Higher Deep Sleep Consumption after first TCP connection

Hello! I’m using the SARA SFF with the R4X libraries and nb-IOT connectivity with great success. Using the low power sketch I get a deep sleep consumption of 15uA but when I try to implement deep sleep after sending a message the best current consumption I can get is around 75-80 uA. If I sleep before sending the message I can achieve the 15uA in my message sending sketch, but once I sleep after sending the first message, I can only get get the previously mentioned 75-80uA. A

Any tips that could help me lower the consuption to levels near the sleep before sending a message? Thank you

Hi @nunof,

This is as low as you can go in sleep after the modem is initialised.
Some settings are saved on the sim card and therefor some power is still running there.
There is no option to switch this off at the moment.

Best regards,
Jan

Hello @Jan,

Thank you very much for the update. If that’s the case, thank you, I just thought I was doing something wrong. This is because ublox announces 8uA in PSM mode, which with the sleep of the SODAQ Sara SFF of 15uA, should equal around 23-25uA.

Thank you, once again!

Hi @nunof,

The current you found is for the sara ship only.
On our board you have other components like the microcontroller, sensors.
Most of the time the microcontroller is not just in sleep, but also a RTC with WDT timer is running.
All taking a bit of current.

Best regards,
Jan