =0;
			touch_y =0;
		}
        else if (touch_y<0 || touch_y > LCD_HEIGHT){
			touch_x =0;
			touch_y =0;
		}
		else
			data->state = LV_INDEV_STATE_PR;
    }

    /*Set the last pressed coordinates*/
    data->point.x = touch_x;
    data->point.y = touch_y;

    /*Return `false` because we are not buffering and no more data to read*/
    return false;
}

Due to RAM capacity, only 270*180 width display can be supported, so the actual touch point and the position in LittleVGL must be converted, so the program adds:

        touch_x -= 20;
        touch_y -= 30;

When X is displayed, it is offset to the left by 20 pixels, and Y is offset by 30 pixels. For details, see the transplantation of the display part .

The ReadTPXYOver function performs multiple reads and takes the median after bubble sorting:

void ReadTPXY(uint16_t *t_x, uint16_t *t_y)
{
    char t_char[30] = "";
    gpio_bit_reset(GPIOF, GPIO_PIN_6);
    //X
    while (RESET == spi_i2s_flag_get(SPI3, SPI_FLAG_TBE));
    spi_i2s_data_transmit(SPI4, 0xD0);
    while (RESET == spi_i2s_flag_get(SPI4, SPI_FLAG_RBNE));
    spi_i2s_data_receive(SPI4);

	// delay_us(100);
    //read 1
    while (RESET == spi_i2s_flag_get(SPI3, SPI_FLAG_TBE));
    spi_i2s_data_transmit(SPI4, 0x00);
    while (RESET == spi_i2s_flag_get(SPI4, SPI_FLAG_RBNE));
    *t_x = spi_i2s_data_receive(SPI4);
    *t_x = (*t_x& 0x7F)<<8 ;
    //read2
    while (RESET == spi_i2s_flag_get(SPI3, SPI_FLAG_TBE));
    spi_i2s_data_transmit(SPI4, 0x90);
    while (RESET == spi_i2s_flag_get(SPI4, SPI_FLAG_RBNE));
    *t_x = *t_x|spi_i2s_data_receive(SPI4);

    // sprintf(t_char, "x:%x\t", *t_x);
    // PRINTF_UART0(t_char);

    *t_x = *t_x>>3;

	// delay_us(100);
    
    while (RESET == spi_i2s_flag_get(SPI3, SPI_FLAG_TBE));
    spi_i2s_data_transmit(SPI4, 0x00);
    while (RESET == spi_i2s_flag_get(SPI4, SPI_FLAG_RBNE));
    *t_y = spi_i2s_data_receive(SPI4);
    *t_y = (*t_y& 0x7F) <<8;

    while (RESET == spi_i2s_flag_get(SPI3, SPI_FLAG_TBE));
    spi_i2s_data_transmit(SPI4, 0x00);
    while (RESET == spi_i2s_flag_get(SPI4, SPI_FLAG_RBNE));
    *t_y = *t_y|spi_i2s_data_receive(SPI4);

    // sprintf(t_char, "y:%x\t", *t_y);
    // PRINTF_UART0(t_char);

    *t_y = *t_y>>3;
}

void ReadTPXYOver(uint16_t *t_x, uint16_t *t_y)

Effect:

okhxyyo

GigaDevice GD32450I-EVAL

Summary post: https://bbs.eeworld.com.cn/thread-1140981-1-1.html

freebsder

This is good, awesome!