RTC_DATA_ATTR and struct

[hellraise007]

Is it possible to store data under struct like the one below in RTC memory so I can retain the values of all the objects on wake up

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struct Button {
  const uint8_t PIN;
  volatile uint32_t numberKeyPresses;
  volatile bool pressed;
};

[ESP_Sprite]

Yes.

[hellraise007]

Yes.

Thanks for the reply. What is the correct syntax for this. This is illegal

Code: Select all

RTC_DATA_ATTR struct Button {
  const uint8_t PIN;
  volatile uint32_t numberKeyPresses;
  volatile bool pressed;
};

Code: Select all

struct Button {
  RTC_DATA_ATTR const uint8_t PIN;
  RTC_DATA_ATTR volatile uint32_t numberKeyPresses;
  RTC_DATA_ATTR volatile bool pressed;
};

I am not quite familiar with attributes.

[ESP_Sprite]

Do it where you actually allocate memory for your data. Something like this (untested):

Code: Select all

struct Button {
  const uint8_t PIN;
  volatile uint32_t numberKeyPresses;
  volatile bool pressed;
};

RTC_DATA_ATTR  struct Button my_button;