Problem when using esp_lcd_panel_init (for ST7701s) with Wi-Fi provisioning using Homekit? (IDFGH-12112)

[puddletowntom]

Answers checklist.

• [X] I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• [X] I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• [X] I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

When i use an LCD display (ST7701s https://github.com/wireless-tag-com/ZX2D10GE01R-V4848) with the Homekit (esp-homekit-sdk), the pairing stops working when using a simple example such as the lightbulb example. Running the Homekit example by itself works fine for Wi-Fi provisioning and pairing. In addition, the display works fine by itself also. But when i try to use the 2 modules at the same time it prevents connection and pairing. It seems like i have narrowed the problem down to esp_lcd_panel_init() because if i remove this, the problem goes away but obviously that is required for using the display. I have tried playing around with the Wi-Fi configurations and the LCD configurations but to no avail. I am starting to assume there is some kind of memory issue where the two modules are interfering with one another with shared resources. I have noticed that there is support in the IDF for the display st7789 (esp_lcd_panel_st7789.c ). I am wondering is the initialisation from the code attached enough to work with Wi-Fi provisioning as the ST7789 seems more developed. Are any of the developers for the IDF aware of issues around LCD panel initialisation conflicting with Wi-Fi provisioning? The LCD is using double frame buffers, it uses octal 8MB of PSRAM. It would be nice if there was added support in the IDF for the ST7701s.

void qmsd_rgb_init(esp_lcd_rgb_panel_config_t *panel_config)
{
    static lv_disp_drv_t disp_drv;
    int buffer_size;
    void *buf1 = NULL;
    void *buf2 = NULL;
    static lv_disp_draw_buf_t draw_buf;

    lv_init();

    ESP_ERROR_CHECK(esp_lcd_new_rgb_panel(panel_config, &g_panel_handle));
    ESP_ERROR_CHECK(esp_lcd_panel_reset(g_panel_handle));
    //ESP_ERROR_CHECK(esp_lcd_panel_init(g_panel_handle));

    // buffer_size = panel_config->timings.h_res * panel_config->timings.v_res;
    // esp_lcd_rgb_panel_get_frame_buffer(g_panel_handle, 2, &buf1, &buf2);
    // lv_disp_draw_buf_init(&draw_buf, buf1, buf2, buffer_size);

    // lv_disp_drv_init(&disp_drv);         
    // disp_drv.flush_cb = __qsmd_rgb_disp_flush;
    // disp_drv.draw_buf = &draw_buf;
    // disp_drv.hor_res = panel_config->timings.h_res;
    // disp_drv.ver_res = panel_config->timings.v_res;
    // lv_disp_drv_register(&disp_drv);
}

The panel configuration from the link looks like this,

esp_lcd_rgb_panel_config_t panel_config = {
        .data_width = 16,
        .psram_trans_align = 64,
        .pclk_gpio_num = LCD_PCLK_GPIO,
        .vsync_gpio_num = LCD_VSYNC_GPIO,
        .hsync_gpio_num = LCD_HSYNC_GPIO,
        .de_gpio_num = LCD_DE_GPIO,
        .disp_gpio_num = LCD_DISP_EN_GPIO,
        .data_gpio_nums = {
            LCD_DATA0_GPIO,
            LCD_DATA1_GPIO,
            LCD_DATA2_GPIO,
            LCD_DATA3_GPIO,
            LCD_DATA4_GPIO,
            LCD_DATA5_GPIO,
            LCD_DATA6_GPIO,
            LCD_DATA7_GPIO,
            LCD_DATA8_GPIO,
            LCD_DATA9_GPIO,
            LCD_DATA10_GPIO,
            LCD_DATA11_GPIO,
            LCD_DATA12_GPIO,
            LCD_DATA13_GPIO,
            LCD_DATA14_GPIO,
            LCD_DATA15_GPIO,
        },
        .timings = {
            .pclk_hz = 15000000,
            .h_res = 480,
            .v_res = 480,
            .hsync_pulse_width = 10,
            .hsync_back_porch = 10,
            .hsync_front_porch = 10, 
            .vsync_pulse_width = 2,
            .vsync_back_porch = 12,
            .vsync_front_porch = 14,
        },
        .flags.fb_in_psram = 1,
        .flags.double_fb = 1,
        .flags.refresh_on_demand = 0,   // Mannually control refresh operation
        .bounce_buffer_size_px = 0,
        .clk_src = LCD_CLK_SRC_PLL160M,
    };

    qmsd_rgb_init(&panel_config);

Using,

ESP-IDF: v5.1.2 LVGL: 8.3.3

[suda-morris]

If PSRAM is used and WiFi memory is prefered to allocate in PSRAM first --- esp_wifi/README.md

Yes, both the wifi and RGB LCD drivers are accessing the PSRAM.

What's the behavior of the LCD when it's doing the wifi connection? Does CONFIG_SPIRAM_FETCH_INSTRUCTIONS=y CONFIG_SPIRAM_RODATA=y help?

BTW, my colleague told me we have a ST7701 driver on the component registry: https://components.espressif.com/components/espressif/esp_lcd_st7701

[Lzw655]

Hi @puddletowntom, according to your test, there might be an issue with memory shortage. Please refer to the following code to periodically print the current remaining space by using a task:

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "esp_heap_caps.h"

    static char buffer[128];    /* Make sure buffer is enough for `sprintf` */
    while (1) {
        sprintf(buffer, "   Biggest /     Free /    Total\n"
                "\t  SRAM : [%8d / %8d / %8d]\n"
                "\t PSRAM : [%8d / %8d / %8d]",
                heap_caps_get_largest_free_block(MALLOC_CAP_INTERNAL),
                heap_caps_get_free_size(MALLOC_CAP_INTERNAL),
                heap_caps_get_total_size(MALLOC_CAP_INTERNAL),
                heap_caps_get_largest_free_block(MALLOC_CAP_SPIRAM),
                heap_caps_get_free_size(MALLOC_CAP_SPIRAM),
                heap_caps_get_total_size(MALLOC_CAP_SPIRAM));
        ESP_LOGI("MEM", "%s", buffer);

        vTaskDelay(pdMS_TO_TICKS(2000));
    }

[puddletowntom]

@suda-morris I didnt realise that there was a more developed ST7701 driver from the components registry as you posted so thank you for pointing that out to me. I went ahead and tried it out instead of the display code I had been using because i wanted to see if there was any improvement in performance. I had to adjust the commands to match my display but got the display going with this esp_lcd_st7701 driver. Unfortunately this didnt change the behaviour of of the Wi-Fi application. CONFIG_SPIRAM_FETCH_INSTRUCTIONS and CONFIG_SPIRAM_RODATA are both enabled but this doesnt change the behaviour of Wi-Fi either.

@Lzw655 I am not sure if there is a memory shortage. Here is the result of the print out. For this i am only initialising the display while running the Wi-Fi application. Just to reiterate, Wi-Fi connects and pairs when removing the display initialisation.

I (10994) app_wifi: Disconnected. Connecting to the AP again...
I (12044) MEM:    Biggest /     Free /    Total
          SRAM : [   31744 /    80355 /   342583]
         PSRAM : [ 6422528 /  6549096 /  7012352]
I (13404) app_wifi: Disconnected. Connecting to the AP again...
I (14044) MEM:    Biggest /     Free /    Total
          SRAM : [   31744 /    80363 /   342583]
         PSRAM : [ 6422528 /  6549096 /  7012352]
I (15814) app_wifi: Disconnected. Connecting to the AP again...
I (16044) MEM:    Biggest /     Free /    Total
          SRAM : [   31744 /    80191 /   342583]
         PSRAM : [ 6422528 /  6549096 /  7012352]
I (18044) MEM:    Biggest /     Free /    Total
          SRAM : [   31744 /    80371 /   342583]
         PSRAM : [ 6422528 /  6549096 /  7012352]

Thank you for the response.

[puddletowntom]

So I think i have found a work around. I havent fully implemented it yet but i noticed from the esp-iot-solutions repo that there is a wifi lvgl example found here, https://github.com/espressif/esp-iot-solution/tree/master/examples/hmi/lvgl_wificonfig

In this example, they seem to protect wifi commands from lvgl with the following,

lvgl_acquire();
start_wifi_scan();
lvgl_release();

lvgl_acquire();
wifi_connect_success();
lvgl_release();

I noticed that i was able to connect to Wi-Fi when I disengage the panel. eg using the following,

void disconnect_panel(void){
    esp_lcd_panel_io_del(io_handle);
    esp_lcd_panel_del(panel_handle);
}

However, I cannot really do this in the middle of a task because i would obviously have to reinitialise the panel for the display. Its a little messy but if i can use the acquire/release system from the example this might work.