current time service and calendar in nrf connect sdk

[aurna]

Hey there, Dev team!

I was wondering if you could help me out with using the "peripheral_cts_client" sample (struct bt_cts_current_time *current_time) to synchronize a timestamp of date and time (in the format like dd.mm.yyyy hh:mm:ss) on the peripheral, even when it's disconnected from the Bluetooth server. Essentially, I want to create a timekeeper that works like the calendar code for nrf5.

To do this, I'm planning on following these steps: 1) use the server to set the time on the peripheral device, 2) disconnect the Bluetooth connection, and 3) store the date and time when the button is pressed in non-volatile memory.

I'm currently using the nrf connect app on an iOS phone as the server and the nrf52 dk board as the peripheral with nrf connect sdk v2.3.0.

Thanks in advance for your help!

[Einar Thorsrud]

Hi,

The CTS sample demonstartes how to get the current data and time via Bluetooth. Internally, Zephyr has a 64 bit timer to keep track of the uptime, and that can be combined. If you store the system time when you get the current data and time via CTS, you can subsequently compensate for that to know the current data and time at any point after that. See Time Utilities.

[aurna]

Hey Einar!

I just wanted to say thanks for your help in clarifying things for me. With your guidance, I was able to successfully add the date and time feature to my application!

However, I do have a question about the accuracy of the rtCounter when it comes to maintaining time on the board. Do you happen to know if the oscillator is 250 ppm? And if so, do you have any suggestions on how to improve the accuracy? Thanks so much!

[Einar Thorsrud]

Hi,

The accuracy is given by your low frequency clock source. If you use the internal RC oscillator that will be 500 ppm when calibrated regularly (which is the default configuration). The reason for this not begin 250 is erratum 146. If you have an external 32.768 kHz on your board and use that, the accuracy of the crystal will dictate the accuracy

[lara]

can you share the api u used or sample code?

[Einar Thorsrud]

Hi,

The orginal post here refered to the peripheral_cts_client sample. If you have other questions, please make a new question.