EC25-E Mini PCIe RI condition in Sleep Mode

I’m working with the EC25-E Mini PCIe module, in particular, the sleep mode feature (with AT+QSCLK=1).

Is it possible to completely turn off the host and maintain the EC25 sleep mode turn on?

I ask because if the host is in suspend mode, the EC25 keeps the sleep mode on, but if I turn the host off, the EC25 wakes up. I believe it is behaving like this because with the host turned off, DTR is pulled down.

So, is there any way to configure the EC25 to sleep even if host is shutdown?

Dear Miguelwon,
Thanks for your inquiry in Quectel forum.
Of course, you can let your host turn off and EC25 enter into sleep mode. You can use USB to connect to module, not UART port, so it is no need to connect DTR. Thanks!
But if that how could you wake up the module ? Or if there have any down-link data in this period, module can be wake up, but how could your know to power on your host?
So it is better to let the host and module enter into sleep, not power off. Thanks!

Hi and thanks for the reply.
So this is my setup:

  1. Raspberry Pi connected through USB to a 4G HAT with the EC25-E
  2. Arduino Nano connected to the same 4G HAT but using RX and TX
  3. Arduino Nano connected to the Raspberry Pi Global_EN pin (used to wake up Raspi).

All these three items are powered by Raspberry Pi 5V pin (event in total power off the Raspberry Pi keep the power pins on).

Why I want this setup? Because I want to put the Raspberry Pi to poweroff and wake it up with the Arduino when EC25-E receives a specific SMS. I will save a lot of battery with this setup.

The problem is the following:

Situation A:
1. I send the AT command “AT+QSCLK=1”
2. I suspend Raspberry Pi, that is, some services continue on, such as DTR in high.
3. EC25 module enters sleep mode.

Situation B (the problem):
1. I send the AT command “AT+QSCLK=1”
2. I poweroff Raspberry Pi, that is, it goes to a full poweroff state where DTR is low.
3. EC25 module does not enter sleep mode.

Dear Miguelwon,
Thanks for your updating.
For your application, it is really hard to meet your requirement.
As you know that if you want EC25E module enter into sleep mode, you can use UART or USB. When you use UART, you must make sure to meet the following requirement;
When you use USB, you also must make sure meet the following requirement.
To sum up, no matter you use which port, you must make sure AT+QSCLK=1, and DTR is in high level or open. So in the situation B, whether you can make sure DTR is in high not low level ? If you cannot do it, i think the module also have no method to solve your issue. Thanks!