toggle rtc_gpio pullup in wake_stub cause immediate WDT reboot

[PeteDD]

I am trying to use as little power as possible so I want to turn off the pull-up on one port except when I am reading that port in a wake_stub. However, as soon as I add rtc_gpio_pullup_en(GPIO_NUM_27) to the code in the wake_stub, I get an immediate WDT reboot.

If I enable the pullup before going to sleep, then everything works fine however if my switch (rain tipping bucket) remains closed during the sleep, which it has a 50% chance of doing, then I am using power through the pull-up continuously which I am trying to avoid.

So, the question is, is it not allowed to toggle the rtc_gpio_pullup (that is, do a rtc_gpio_pullup_en, read the port, then do a rtc_gpio_pullup_dis) while in a wake_stub and then return to sleeping?

Here is a code example.
THANKS!

Code: [Select all] [Expand/Collapse]

1.  
2.  
3. // this is an example
4. // GPIO-17 has a switch to ground
5.  
6. #define RAIN_CNT_RTC_GPIO_NUM 17
7. #define RAIN_CNT_GPIO_NUM GPIO_NUM_27
8.  
9. static void RTC_IRAM_ATTR wake_stub(void)
10. {
11. #define PULSE_CNT_IS_LOW() \
12.   ((REG_GET_FIELD(RTC_GPIO_IN_REG, RTC_GPIO_IN_NEXT) & BIT(RAIN_CNT_RTC_GPIO_NUM)) == 0)
13. /
14.   rtc_gpio_pullup_en(RAIN_CNT_GPIO_NUM); // start using power
15.   if (PULSE_CNT_IS_LOW())
16.   {
17.     // do something
18.   }
19.   else
20.   {
21.     // do something else
22.   }
23.   rtc_gpio_pullup_dis(RAIN_CNT_GPIO_NUM); // stop using power
24.  
25.  
26.  // Set wakeup time in stub
27.   uint64_t time_in_us = WAKE_EVERY_X_SECONDS * uS_TO_S_FACTOR;
28.   deepsleep_for_us(time_in_us);
29.  
30.   // Print status.
31.   ESP_RTC_LOGI("wake stub: going to deep sleep");
32.  
33.   // clear out the UART buffer before going to sleep
34.   while (REG_GET_FIELD(UART_STATUS_REG(0), UART_ST_UTX_OUT))
35.   {
36.   }
37.  
38.   // Set the pointer of the wake stub function.
39.   REG_WRITE(RTC_ENTRY_ADDR_REG, (uint32_t)&wake_stub);
40.  
41.   // Go to sleep again
42.   CLEAR_PERI_REG_MASK(RTC_CNTL_STATE0_REG, RTC_CNTL_SLEEP_EN);
43.   SET_PERI_REG_MASK(RTC_CNTL_STATE0_REG, RTC_CNTL_SLEEP_EN);
44. } // end of wake_stub example
45.  

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[PeteDD]

I found another discussion about this here:
https://www.esp32.com/viewtopic.php?f= ... lup#p72193

and this page helps a lot:
https://github.com/espressif/esp-idf/b ... .c#L60-L81

Yes, using RTC_GPIO_PULLUP_EN in a wake stub WILL cause an immediate WDT reboot.

Yes, there is a way to do this using bit flipping and yes, like most ESP32 bit flipping, it is cryptic.

Code: [Select all] [Expand/Collapse]

1.  
2. //First, in the main code, set up the port:
3. #define RAIN_CNT_GPIO_NUM GPIO_NUM_27
4. #define RAIN_CNT_RTC_GPIO_NUM 17
5.  
6.     rtc_gpio_init(RAIN_CNT_GPIO_NUM);
7.     rtc_gpio_set_direction(RAIN_CNT_GPIO_NUM, RTC_GPIO_MODE_INPUT_ONLY);
8.     rtc_gpio_pulldown_dis(RAIN_CNT_GPIO_NUM);
9.     rtc_gpio_pullup_dis(RAIN_CNT_GPIO_NUM);  // start with pullup turned off
10.  
11. // then in the wake stub you can do this
12. #define RAIN_CNT_IS_LOW() \
13.   ((REG_GET_FIELD(RTC_GPIO_IN_REG, RTC_GPIO_IN_NEXT) & BIT(RAIN_CNT_RTC_GPIO_NUM)) == 0)
14.  
15.  REG_SET_BIT(RTC_IO_TOUCH_PAD7_REG, RTC_IO_TOUCH_PAD7_RUE_M);  // enable pull-up on GPIO-27
16.  
17.  if (RAIN_CNT_IS_LOW())
18.   {
19.     // do something
20.   }
21.   else
22.   {
23.     // do something else
24.   }
25.  
26.  REG_CLR_BIT(RTC_IO_TOUCH_PAD7_REG, RTC_IO_TOUCH_PAD7_RUE_M); // disable pull-up  on GPIO-27
27.  
28. // then do the other stuff to prepare and re-enter deep sleep  or fully wake up.
29.  

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