This test code shows how to configure deep sleep with the fastest wake up time pissible as far as I know (currently 44ms). Example is based on GPIO example from ESP-IDF
| GPIO | Direction | Configuration | Description |
|---|---|---|---|
| GPIO34 | output | Sends wake up signal to sleeper | |
| GPIO18 | input | pulled up, interrupt from rising edge | Receives ACK from sleeper |
| GPIO0 | input | pulled up, interrupt from rising edge | Tied to boot button on board, triggers wake up sequence |
| GPIO | Direction | Configuration | Description |
|---|---|---|---|
| GPIO18 | output | Sends wake up ACK signal to sleeper | |
| GPIO34 | input | tied to EX 6FD4 T0 wake up source | When pulled from high to low it wakes the board up |
When flashing the ESP32, it is usally necessary to disconnect pin GPIO2 from the MCU, otherwise the idf will not detect the board.
- Connect watcher GPIO18 with sleeper GPIO18
- Connect watcher GPIO2 with sleeper GPIO2
- Connect sleeper GPIO15 to GND
- Generate pulses on GPIO0 (boot button) to test wake up times.
- Two development boards with ESP32/ESP32-S2/ESP32-C3 SoC (e.g., ESP32-DevKitC, ESP-WROVER-KIT, etc.)
- Two USB cables for Power supply and programming
- Some jumper wires to connect GPIOs.
The default behavior of the system is going to light sleep, to test deep sleep define the macro DEEP_SLEEP in sleeper.c.
-
Serial flasher config
- flash SPI mode -> QUIO (improvement of ~5ms)
- flash SPI speed -> 80MHz (improvement of ~5ms)
-
Component config
- default log verbosity -> no output (improvement of ~120 ms)
-
Bootloader config
- bootloader log verbosity -> warning (improvement of ~100ms)
- bootloader optimisation level -> optimize for performance (-O2) (improvement of ~ 5ms)
- skip image validation when exiting deep sleep (improvement of ~55ms)
-
Connect sleeper GPIO15 to GND. It disables bootloader prints at startup. (improvement of ~15ms)
| Metric | Deep sleep | Light sleep | Comments |
|---|---|---|---|
| Wake up time | 44ms | 4ms | Wake up from deep sleep implies full reset, while, from light sleep, it resumes execution |
| Consumption | 9mA - 11uA | 15mA - 2mA | Consumption is tied to the board used, mainly to the built in voltage regulators |
Find a more detailed consumption analysis among diferent boards here.