EC25 reboot/restart best strategy?

IoT Modules LTE Standard Module
1

Hi,

I’m wondering what would be the best strategy to correctly reboot an EC25 modem. Here is my use case :

  1. I can shutdown power supply of the modem.
  2. I can send any AT command to it.
  3. I do not have control of the PWRKEY pin. It is pulled down with a 10k resistor.

What I am doing right now is periodically cut off the modem supply, wait a little bit and activate again the supply. But I have read that:
image

So I would like to do things properly.

I initially planned to send the AT+QPOWD=0 command, however the modem reboots immediately (as PWRKEY is pulled to ground).

So my questions are :

  1. Is a power shutdown necessary when it comes to trying to recover from a modem abnormal state ? I think hard reboot is always the good way.
  2. AT+QPOWD=0 is a software reboot, right ? Would it be suffisant to help recover from an abnormal state ?
  3. Could I do the following : reboot by sending AT+QPOWD=0, and just after cut off the power supply ? The modem will still be booting so it won’t have any network access yet. Is it a good idea ?

I would appreciate any help.

Regards,

2

I am very glad to see that you are serious in your questions. I hope my answers can help you:

  1. Power off is just power off. It can be used as a solution to restore the abnormal state of the modem, but it may not be effective sometimes

  2. AT+QPOWD=0 is a hard reboot. It works the same way as PWRKEY. at+cfun=1,1 The AT command is a soft restart

  3. If you do not have any network access rights, I suggest that you use at+cfun=0/at+cfun=1 these two AT commands to capture log analysis.

ps: The module can be shut down in the following ways:

Normal shutdown: Power off through the PWRKEY pin control module

Normal shutdown: Send the at+qpowd command to shut down the device

------ Thank you

1 Like
3

Actually, in the docs, I only read
AT+QPOWD Power off
Nothing about reboot/power cycle, in Quectel_EC25EC21_AT_Commands_Manual_V1.2
Is the docs wrong ?

4

Hi, AT+QPOWD=0 indeed forces the module to immediately shut down. Have a look at Quectel_EC25_Hardware_Design_V2.2.pdf. (p. 42-45)

If PWRKEY is pulled down to ground, then after shutting down, the module will immediately power on again. I made some tests, and it seems indeed to behave this way.

5

I also just tried it, and it looks like, the modem really reboots. However, it is very unpleasant, to have docs like “Quectel_EC25EC21_AT_Commands_Manual_V1.2”
not being accurate. Thanx for the reference to the Hardware_Design.