[Q2698/Fw7.52] How to exit Sleep mode through UART w/o DTR

I’m working in order to replace an “old” Q2686 on an existing board by a Q2698. On this hardware I have to control the modem’s sleep mode from an external application (through UART#1). Unfortunately, I can’t use any I/O to wake it up because none are connected to the modem … and certainly not DTR.

So, I put the modem in Sleep mode with AT+W32K=1,0 (Ignoring DTR)
Formerly, I was able to wake my “old” Q2686 like this:

<CR>		<-- Send carriage return

Now, Q2698/Fw7.52 doesn’t answer anymore to the command and stays in Sleep mode.

Reading the documentation, I understand that there is no way to do what I need, which is disappointing because I was able to do so with Q2686 …

Any suggestion would be welcome.

I’ve found a work around. Spamming AT+W32K=0 finally wakes up the modem:

OK			<-- Wake up after a few tries

Sounds like providence. Can I rely on it, especially with the next firmware upgrade?

  1. Does DTR work at all in Q2698 yet?
  2. Is FW7.52 for Q2698 released officially or is it still a beta/rc?

In general I wouldn’t trust the workaround you found unless Sierra says that spamming AT commands is a supported way of waking the module up.

With Fw R752_28_A1_10 : Yes
I did a lot of test, everithing seems correct.


Neither do I, unless I have to …

In my opinion,you have to design a new board and use DTR to control the sleep mode.