LTE high current consumption

[akshayjames]

Hi

The test application I am running is sending sensor values read from PySense to an MQTT broker via LTE M1 connection.
It goes to sleep for 30 seconds for the next update. It continues in a loop.
The LTE current consumption is high all the time, about 236mA (wifi disabled).

How can I turn off / reduce power of LTE while not transmitting?
Power consumption is critical in the IoT project I am working on.

[akshayjames]

@jmarcelino Any update on the fn to enable LOW power LTE option?

[akshayjames]

@jmarcelino
Okay. Thank you for your support.
Will wait for the update. I will develop the application meanwhile.

[jmarcelino]

@akshayjames
You cannot just enable PSM because the PPP session running to provide IP networking is keeping the LTE modem active. Support has to come from a much lower level (LWIP layer)

[akshayjames]

@jmarcelino
Oh. Thank you for the information.
Till the firmware is released, for now can I enable PSM with AT commands?
When I check the The Power Saving Mode Setting, it is enabled. (via AT command +CPSMS?)
But that doesn't seem to reduce the power consumption of the LTE chip. How can I set it correctly?

[jmarcelino]

@akshayjames

There isn’t a currently way yet sorry, for now you must disconnect and then reattach/reconnect - in the future Pycom will support PSM + eDRX but I don’t have a planned release date I can share.

[akshayjames]

@jmarcelino
Thanks for the fast reply.
Yes LTE M1 connection is used for sending data. Sorry for not mentioning that. (I'll edit that right away.)

Yes I tried adding init(), attach(), connect() before sending and disconnect(), deinit() before going to sleep. That works.
But about 10 - 15 seconds is used for the connection establishment + disconnecting.
In the application loop, now the update interval is 30 seconds, so I can compensate for this time. But I want the update interval to be configured less than 10 seconds also. (I want to send data via LTE at 10 sec interval also.)

Any way to bring the LTE chip to Low power when not transmitting?

[jmarcelino]

@akshayjames
Can you clarify if you are using the LTE connection to send data?

To turn it off you’d call LTE.disconnect() and LTE.deinit()