Time_stamping_value?

[MMG]

Hi Nordic Devzone,

First i want to make sure that if the clock being used by softdevice is the LFCLK (32kHz) and its counter register is 24bits ? and which prescaler is being used? because I want to send the local time (clock value ) from one device to another using Bluetooth mesh connectivity, but when i'm reading the time of the receive message from the ( const access_message_rx_t * p_message) the value of timestamp is greater than 24 bits value actually its a 32bit value , so if the counter register in the LFCLK is 24 bits how would it be possible to count up to 32 bits value ? does it mean that the clock begin used for time stamping the receive messages is different than the clock used by softdevice ? And what is the best way to keep track of time while using the softdevice ?

Thank you in advance

[Hung Bui]

Hi MMG,

The timestamp you see in access_message_rx_t is the timestamp when the packet is received. It's a local timestamp counting from the start of current timeslot. Have a look at radio_handle_end_event() in scanner.c

And note that we use TIMER0 to count time, and it's 32bit. Not the 24bit RTC.

Currently we have no use of the timestamp in the receive package yet.

[MMG]

Hi Hung , Actually I'm interested in time for my application where global time could provide some more accurate data, I assume it would be similar to synchronization-like behaviour. Hence, I was wondering about global time and if i can use the timer_now() to get time on TIMER0 in my application? Have I understood it correctly that the softdevice is responsible for transferring and receiving packets then when it receives the las part of the message it will signal the reception and the the TIMER0 value will be assigned to the timestamp?

Also, timeslot mechanism is not that clear for me; For instance, how does the softdevice provide that and when does the timeslot begin and end? Would it be possible to determine when the TIMER0 will be reset or define a static timeslot length? Could you elaborate a little bit more on that?

Thank you very much for your help!