---

#include <zephyr/kernel.h>
#include <zephyr/drivers/gpio.h>

#define MSG_SIZE 16
#define QUEUE_MAX_MSGS 10
#define LCD_THREAD_STACK 1024

#define LCD_THREAD_PRIORITY 13

#ifdef MY_CODE
/* Get PCF8574 from dts */
static const struct device *pcf_dev = DEVICE_DT_GET(DT_NODELABEL(pcf8574));
#endif

#define LCD_RS        (1 << 0) // Port 0
#define LCD_RW        (1 << 1) // Port 1
#define LCD_E         (1 << 2) // Port 2
#define LCD_BL        (1 << 3) // Port 3 (Backlight)
#define LCD_DATA_MASK 0xF0     // Port 4-7 (D4-D7)

#define LCD_GPIO_PORT_RAW

/* Global var for lcd backlight */
static uint8_t backlight_state = LCD_BL;

//LCD Message 
struct lcd_msg_t {
    char text[MSG_SIZE];
    uint8_t row;
    uint8_t col;
    uint8_t mode;
    uint8_t text_size;
};
K_MSGQ_DEFINE(lcd_msgq, sizeof(struct lcd_msg_t), QUEUE_MAX_MSGS, 4);


//#define USE_GUARD
#ifdef USE_GUARD
#define GUARD_SIZE 2048
static uint8_t lcd_guard_area[GUARD_SIZE] __aligned(4) __attribute__((section(".noinit")));

void check_guard_corruption(void)
{
    int first_corrupted_byte = -1;
    int corrupted_count = 0;

    printf("check guard corruption\n");
    for (int i = 0; i < GUARD_SIZE; i++) {
        if (lcd_guard_area[i] != 0xEE) {
            if (first_corrupted_byte == -1) {
                first_corrupted_byte = i;
            }
            corrupted_count++;
        }
    }

    if (first_corrupted_byte != -1) {
        printf("!!! DETECTED CORRUPTION !!!\n");
        printf("First corrupted byte at offset: %d\n", first_corrupted_byte);
        printf("Total corrupted bytes: %d\n", corrupted_count);
        // Выведем кусок данных для опознания (может там текст или ключи)
        for (int i = 0; i < 100; i += 4) {
        printf("Data: %02x %02x %02x %02x\n", 
               lcd_guard_area[first_corrupted_byte + i], 
               lcd_guard_area[first_corrupted_byte+i + 1],
               lcd_guard_area[first_corrupted_byte+i +2],
               lcd_guard_area[first_corrupted_byte+i +3]);
        }
    }
}

void init_guard(void) {
    memset(lcd_guard_area, 0xEE, GUARD_SIZE);
}
#endif

/* Send 4 bit data*/
void lcd_send_nibble(uint8_t nibble, uint8_t rs_flag)
{
#ifdef MY_CODE
    // Set byte: 4 bits - data, 4 bits- backlight and control
    uint8_t port_val = (nibble << 4) | rs_flag | backlight_state;
    
    // RW always 0 (write mode)
    port_val &= ~LCD_RW; 

    //k_sched_lock();
    // 1. Set data and RS, E -> 0
#ifdef LCD_GPIO_PORT_RAW
    gpio_port_set_masked_raw(pcf_dev, 0xFF, port_val);
#else
    gpio_port_set_bits_raw(pcf_dev, port_val);
    gpio_port_clear_bits_raw(pcf_dev, ~port_val & 0xFF);
#endif
    k_busy_wait(1);

    // 2. Enable (E = 1) for set data on display
#ifdef LCD_GPIO_PORT_RAW
    gpio_port_set_masked_raw(pcf_dev, 0xFF, port_val | LCD_E);
#else
    gpio_port_set_bits_raw(pcf_dev, LCD_E);
#endif
    k_busy_wait(1);

    // 3. Reset Enable (E = 0)
#ifdef LCD_GPIO_PORT_RAW
    gpio_port_set_masked_raw(pcf_dev, 0xFF, port_val);
#else
    gpio_port_clear_bits_raw(pcf_dev, LCD_E);
#endif
    //k_sched_unlock();
    k_busy_wait(5);
#endif
}

/* Send 8 bit function */
void lcd_send_byte(uint8_t value, uint8_t rs_flag)
{
    lcd_send_nibble(value >> 4, rs_flag);
    lcd_send_nibble(value & 0x0F, rs_flag);
}

void lcd_command(uint8_t cmd)  { lcd_send_byte(cmd, 0); }
void lcd_data(uint8_t data)   { lcd_send_byte(data, LCD_RS); }

/* Init display 1602A in 4-bit mode */
int lcd_init(void)
{
    int i,ret;

#ifdef MY_CODE
#ifdef USE_GUARD
    init_guard();
#endif
    if(!device_is_ready(pcf_dev)) {
        printf("Error: No i2c PCF device\n");
        return -ENODEV;
    }
    for(i=0; i < 8; i++)
    {
        ret = gpio_pin_configure(pcf_dev, i, GPIO_OUTPUT_INACTIVE);
        if(ret < 0)
        {
            printf("Error gpio_pin_configure %d err=%d\n",i,ret);
            //return ret;
        }
    }
    k_msleep(50);
    // Set controller HD44780 to 4-bit mode
    lcd_send_nibble(0x03, 0);
    k_msleep(5);
    lcd_send_nibble(0x03, 0);
    k_busy_wait(150);
    lcd_send_nibble(0x03, 0);
    k_busy_wait(150);
    lcd_send_nibble(0x02, 0);
    k_msleep(2);

    // Set display parameters
    lcd_command(0x28); // 4-bit mode, 2 lines, font 5x8
    lcd_command(0x0C); // Display ON, Cursor OFF, Blinking OFF
    lcd_command(0x06); // Autoincrement cursor
    lcd_command(0x01); // Clean display
    k_msleep(2);
#endif
    return 1;
}

/* Set cursor position */
void lcd_set_cursor(uint8_t col, uint8_t row)
{
    uint8_t row_offsets[2] = {0x00, 0x40};
    lcd_command(0x80 | (col + row_offsets[row]));
}

/* Print line */
void lcd_print(const char *str, uint8_t len)
{
    while (len && *str) {
        lcd_data(*str++);
        len--;
    }
}

//mode = 0 - clear 16 symbols, add data
//mode = 1 - only clear 16 symbols
//mode = 2 - append mode data without clear
void lcd_render_thread(void *p1, void *p2, void *p3)
{
    struct lcd_msg_t msg;
    uint8_t i = 0;

    while (1) {
        // Wait message queue
        if (k_msgq_get(&lcd_msgq, &msg, K_FOREVER) == 0)
        {
            if(msg.mode != 2) //not append mode
            {
                lcd_set_cursor(msg.col, msg.row);
                for(i=0; i < 16 - msg.col; i++)
                    lcd_data(' ');
            }
            if(msg.mode != 1)
            {
                lcd_set_cursor(msg.col, msg.row);
                lcd_print(msg.text, msg.text_size);
            }
            k_msleep(1);
        }
    }
}

K_THREAD_DEFINE(lcd_thread_id, LCD_THREAD_STACK, lcd_render_thread, NULL, NULL, NULL, LCD_THREAD_PRIORITY, 0, 0);

int safe_lcd_print(uint8_t col, uint8_t row, const char *text, uint8_t mode)
{
    struct lcd_msg_t msg;
    size_t len = MSG_SIZE;

#ifdef USE_GUARD
    check_guard_corruption();
#endif
    len = strlen(text);
    if(text == NULL || len <= 0)
        return 0;
    if(col >= 16)
        col = 15;
    if(row > 1)
        row = 1;
    msg.col = col;
    msg.row = row;
    msg.mode = mode;
    if(len >= MSG_SIZE)
        len = MSG_SIZE - 1;
    msg.text_size = len;
    strncpy(msg.text, text, len);
    msg.text[len] = '\0';
    // Set to queue, if queue is full - don't wait (K_NO_WAIT)
    return k_msgq_put(&lcd_msgq, &msg, K_NO_WAIT);
}

Проект pjsip imxrt1024. Надо убрать PCF8574 и заменить код на прямое подключение:
LED_BACKLIGHT_EN = GPIO_AD_B1_08
LED_RW = GPIO_AD_B1_07
LED_RS = GPIO_AD_B1_13
LED_E = GPIO_AD_B1_10
LED_D4 = GPIO_AD_B1_09
LED_D5 = GPIO_SD_B1_00
LED_D6 = GPIO_SD_B1_01
LED_D7 = GPIO_SD_B1_10