I’m wondering what would be the best strategy to correctly reboot an EC25 modem. Here is my use case :
I can shutdown power supply of the modem.
I can send any AT command to it.
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:
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 :
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.
AT+QPOWD=0 is a software reboot, right ? Would it be suffisant to help recover from an abnormal state ?
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.
I am very glad to see that you are serious in your questions. I hope my answers can help you:
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
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
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
April 13, 2023, 6:51am
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 ?
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.
April 13, 2023, 7:36am
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.