ESP32-C3 too much current consumption

[asier70]

Hardware:

1. ESP32-C3-WROOM-02 XXH4 @80MHz
2. ESP32-WROOM-32D @80MHz

IDE: arduino 1.8.16
library: arduino-esp32 ver 2.0.1 (ver 2.0.0)
application: based on "BLE_uart.ino" (examples from the library)

Description:

Measured power supply current consumption:

1. ESP32-C3: 77mA (81mA for ver 2.0.0)
2. ESP32: 31mA (31mA for ver 2.0.0)

In my opinion for this BLE application ESP32-C3 consumes too much power. Module is even a little hot in touch.
The same BLE application running on ESP32 has over two times low power consumption.

What's wrong with ESP32-C3, that should be more energy-saving chip?

[asier70]

I've found the reason of this issue.
Arduino library for ESP32-C3 doesn't have "Bluetooth modem sleep" option enabled in sdkconfig. Classic ESP32 has this option enabled. I don't know what is the reason that Esspressif is not turning it on. With this option enabled current consumption decreases from 77mA to about 25mA.
Enabling this option and compilation is not trivial. Hint:
https://docs.espressif.com/projects/arduino-esp32/en/latest/esp-idf_component.html
Very low power consumption needs to use external 32kHz crystal, enabling power managment, enabling rtos idle sleep etc., but there is a problem with peripherials based on main crystal (like timers) - they are stoped during sleep periods.

[VojtechBartoska]

Hello, adding this as For reference issue so we can add this to our Documentation for Arduino users.

Was this issue resolved?

[asier70]

Still not resolved (2.0.3).

[VojtechBartoska]

@asier70 Will you be able to retest this on v2.0.4? Thank you.

[asier70]

I've just tested it using 2.0.4. Still the same high current consumption.
Arduino sdkconfig file for ESP32C3 still has modem sleep option disabled:

# MODEM SLEEP Options
#
# CONFIG_BT_CTRL_MODEM_SLEEP is not set
# end of MODEM SLEEP Options

I use manually changed this option:

# MODEM SLEEP Options
#
CONFIG_BT_CTRL_MODEM_SLEEP=y
CONFIG_BT_CTRL_MODEM_SLEEP_MODE_1=y
CONFIG_BT_CTRL_LPCLK_SEL_MAIN_XTAL=y
# CONFIG_BT_CTRL_LPCLK_SEL_RTC_SLOW is not set
# end of MODEM SLEEP Options

It needs manual project compilation, but helps for me.