Historia

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
..
main	Add support for 32k XTAL as RTC_SLOW_CLK source	2017-04-26 12:43:22 +08:00
Makefile	add deep sleep wake up example	2017-02-22 18:40:31 +08:00
README.md	add deep sleep wake up example	2017-02-22 18:40:31 +08:00
sdkconfig.defaults	add deep sleep wake up example	2017-02-22 18:40:31 +08:00

README.md

Example: deep sleep

This example illustrates usage of deep sleep mode and various wakeup sources.

The following wake up sources are configured:

Timer: wake up the chip in 20 seconds
EXT1: wake up the chip if any of the two buttons are pressed (GPIO25, GPIO26)
Touch: wake up the chip if any of the touch pads are pressed (GPIO32, GPIO33)
ULP: wake up when the chip temperature changes by more than ~5 degrees Celsius (this value hasn't been characterized exactly yet).