work around for NCSDK-14235: Timestamps that are sent in cloud messages drift over time

[Waqar Ahmed]

Hi Support,
we had recently upgraded our firmware to nrf Connect sdk1.9.0.

i read the following known issue for 1.9.0
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/known_issues.html?v=v1-9-0.

please can you confirm us is there any work around for the time drift problem in this sdk.

Thanks

[JONATHAN LL]

Due to summer holiday staffing is low and response time is slower than usual, pardon the inconvenience. 

We will get back to you as soon as we can. 

Regards,
Jonathan

[JONATHAN LL]

please can you confirm us is there any work around for the time drift problem in this sdk.

There is no workaround in NCS v1.9.X but you can cherry pick the commit from NCS v2.0.0

lib: date_time: Fix uptime to UTC time conversion · simensrostad/fw-nrfconnect-nrf@5b3af28 (github.com) 

This will fix the issue.

Regards,
Jonathan

[Waqar Ahmed]

Hi Jonathan,

I did make the changes according to this lib: date_time: Fix uptime to UTC time conversion · simensrostad/fw-nrfconnect-nrf@5b3af28 (github.com) 

but it give me wrong time stamp like 15278,

even after getting the time from modem.

the strange behave is that after 3 to 4 continuously publishing wrong timestamp when modem itself requested time from network then it start publishing timestamp.

so the issue is in function err = clock_gettime(CLOCK_REALTIME, &tp);

I am getting right timestamp here.

[JONATHAN LL]

Hi,

Can you enable CONFIG_DATE_TIME_LOG_LEVEL_DBG and provide the log. This should give us info on what exactly is going on.

Regards,
Jonathan

[Waqar Ahmed]

LTE cell changed: Cell ID: 38517279, Tracking area: 9010
RRC mode: Connected
Network registration status: Connected - roaming
D: UpPSM parameter update: TAU: 4200, Active time: 60
connection_poll_started
Next connection retry in 30 seconds
dating date time UTC...
D: Date time never set
D: Getting time from cellular network
D: Modem has not got time from LTE network, so not using it
D: Getting time from NTP server
AWS_IOT_EVT_CONNECTING
D: Connected to LTE, performing NTP UTC time update
D: Date time never set
D: Time obtained from cellular network (XTIME notification)
D: System time updated: 2022-08-09 11:53:15
DATE_TIME_OBTAINED_MODEM
D: IPv4 Address found 54.194.240.240
D: Time obtained from NTP server ntp.uio.no
D: New date time update in: 14400 seconds
D: System time updated: 1970-01-01 00:00:00
DATE_TIME_OBTAINED_NTP
D: Updating date time UTC...
D: Using previously obtained time
DATE_TIME_OBTAINED_NTP
D: Using send socket timeout of 60 seconds
D: AWS IoT broker connection request sent
D: MQTT client connected!
MQTT client connected!AWS_IOT_EVT_CONNECTED

Current RSRP -125
Publishing: {
"state":{
"reported":{
"logging_interval":300,
"app_version":"v2.0.0",
"ts":16743,
"battery":3600,
"psu":0,
"imei":"",
"lat":53.335768,
"long":-6.325005,
"ttff":0,
"last_loc_update_time":0,
"current_network_mode":"NBIOT",
"rsrp":-125,
"rsrq":-12,
"nbiot_rsrp":-125,
"lte_m_rsrp":0
}
}
} to AWS IoT broker
message length 356