M5Dial v1.1 knob/encoder not functional in BSP (BSP-706)

[mfarver]

Board

M5Dial

Hardware Description

M5 Dial version 1.1 (new from manufacturer according to Mouser)

IDE Name

VSCode

Operating System

Windows 10

Description

The knob does not appear to work in the latest version (1.1) of the hardware.

Rotating the knob produces this error in the log but no events into lvgl:

E (87857) lcd_panel.io.i2c: panel_io_i2c_rx_buffer(140): i2c transaction failed
E (87857) FT5x06: esp_lcd_touch_ft5x06_read_data(179): I2C read error!

There is also this warning during initialization:
W (284) i2c: This driver is an old driver, please migrate your application code to adapt "driver/i2c_master.h"

Sketch

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "sdkconfig.h"
#include "bsp/m5dial.h"
#include "lvgl.h"

static void my_event_cb(lv_event_t * event)
{
    printf("Rotated\n");
}

void app_main(void)
{
    /* Initialize display and LVGL */
    display = bsp_display_start();

    lv_display_add_event_cb(display, my_event_cb, LV_EVENT_ROTARY, NULL);   

    for ( ;; )
    {
        vTaskDelay(pdMS_TO_TICKS(500));
    }
}

Other Steps to Reproduce

It may be this is broken on 1.0 hardware as well, I do not have it to test with.

I have checked existing issues, README.md and ESP32 Forum

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[github-actions]

Hi @mfarver! Please be aware that (1) the following suggestions are generated by a bot and haven't been fact-checked by Espressif Systems, (2) burning eFuses and enabling security features are irreversible operations and can damage your ESP32 device. We hope that this message will help you until an Espressif Engineer looks at your issue.

---

Thank you for your detailed report. Based on the information from the Espressif BSP and component documentation, here are some key points and suggestions:

1. Knob/Encoder Support in BSP

The M5Dial BSP officially supports the rotary encoder (knob) via the espressif/knob component, and this is listed as a supported capability for the board in both the main and noglib BSP variants. The knob is a core feature of the M5Dial and should be functional in the BSP for ESP32-S3 targets, including hardware v1.1 Component: m5dial Capabilities.

2. Error Analysis

The error messages you are seeing:

E (87857) lcd_panel.io.i2c: panel_io_i2c_rx_buffer(140): i2c transaction failed
E (87857) FT5x06: esp_lcd_touch_ft5x06_read_data(179): I2C read error!

are related to the FT5x06 touch controller, not the rotary encoder. The FT5x06 is used for the touchscreen, and its I2C communication appears to be failing. This could be due to a hardware connection issue, incorrect I2C pin configuration, or a compatibility issue with the new hardware revision.

The warning:

W (284) i2c: This driver is an old driver, please migrate your application code to adapt "driver/i2c_master.h"

indicates that the I2C driver in use is deprecated, and migration to the newer driver API is recommended. However, this should not directly affect the knob/encoder, unless the knob is also using I2C (which is not indicated in the BSP documentation).

3. Knob/Encoder Events

Your code is registering for LV_EVENT_ROTARY events, which are generated by LVGL when the rotary encoder is integrated with LVGL input devices. However, the BSP and its dependencies (such as the espressif/knob) do not mention direct LVGL integration for the knob. You may need to ensure that the knob is initialized and its events are properly forwarded to LVGL.

4. Recommendations

• Check I2C Pin Configuration: The FT5x06 touch controller uses I2C on GPIO11 (SDA) and GPIO12 (SCL) for the M5Dial API Reference. Ensure these pins are correctly connected and not shared/conflicted with other peripherals.
• Update BSP and Components: Make sure you are using the latest versions of the BSP and all dependencies, as there may be fixes for hardware v1.1.
• Test Knob Independently: Try using the knob without initializing the display or touch to see if it works in isolation. This can help determine if the issue is with the knob itself or an I2C bus conflict.
• Check for Hardware Changes: Since you are using hardware v1.1, verify if there are any changes in the schematic or pinout compared to previous versions. The BSP may need updates if the hardware revision changed the knob's connection or controller.
• Review Example Code: The BSP documentation and component registry do not provide a direct example for LVGL rotary integration. You may need to manually connect the knob events to LVGL if not already handled by the BSP.

5. Next Steps

If the knob is still not functional after these checks, please provide:

• Confirmation of the I2C pin connections for the touch controller.
• Any logs or output when using the knob independently.
• Information on whether the knob is detected at all (e.g., using the espressif/knob component directly).

Summary:
The errors you are seeing are related to the FT5x06 touch controller's I2C communication, not the rotary encoder. The knob should be supported by the BSP, but you may need to ensure it is properly initialized and integrated with LVGL. Double-check hardware connections, update your BSP and components, and test the knob independently to isolate the issue. If the problem persists, it may be due to a hardware revision change that requires BSP updates Capabilities and dependencies.

---

If you need further assistance, please provide additional details as requested above.

[mfarver]

Comparing the two schematics I do not see any differences between them that would explain why the knob is not functioning, or why the error message related to the touch controller occurs when the knob is rotated, despite them not being related.

https://docs.m5stack.com/en/core/M5Dial
https://docs.m5stack.com/en/core/M5Dial%20V1.1

I disabled the touch driver in the BSP by commenting it out:

lv_display_t *bsp_display_start_with_config(const bsp_display_cfg_t *cfg)
{
    assert(cfg != NULL);
    BSP_ERROR_CHECK_RETURN_NULL(lvgl_port_init(&cfg->lvgl_port_cfg));

    BSP_ERROR_CHECK_RETURN_NULL(bsp_display_brightness_init());

    BSP_NULL_CHECK(disp = bsp_display_lcd_init(cfg), NULL);

    //BSP_NULL_CHECK(disp_indev_touch = bsp_display_indev_touch_init(disp), NULL);
    BSP_NULL_CHECK(disp_indev_enc = bsp_display_indev_encoder_init(disp), NULL);

    return disp;
}

This eliminated the error messages from the touch controller, but did not make the knob functional.

Dropping some printfs in the code I can see callbacks from the knob to esp_lvgl_port_knob.c, so the knob itself appears to be working correctly, but there is some problem in lvgl. lvgl is reading the knob differences through lvgl_port_encoder_read.

At this point I'm wondering if the encoder is an event that cannot be read from a display?

[mfarver]

It is looking like that is the case, rotate left right are events that cannot be obtained from a display.

[espzav]

Hi, usage of the `` event is in LVGL documentation:

A "Crown" is a rotary device typically found on smart watches.

When the user clicks somewhere and after that turns the rotary the last clicked widget will be either scrolled or it's value will be incremented/decremented (e.g. in case of a slider).

As this behavior is tightly related to the last clicked widget, the crown support is an extension of the pointer input device. Just set data->diff to the number of turned steps and LVGL will automatically send the LV_EVENT_ROTARY event or scroll the widget based on the editable flag in the widget's class. Non-editable widgets are scrolled and for editable widgets the event is sent.