Is WAKEUP_IN needed on the EC25?

I have a use case in which we have a host processor that could be powered off with the EC25 active and sleeping if it has nothing to do.

If the EC25 gets a “RING”, the host processor will be awakened by another low power processor.

I’m using USB communication between host and EC25.

If I understand sleep control, I believe I need to do the following:

  1. Ensure WAKEUP_IN is set to high to allow sleep (seems the name is backwards).
  2. Set AT+QSCLK=1
  3. Set USB_VBUS = low

Is WAKEUP_IN needed to control sleep on the EC25 or can I just leave it disconnected? It seems like this might have been provided to allow external hardware to prevent sleep for some reason.

There is no need to use the WAKEUP_IN pin to control sleep. When AT+QSCLK=1 and the USB_VBUS voltage is 0, the module will be awakened by pulling down the DTR pin level.

Thanks jouni.
I assume that DTR is only required if sleeping when using the UART?
We have left this pin disconnected.
Although we are using the UART when the processor USB is in use for another source, we will not need to sleep when using the UART.

As long as the module enters sleep mode, the module can be awakened by the following methods

  1. DTR pin is pulled low
    2.USB connected