esp-idf/examples/system
Ivan Grokhotkov 6353bc40d7 Add support for 32k XTAL as RTC_SLOW_CLK source
- RTC_CNTL_SLOWCLK_FREQ define is removed; rtc_clk_slow_freq_get_hz
  function can be used instead to get an approximate RTC_SLOW_CLK
  frequency

- Clock calibration is performed at startup. The value is saved and used
  for timekeeping and when entering deep sleep.

- When using the 32k XTAL, startup code will wait for the oscillator to
  start up. This can be possibly optimized by starting a separate task
  to wait for oscillator startup, and performing clock switch in that
  task.

- Fix a bug that 32k XTAL would be disabled in rtc_clk_init.

- Fix a rounding error in rtc_clk_cal, which caused systematic frequency
  error.

- Fix an overflow bug which caused rtc_clk_cal to timeout early if the
  slow_clk_cycles argument would exceed certain value

- Improve 32k XTAL oscillator startup time by introducing bootstrapping
  code, which uses internal pullup/pulldown resistors on 32K_N/32K_P
  pins to set better initial conditions for the oscillator.
2017-04-26 12:43:22 +08:00
..
deep_sleep Add support for 32k XTAL as RTC_SLOW_CLK source 2017-04-26 12:43:22 +08:00
ota OTA example readme: [typo]: Worflow to Workflow 2017-04-21 11:03:07 +10:00
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README.md

README.md

System Examples

Configuration and management of memory, interrupts, WDT (watchdog timer), OTA (over the air updates), deep sleep and logging.

See the README.md file in the upper level examples directory for more information about examples.