Another question about low power consumption


Firmware: 7.43
Software: Developer Studio 1.1.2.
Module: Q2686H

Again, I want to ask a question about the low power mode.
First would like to note that already read the themes for this issue:

First idea: In order to translate the modem into a low power mode when turned off GSM, you should:

  1. Taking care of events to awaken (CALA or RTC Timer)

  2. Go to 32k mode = 1) AT+W32K and turn off gsm in my case AT+CPOF, 2) DTR set to low, 3) Reboot.

  3. Go to another Sleep mode with GSM turned off 1) AT+WBHV = 1,2, 2) DTR set to low, 3) Reboot

  4. And another Alarm mode = AT CPOF 2. ON / OFF pin to OFF

  5. Return DTR and wait for Event for awake

Second idea: Wake up modem without the use of external assistance (controller, processor, a simple flip-flop, etc.) is not possible (Or not in your case?). In modes AT+W32K and AT+WBHV for this should be returned to a state of DTR HIGH, and in sleep mode to access GPIO anymore. While AT+CPOF (ALarm mode) must have control output ON / OFF.

Third idea: Use to control output ON / OFF only the one GPIO, having a RESET STATE High - GPIO37 in Q2686H (RXD1) is not possible due to lack of access to the GPIO.

I would therefore ask those who have already managed to convert your modem in the regime of low energy:
What are the details you pointed out for yourself?
What do you consider wrong in my reasoning?
What issues are marked while falling asleep / waking up with big OpenAT programs? (Because the system state should be maintained before the reboot)

Please, I beg your most any comments and responses.


We use one I/O line to control sleep on our produict. I seem to recall you just need to iinto sleep and the I/O retains its state once it is sleeping. Once it wakes up with CALA, it is like a reboot and the unit runs again. It works ok for us.