WP7609 Current Draw on Low Power Mode?

IoT Modules
1

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?

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I’m running R16.3 TELSTRA firmware.

2

see if this helps:

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

3

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.

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

4

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

5

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

6

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

7

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

8

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

9

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.

10

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?

11

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)

12

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.


AT!entercnd="A710"
AT!custom="HSICENABLE",0
AT!reset

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.