ESP32C6 incorrect temp_sensor reading after disable and re-enable (IDFGH-11766)

[AxelLin]

Answers checklist.

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

IDF version.

v5.1.2-496-g3629f070b6

Espressif SoC revision.

ESP32C6

Operating System used.

Linux

How did you build your project?

Command line with idf.py

If you are using Windows, please specify command line type.

None

Development Kit.

Custom Board

Power Supply used.

USB

What is the expected behavior?

temperature_sensor_get_celsius() should get correct temperature reading.

What is the actual behavior?

If calling temperature_sensor_disable() and temperature_sensor_enable() again, the reading becomes wrong.

Steps to reproduce.

A modified code of examples/peripherals/temperature_sensor as below shows the symptom.
Only the first reading shows correct tsens_value.
If calling temperature_sensor_disable() and temperature_sensor_enable() again, the reading becomes wrong.

void app_main(void)
{
    ESP_LOGI(TAG, "Install temperature sensor, expected temp ranger range: 10~50 ℃");
    temperature_sensor_handle_t temp_sensor = NULL;
    temperature_sensor_config_t temp_sensor_config = TEMPERATURE_SENSOR_CONFIG_DEFAULT(10, 50);
    ESP_ERROR_CHECK(temperature_sensor_install(&temp_sensor_config, &temp_sensor));

    //ESP_LOGI(TAG, "Enable temperature sensor");
    //ESP_ERROR_CHECK(temperature_sensor_enable(temp_sensor));

    ESP_LOGI(TAG, "Read temperature");
    int cnt = 20;
    float tsens_value;
    while (cnt--) {
        temperature_sensor_enable(temp_sensor);

        // The first reading after disable/enable is incorrect
        ESP_ERROR_CHECK(temperature_sensor_get_celsius(temp_sensor, &tsens_value));
        ESP_LOGI(TAG, "Temperature value %.02f ℃", tsens_value);
        vTaskDelay(pdMS_TO_TICKS(1000));

#if 0   // Note, the second reading is correct.
        ESP_ERROR_CHECK(temperature_sensor_get_celsius(temp_sensor, &tsens_value));
        ESP_LOGI(TAG, "Temperature value %.02f ℃", tsens_value);
        vTaskDelay(pdMS_TO_TICKS(1000));
#endif
        temperature_sensor_disable(temp_sensor);

    }
}

Seems only the first reading after disable/enable is incorrect, the second reading looks correct.
Change #if 0 to 1 in above code will show that the second reading is correct.

Debug Logs.

No response

More Information.

No response

[suda-morris]

@AxelLin Thanks for reporting. It looks like we need to add some delay after temperature_sensor_enable. We will look into this issue ASAP.

[AxelLin]

I add the temperature sensor reading code to examples/bluetooth/nimble/bleprph.
It shows after disable-reenable the reading is wrong.
But after bt init, the reading becomes correct.

Below is the log, I also attached the modified code:

I (334) cpu_start: Min chip rev:     v0.0
I (339) cpu_start: Max chip rev:     v0.99
I (344) cpu_start: Chip rev:         v0.0
I (349) heap_init: Initializing. RAM available for dynamic allocation:
I (356) heap_init: At 408158D0 len 00066D40 (411 KiB): D/IRAM
I (362) heap_init: At 4087C610 len 00002F54 (11 KiB): STACK/DIRAM
I (369) heap_init: At 50000000 len 00003FE8 (15 KiB): RTCRAM
I (376) spi_flash: detected chip: generic
I (380) spi_flash: flash io: dio
I (384) sleep: Configure to isolate all GPIO pins in sleep state
I (391) sleep: Enable automatic switching of GPIO sleep configuration
I (398) coexist: coex firmware version: e41c5cb
I (403) coexist: coexist rom version 5b8dcfa
I (408) app_start: Starting scheduler on CPU0
I (413) main_task: Started on CPU0
I (413) main_task: Calling app_main()
I (453) example: Install temperature sensor, expected temp ranger range: 10~50 ℃
I (453) temperature_sensor: Range [-10°C ~ 80°C], error < 1°C
I (463) example: Enable temperature sensor
I (463) example: Read temperature
I (463) example: Temperature value 12.00 ℃
I (1473) example: Temperature value 35.00 ℃
I (2473) example: Temperature value 35.00 ℃
I (3473) example: Temperature value 35.00 ℃
I (4473) example: Temperature value 35.00 ℃
I (5473) example: Temperature value 35.00 ℃
I (6473) example: Temperature value 35.00 ℃
I (7473) example: Temperature value 35.00 ℃
I (8473) example: Temperature value 35.00 ℃
I (9473) example: Temperature value 35.00 ℃
I (10473) BLE_INIT: Using main XTAL as clock source
controller lib commit: [0ecb36f]
I (10473) phy_init: phy_version 230,c773401,Oct 30 2023,15:07:16
I (10513) phy: libbtbb version: 7243671, Oct 30 2023, 15:07:30
I (10513) example: Temperature value 14.00 ℃
I (11513) example: Temperature value 14.00 ℃
I (12513) example: Temperature value 14.00 ℃
I (13513) example: Temperature value 14.00 ℃
I (14513) example: Temperature value 15.00 ℃
I (15513) example: Temperature value 15.00 ℃
I (16513) example: Temperature value 15.00 ℃
I (17513) example: Temperature value 15.00 ℃
I (18513) example: Temperature value 15.00 ℃
I (19513) example: Temperature value 15.00 ℃
I (20513) example: Temperature value 15.00 ℃
I (21513) example: Temperature value 15.00 ℃
I (22513) example: Temperature value 15.00 ℃
I (23513) example: Temperature value 15.00 ℃
I (24513) example: Temperature value 15.00 ℃
I (25513) example: Temperature value 15.00 ℃
I (26513) example: Temperature value 15.00 ℃
I (27513) example: Temperature value 15.00 ℃
I (28513) example: Temperature value 15.00 ℃
I (29513) example: Temperature value 15.00 ℃
I (30513) NimBLE_BLE_PRPH: BLE Host Task Started
I (30513) NimBLE: Device Address:
I (30513) NimBLE: 40:4c:ca:41:15:ce
I (30513) NimBLE:

I (30513) NimBLE: GAP procedure initiated: extended advertise; instance=0

I (30523) uart: queue free spaces: 8
I (30523) example: Temperature value 16.00 ℃
I (31533) example: Temperature value 15.00 ℃
I (32533) example: Temperature value 15.00 ℃
I (33533) example: Temperature value 15.00 ℃
I (34533) example: Temperature value 15.00 ℃
I (35533) example: Temperature value 15.00 ℃
I (36533) example: Temperature value 15.00 ℃
I (37533) example: Temperature value 15.00 ℃
I (38533) example: Temperature value 15.00 ℃
I (39533) example: Temperature value 15.00 ℃
I (40533) main_task: Returned from app_main()

nimble_bleprph_read_temp.diff.txt

[AxelLin]

Just remind v5.1 and v5.2 need this fix.

[AxelLin]

A follow up fix: bc1478f

[AxelLin]

@mythbuster5 v5.1.3 does not include this fix.