BLE Sleep mode RAK11160

RUI
1

Hi @carlrowan @beegee @sercan

I’m working with the RAK11160 module, without using the RUI3, using the STM32CubeIDE and AT commands for the ESP32C2.

Within the AT commands, there’s an AT+SLEEP=2 command called Light-sleep mode.

According to the documentation, this mode only works with a 32kHz crystal. I have a few questions.

  1. Did the RAK11160’s electronic design include a 32kHz crystal for the ESP32C2? The RAK documentation only mentions crystals for the STM32.

  2. If it’s not included, how do you put the entire module into sleep mode while connected to BLE? With the RAK11720 and the RUI3, there’s an api.sleep.all(ms) command; which allows me to send the BLE to sleep in connected mode, I don’t know if using its RUI for the RAK11160 there is a similar command, and how they make it work for BLE.

Espressif documentation info

Only Bluetooth mode.

When Bluetooth LE is advertising, CPU will automatically sleep and RF will be periodically closed according to advertising interval of Bluetooth.

When Bluetooth LE is connected, CPU will automatically sleep and RF will be periodically closed according to connection interval of Bluetooth.

Note. In only BLE mode, only BLE Light-sleep and BLE Modem-sleep modes are available. Use the command to enable BLE Light-sleep, and use the command to enable BLE Modem-sleep.AT+SLEEP=2 AT+SLEEP=0

For Light-sleep mode in BLE mode, users must ensure external 32KHz crystal oscillator, otherwise the Light-sleep mode will work in Modem-sleep mode.

2

Hi Andres,

For the RAK11160’s ESP32-C2, there is no 32kHz Xtal and only the main xtal at 26Mhz. The approach on low power is turn off the ESP32-C2 via a GPIO controlled by the STM32WL.

The BLE of RAK11160 is fully dependent on the features provided by espressif so api.sleep.all(ms) will not work.