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The ESP32 has multiple power-saving modes, and deep sleep is one of the most effective for reducing power consumption. In deep sleep, most of the chip’s components, including the CPU and RAM, are powered down, leaving only essential peripherals running to wake the device when needed.

Key Features of Deep Sleep

  • The CPU, most of the RAM, and peripherals are turned off.
  • RTC (Real-Time Clock) memory and RTC peripherals remain active.
  • The chip can be woken up using specific triggers (e.g., GPIO, timers, touch sensors, or external signals).
  • Power consumption can drop as low as 10µA, making it ideal for battery-powered applications

Wake-Up Sources

  1. Timer Wake-Up – Wake up after a defined time using the RTC timer.
  2. Touchpad Wake-Up – Wake up when a capacitive touch sensor is triggered.
  3. GPIO Wake-Up – Wake up when a specific GPIO pin changes state.
  4. ULP Coprocessor Wake-Up – A low-power co-processor that can monitor sensors and wake up the main CPU when necessary.
  5. External Wake-Up – Wake up via an external signal, such as a button press.

Power Consumption Comparison

ModePower Consumption
Active~160-240mA
Light Sleep~0.8-5mA
Deep Sleep~10-150µA
Hibernation~5µA

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Deep Sleep,

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