Clarification about display initialization messages

[LeCyberDucky]

Hey, I'm wondering if somebody could elaborate on the display initialization seen in https://github.com/Xinyuan-LilyGO/T-Display-S3/blob/main/examples/lv_demos/lv_demos.ino

1. What do these commands mean?

lcd_cmd_t lcd_st7789v[] = {
    {0x11, {0}, 0 | 0x80},
    {0x3A, {0X05}, 1},
    {0xB2, {0X0B, 0X0B, 0X00, 0X33, 0X33}, 5},
    {0xB7, {0X75}, 1},
    {0xBB, {0X28}, 1},
    {0xC0, {0X2C}, 1},
    {0xC2, {0X01}, 1},
    {0xC3, {0X1F}, 1},
    {0xC6, {0X13}, 1},
    {0xD0, {0XA7}, 1},
    {0xD0, {0XA4, 0XA1}, 2},
    {0xD6, {0XA1}, 1},
    {0xE0, {0XF0, 0X05, 0X0A, 0X06, 0X06, 0X03, 0X2B, 0X32, 0X43, 0X36, 0X11, 0X10, 0X2B, 0X32}, 14},
    {0xE1, {0XF0, 0X08, 0X0C, 0X0B, 0X09, 0X24, 0X2B, 0X22, 0X43, 0X38, 0X15, 0X16, 0X2F, 0X37}, 14},
};

2. In the code that transmits the commands:

for (uint8_t i = 0; i < (sizeof(lcd_st7789v) / sizeof(lcd_cmd_t)); i++) {
        esp_lcd_panel_io_tx_param(io_handle, lcd_st7789v[i].cmd, lcd_st7789v[i].data, lcd_st7789v[i].len & 0x7f);
        if (lcd_st7789v[i].len & 0x80)
            delay(120);
    }

Why do we have the bitwise ands with 0x7f and 0x80, and why do we have the 120 second delay?

[lewisxhe]

This part of initialization is provided by the screen manufacturer. If this part of the initialization command is not added, the pixels will be blurred.

[github-actions[bot]]

This issue is stale because it has been open for 30 days with no activity.

[github-actions[bot]]

This issue was closed because it has been inactive for 14 days since being marked as stale.