WP7609 Current Draw on Low Power Mode?

I’m playing around reducing current draw with the WP7609. With no apps running (legato is running), and USB-SS enabled (low power mode), I see ~26s of ~5mA, followed by ~1min of ~30mA. This cycle continues.

Stopping legato altogether and going into low power mode also produces the same results.

I thought that this may be related to EDRX or CPSMS, and have changed the values, but the results are always the same. Then I tried without an active SIM. The value drops from ~5mA to ~2mA, but the ~30mA cycle still continues.

I set AT+CFUN=0 (and 4), to the same ~5mA and ~30mA cycles.

Does anyone know what this behavior is? And if possible, how to change these cycles?

I’m running R16.3 TELSTRA firmware.

see if this helps:

Also you can put module into ULPM by AT!POWERMODE=3 after setting the AT!POWERWAKE wake up source.

I’ve changed a few things and it behaves more as expected.
A new thing I’m seeing is that I can enter low power (idle) mode now using the sample smsApp and voiceCallApp. On receiving a registered event, like an SMS or call, the current goes back to an active current of around 42mA, before taking about a minute of inactivity to return back to idle mode.

I’d like to return to idle as soon as possible. Is this minute time period configurable?

see if you can send out USB selective suspend command to make the module sleeps ASAP:

Is there a way to do without USB SS command? This device won’t use USB in the future

will the current drop immediately if you disconnect the USB cable?

Almost immediately, if the wp76xx is not doing anything currently. This is on R17 Telstra by the way.
R16.3 Telstra behaves differently again.

then it won’t be a problem for receiving SMS as your will disconnect USB cable in your product, right?

With no USB, it will behave like USB-SS, right? So it will go into the low power mode without USB.
I still see the 1 minute delay before going into lower power mode when I boot the device without the USB plugged in. It behaves like USB-SS. I want to know if it’s possible to shorten this 1 minute delay.

Do you mean every time module receive the SMS without USB cable, it would have 1 minute high current before going to USB-SS mode?

Every time the module shows some activity, like receiving an SMS or call without a USB cable, it has 1 minute high current (20-30mA) before going into low power idle mode (as if going into USB-SS mode)

I don’t have much idea on this, but I remember in the past, I found on WP77 module, if I disable HSIC setting, i can help to go sleep mode.
You can see if there is any improvement.


you might also see “cat /sys/power/wake_lock” to see what is holding the module to go to sleep mode

Also please check your setting of AT+KSLEEP.