RTCWDT_RTC_RESET on light sleep

[CamargoF]

Hi folks,

I have developed a product that runs on the ESP32-S3 very well and is stable. However, when I attempted to save energy by replacing `delay()` with light sleep at the end of my `loop()`, the ESP32-S3 started rebooting, reporting an RTCWDT_RTC_RESET error.

From my research, it seems that the WDT_RTC generates a timeout to prevent the system from sleeping indefinitely due to bad programming, which is helpful. However, I haven’t been able to find a way to adjust the RTC timeout interval or reset the RTC timer.

I've noticed that people have been reporting this issue in forums since 2021, but no solution has been provided.

I would greatly appreciate any assistance.

The code I am using is:

Code: [Select all] [Expand/Collapse]

1.     // Sleeps 20ms on loop(), instead of delay()
2.     esp_sleep_enable_timer_wakeup(20 * 1000);
3.  
4.     // Keep domains active
5.     esp_sleep_pd_config(ESP_PD_DOMAIN_RTC_PERIPH, ESP_PD_OPTION_ON);
6.     esp_sleep_pd_config(ESP_PD_DOMAIN_RTC_SLOW_MEM, ESP_PD_OPTION_ON);
7.     esp_sleep_pd_config(ESP_PD_DOMAIN_RTC_FAST_MEM, ESP_PD_OPTION_ON);
8.  
9.     // Get a nap (20ms light sleep)
10.     esp_light_sleep_start();

GeSHi © Codebox Plus Extension

Best regards

Fernando

[aliarifat794]

Please review the power domain settings to check if the system's memory and peripherals are correctly powered during light sleep.

[CamargoF]

As I mentioned before, the product was running without any problem, until I tried to activate the light sleep.
The power supply looks fine.
I was not able to detect any glitch.

[CamargoF]

I tried to add the call for light sleep, from ESP-IDF, but also fails.

Code: [Select all] [Expand/Collapse]

1. #include <esp_sleep.h>
2.  
3. #ifndef  RTC_WDT_STG_SEL_OFF
4. #   define RTC_WDT_STG_SEL_OFF             0
5. #endif
6.  
7. #ifndef  RTC_WDT_STG_SEL_INT
8. #   define RTC_WDT_STG_SEL_INT             1
9. #endif
10.  
11. #ifndef  RTC_WDT_STG_SEL_RESET_CPU
12. #   define RTC_WDT_STG_SEL_RESET_CPU       2
13. #endif
14.  
15. #ifndef  RTC_WDT_STG_SEL_RESET_SYSTEM
16. #   define RTC_WDT_STG_SEL_RESET_SYSTEM    3
17. #endif
18.  
19. #ifndef  RTC_WDT_STG_SEL_RESET_RTC
20. #   define RTC_WDT_STG_SEL_RESET_RTC       4
21. #endif
22.  
23. #include "rtc_wdt.h"                           // from ..\Arduino15\packages\esp32\hardware\esp32\2.0.16\tools\sdk\esp32s3\include\esp_hw_support\include\soc
24.  
25.  
26.  
27. void watchdogResetRTCWDT() {
28.   // rtc_wdt_feed() = linha 130 de C:\Users\Projetos\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.16\tools\sdk\esp32s3\include\esp_hw_support\include\soc\rtc_wdt.h
29.   // rtc_wdt_feed(); // FAILED
30.  
31.   // Trying to access the register directly
32.   // Extract from C:\ESP\esp-idf\components\esp_hw_support\rtc_wdt.c
33.   REG_SET_BIT(RTC_CNTL_WDTFEED_REG, RTC_CNTL_WDT_FEED);
34.   // FAILED}
35.  
36. /*
37.  * @brief   Disable the RTC watchdog (RTCWDG).
38.  */
39. void watchdogEndRTCWDT() {
40.   // rtc_wdt_disable() = line 123 of ...\Arduino15\packages\esp32\hardware\esp32\2.0.16\tools\sdk\esp32s3\include\esp_hw_support\include\soc\rtc_wdt.h
41.   // rtc_wdt_disable(); // FAILED
42.  
43.   // WRITE_PERI_REG(RTC_CNTL_RTC_WDTCONFIG0_REG, 0);
44.  
45.   // Trying to access the register directly
46.   // Extract from C:\ESP\esp-idf\components\esp_hw_support\rtc_wdt.c
47.   REG_SET_BIT(RTC_CNTL_WDTFEED_REG, RTC_CNTL_WDT_FEED);
48.   myRtc_wdt_set_stage(RTC_WDT_STAGE0, RTC_WDT_STAGE_ACTION_OFF);
49.   myRtc_wdt_set_stage(RTC_WDT_STAGE1, RTC_WDT_STAGE_ACTION_OFF);
50.   myRtc_wdt_set_stage(RTC_WDT_STAGE2, RTC_WDT_STAGE_ACTION_OFF);
51.   myRtc_wdt_set_stage(RTC_WDT_STAGE3, RTC_WDT_STAGE_ACTION_OFF);
52.   REG_CLR_BIT(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_FLASHBOOT_MOD_EN);
53.   REG_CLR_BIT(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_EN);
54. }
55.  
56. /**
57.  * @brief   Copied rtc_wdt_set_stage() from C:\ESP\esp-idf\components\esp_hw_support\rtc_wdt.c
58.  */
59. esp_err_t myRtc_wdt_set_stage(rtc_wdt_stage_t stage, rtc_wdt_stage_action_t stage_sel)
60. {
61.     if (stage > 3 || stage_sel > 4) {
62.         return ESP_ERR_INVALID_ARG;
63.     }
64.     if (stage == RTC_WDT_STAGE0) {
65.         REG_SET_FIELD(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_STG0, stage_sel);
66.     } else if (stage == RTC_WDT_STAGE1) {
67.         REG_SET_FIELD(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_STG1, stage_sel);
68.     } else if (stage == RTC_WDT_STAGE2) {
69.         REG_SET_FIELD(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_STG2, stage_sel);
70.     } else {
71.         REG_SET_FIELD(RTC_CNTL_WDTCONFIG0_REG, RTC_CNTL_WDT_STG3, stage_sel);
72.     }
73.  
74.     return ESP_OK;
75. }
76.  

GeSHi © Codebox Plus Extension

Even calling watchdogResetRTCWDT() or watchdogEndRTCWDT() before esp_light_sleep_start(), the RTCWDT_RESET continues.

I have no other idea about what to do. I appreciate any help.

Best regards,

Fernando

[boarchuz]

Can you increase the sleep time (eg. 5s) to determine if it's having issues while asleep or upon wakeup?

Can you share more of your code, especially immediately after esp_light_sleep_start?

Can you add some tracing on the very next line after esp_light_sleep_start? Ideally simple like toggling a GPIO but serial output might work.

Are you certain there's no other serial output? Even if you increase logging level?